Cutting edge lawn mower. How cleanly does a robotic lawnmower mow the lawn edge

US5383329A. Rotary lawn mower blade with replaceable cutting edge. Google Patents

Publication number US5383329A US5383329A US08/243,386 US24338694A US5383329A US 5383329 A US5383329 A US 5383329A US 24338694 A US24338694 A US 24338694A US 5383329 A US5383329 A US 5383329A Authority US United States Prior art keywords blade cutting edge grooves steps cutting Prior art date 1994-05-16 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired. Fee Related Application number US08/243,386 Inventor Harold P. Cornell, III Philip T. Werginz Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.) Switchblade Inc Original Assignee Switchblade Inc Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 1994-05-16 Filing date 1994-05-16 Publication date 1995-01-24 1994-05-16 Application filed by Switchblade Inc filed Critical Switchblade Inc 1994-05-16 Priority to US08/243,386 priority Critical patent/US5383329A/en 1994-05-16 Assigned to SWITCHBLADE, INC. reassignment SWITCHBLADE, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CORNELL, HAROLD P., III, WERGINZ, PHILIP T. 1995-01-24 Application granted granted Critical 1995-01-24 Publication of US5383329A publication Critical patent/US5383329A/en 2014-05-16 Anticipated expiration legal-status Critical Status Expired. Fee Related legal-status Critical Current

Links

• 240000000218 Cannabis sativa Species 0.000 claims abstract description 10
• 230000000295 complement Effects 0.000 claims description 18
• 241001270131 Agaricus moelleri Species 0.000 abstract description 6
• 239000000463 material Substances 0.000 description 10
• 239000000203 mixture Substances 0.000 description 6
• 239000000956 alloy Substances 0.000 description 4
• 229910045601 alloy Inorganic materials 0.000 description 4
• 229910052782 aluminium Inorganic materials 0.000 description 4
• REDXJYDRNCIFBQ-UHFFFAOYSA-N aluminium(3) Chemical class [Al3] REDXJYDRNCIFBQ-UHFFFAOYSA-N 0.000 description 4
• XAGFODPZIPBFFR-UHFFFAOYSA-N aluminum Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
• 229910000831 Steel Inorganic materials 0.000 description 2
• 238000003780 insertion Methods 0.000 description 2
• 229910052751 metal Inorganic materials 0.000 description 2
• 239000002184 metal Substances 0.000 description 2
• 230000004048 modification Effects 0.000 description 2
• 238000006011 modification reaction Methods 0.000 description 2
• 238000010079 rubber tapping Methods 0.000 description 2
• 239000010959 steel Substances 0.000 description 2

Images

Classifications

• A — HUMAN NECESSITIES
• A01 — AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
• A01D — HARVESTING; MOWING
• A01D34/00 — Mowers; Mowing apparatus of harvesters
• A01D34/01 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus
• A01D34/412 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters
• A01D34/63 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis
• A01D34/73 — Cutting apparatus

Abstract

A combination lawn mower blade (1) with replaceable cutting edge pieces (2a, 2b) mounted on the forwardly rotating cutting surfaces (25a, 25b) of the blade (1). The elongated blade (1) has top and bottom surfaces (8) and (16), respectively, with tips (24a, 24b) in a centrally located hole (7) for attachment to an engine shaft of a rotary lawn mower or the like. The blade (1) has a set of grooves (12a, 12b, 15a, 15b) and steps (13a, 13b, 14a, 14b) cut into the forward cutting surfaces (25a, 25b). The cutting edge pieces (2a, 2b) have a sharp cutting surface (10a, 10b, 22) which inclines upwardly on top to a flat top surface (20) and also have a flat bottom surface (11 ). A channel (26) in the cutting edge pieces (2a, 2b) is cut between the top and bottom surfaces (20, 11) and contains a set of groves and steps matching those on the blade (1) so the cutting edge pieces (2a, 2b) slide onto the blade (1) from the direction of the center of the blade (1). The set of grooves and steps on the blade (1) is cut so that a space is left between the cut and the tip of the blade so that the cutting edge pieces (10a, 10b) are blocked from flying off the blade (24a, 24b) due to centrifugal force during rotation. The blade (1) may have upwardly curved portions (3a, 3b) on the rearward edges near the tips (24a, 24b) of the blade opposite the cutting edge pieces (10a, 10b) to help produce aerodynamic lifting of the grass for better cutting.

Description

This invention relates to rotary lawn mowers and the like, and more particularly, to a replaceable cutting edge for lawn mower blades and the like.

Currently, when the blades of a rotary lawn mower become dull or worn, it is necessary to remove and replace the entire blade body with a new blade. Sometimes the blade can be sharpened while it is still attached to the lawn mower engine shaft, however, the latter is difficult as it requires lifting the mower and there is a risk of cutting oneself as the entire lawn mower blade has to be replaced, there is a high cost in terms of labor and material, especially for landscaping companies, which may be required to do so on at least a daily basis.

Thus, there exists a need for a lawn mower blade with a cutting edge that can be easily replaceable without having to replace the entire lawn mower blade body.

The prior patented art includes many replaceable cutting edges for lawn mower blades, but none just like the present invention. The prior patented art includes the following:

U.S. Pat. No. Inventor Issue Date 5,018,347 Feilen May 28, 1991 5,036,654 Malutich Aug. 6, 1991 4,779,407 Pattee Oct. 25, 1988 4,445,315 Roszkowski May 1, 1984 3,769,784 Jones Nov. 6, 1973 3,097,468 Johnson July 16, 1963 4,471,603 Veltin Jr. Sept. 18, 1984 3,514,935 Bonsor June 2, 1970 3,327,460 Blackstone June 27, 1967 2,932,147 Beeston, Jr. April 12, 1960 3,563,015 Renfroe Feb. 16, 1971 3,665,692 Hughes May 30, 1972 4,651,510 Malutich March 24, 1987 4,375,148 Beck March 1, 1983

The Feilen patent teaches a removable cutting edge that requires an entirely new blade with a cut, the forwarding rotating surfaces of the blade into which the cutting edge is inserted. In Feilen, the cut destroys the structural integrity of the blade. The Malutich patent teaches a different replaceable cutting edge that is secured by clips to a lawn mower blade. The Pattee patent shows another replaceable cutting edge that is attached by inserting a retaining arm on the blade into a slot in the cutting edge. The Roszkowski patent teaches yet another replaceable cutting edge that snaps onto the blade and emits an audible tone if the cutting edge is not installed correctly. The Jones patent shows another removable cutting blade in which the cutting edges are attached to the blade by a nut and bolt. The Johnson patent teaches replaceable cutting edges that slide into the blade and use a disk on the inner end to keep the blade in place against the centrifugal force caused by blade rotation. The Veltin, Jr. patent teaches another removable cutting edge for lawn mower blades which uses two bands to hold the edges to the blade. The Bonsor patent teaches another removable cutting edge which is held to the blade by nuts and bolts. The Blackstone patent shows removable cutting edges using rivets and a bolt/nut combination to hold it to the blade. The Beeston, Jr. patent teaches other removable cutting edges held on by rivets that slide into a slot on the blade. The Renfroe patent shows removable cutting edges that slide into channels at the end of the blades. The Hughes patent shows another removable cutting edge which is held on by nuts and bolts. The second Malutich patent teaches removable cutting edges which fit into specially designed mower blades. Finally, the Beck patent shows yet other removable cutting edge that is attached to the blade by insertion into a wedged slot on the blade.

Contrary to the above referenced prior patented art, the present invention allows the use of a fairly standard lawn mower blade which merely has a series of grooves and steps machined onto the forward cutting surfaces of the blades. The removable cutting edges contain a channel with matching grooves and steps which allows the edges to be easily and quickly slided onto the blades. As the present invention does not require a cut into the edges of the blades or snaps, nuts or bolts, the structural integrity and aerodynamic properties of the lawn mower blade are maintained.

The primary object of the present invention is to provide a combination rotary lawn mower blade with replaceable cutting edge pieces which eliminate the need to replace the entire blade when it becomes dull or worn.

Another object of the present invention is to provide such removable cutting edge pieces which are easily and quickly removable.

A further object of the present invention to provide a lawn mower blade for use with replaceable cutting edges which has a longer use life.

An even further object of the present invention is to provide a combination lawn mower blade and replaceable cutting edges that maintains proper aerodynamic lifting properties required for proper cutting.

An additional object of the present invention is to provide such a blade and cutting edge that reduces labor and material costs.

Another object of the present invention is to provide a lawn mower cutting blade which provides increased the safety for users.

The present invention fulfills the above and other objects by providing a blade with removable cutting edge pieces on forward rotating cutting surfaces for mounting through powered-rotary lawn mowers and the like. The elongated blade has a centrally located hole for attachment to an engine shaft and a set of grooves and steps on its forward rotating surfaces. The removable cutting edge pieces have a channel on the inner edge between the top and bottom surfaces which contains complementary grooves and steps to those on the forward rotating surfaces of the blade so that the cutting edge pieces can be slidably mounted on the blade. The blade may have a slanted lifting surface on its rearward rotating surface to lift grass for better cutting. In order to keep the cutting edge pieces from flying off the blade due to centrifugal force, the set of grooves and steps on the blade are not made all the way to the tip of the blade. Although the sets of grooves and steps may have any number of alternating steps and grooves in order to provide proper holding of the cutting edge to the blade, both the blade and the channel and the cutting edge would preferably contain at least two steps and grooves.

Other objects and advantages of this invention will become more readily apparent when a detailed description of a preferred embodiment is described in conjunction with the illustrations appended hereto.

FIG. 1 is a perspective view of a rotary lawn mower blade with replaceable cutting edge pieces installed on the blade;

FIG. 3 is a partial cross-sectional view of the blade and cutting edge piece along lines AA of FIG. 2;

Referring to FIGS. 1 and 2, the lawn mower blade 1 is shown with the replaceable cutting edge pieces 2a and 2b attached to the forwardly rotating surfaces of the blade 25a and 25b. The blade 1 contains a hole 7 for mounting the blade to the engine shaft of a rotary lawn mower or similar device. The blade 1 has a top surface 8 and a bottom surface 11 shown in FIG. 3. The top surface 8 contains upwardly slanted edges 9a and 9b opposite the replaceable cutting edge pieces 2a and 2b. The blade 1 contains two tips 24a and 24b which are preferably curved. The curved tips 24a and 24b, combined with upwardly slanted edges 3a and 3b opposite the cutting edge pieces 2a and 2b, provide the proper aerodynamic structure so that when the blade 1 is rotating it will lift the grass or other materials to achieve proper cutting. Each cutting edge piece 2a and 2b contains a sharp cutting surface 10a and 10b which has an upwardly slanting portion 4a and 4b and a flat top surface 5a and 5b.

FIG. 3 shows in more detail the forward rotating surfaces 25a and 25b of the blade 1 and one of the cutting edge pieces 2b. The blade 1, as well as the channel 23 in the cutting edge piece 26 contains a set of grooves and/or steps 12a, 12b, 13a, 13b, 14a, 14b, 15a and 15b, complementary to those in the blade 1, to properly hold the cutting edge piece 2b on the blade 1. Although the forward cutting edge 25a and 25b of the blade 1 may contain any number of steps and grooves, as illustrated herein, the blade and channel contain two sets of grooves and steps 12a and 12b and 14a and 14b with a step 13a and 13b in between and a step 15a and 15b near the outer edge of the blade 1. The grooves and steps are easily and quickly machined into the forward rotating surfaces of 25a and 25b of the blade 1 to yield a series of steps onto which the cutting edge piece 2b can be mounted when a channel 23 with complementary grooves and steps is cut between the upper surface 5b and lower surface 11 of the cutting edge piece 2b.

In FIG. 4 the set of steps and grooves are shown cut into the flanges 6a and 6b on the forward rotating surfaces 25a and 25b of the blade 1. It should be noted that the grooves and steps are not cut all the way to the tips 24a and 24b of the blade 1, but stop just short of the tips 24a and 24b. As a result of the latter, when the cutting edge pieces 2a and 2b are mounted the pieces do not slide off the tips of the blade 24a and 24b due to the centrifugal force which results when the blade 1 is rotated.

In FIG. 5 the end of the blade 1 is shown in cross-section with the top and bottom surfaces 8 and 16, respectively, and the steps and grooves 12a and 12b and 14a and 14b with steps in between 13a and 13b and outer steps 15a and 15b at the edge 18. On the rearward surfaces of the blade opposite the grooves and steps on which the cutting edge pieces are mounted is the upwardly slanted lift portion 3b with edge 9. This lifting portion 3b helps to create an upward force when the blade 1 is rotated, thereby raising the grass for better cutting.

In FIGS. 6 and 7 a cutting edge piece is shown by itself. Each cutting edge piece has a sharp cutting surface 22 on its forward edge and an upwardly slanting portion 21 on its top surface to a flat top 20. Between the top surface 20 and the flat bottom surface 11 of each cutting edge piece a channel 23 is cut containing a series of steps and grooves complementary to those steps and grooves on flange 6 of the lawn mower blade 1.

The lawn mower blade could be made of almost any rigid material, such as steel, aluminum or alloy. The blade 1 itself would be just like a conventional lawn mower blade, except rather than having a sharp cutting surface on its forward rotating edge, it would instead have a set of grooves and steps milled into its forward rotating edges. The cutting edge pieces, because they are not part of the blade, could be made of almost any material, but would preferably be made of a light metal or alloy, such as aluminum. The cutting edge pieces would be easily mounted to the blade by placing them on the inner beginning of the flange into the channel of the cutting edge pieces with a slight tap of a hammer or other tool. Removing the cutting edge pieces when they are worn and dull for sharpening or replacement would be easily accomplished by tapping inwardly the cutting edge pieces on the outer ends so that they slide off toward the center of the blade.

Although only one preferred embodiment of a lawn mower blade with replaceable cutting edge pieces has been described in detail above, all variations and modifications within the scope or equivalents of the claims are covered by this invention.

Claims ( 8 )

A blade with replaceable cutting edges on forwardly rotating cutting surfaces of the blade for mounting to powered rotary lawn mowers comprising:

an elongated blade having top and bottom surfaces, two tips, a centrally located hole for attachment to an engine shaft and a set of grooves and steps along a flange on both of its forwardly rotating cutting surfaces near the tip of the blade; and

replaceable cutting edge components having a flat bottom surface and a top surface inclined to a sharp cutting surface at a forwardly facing cutting end, said component having a notched channel between the top and bottom surfaces, said channel notched with a set of grooves and steps complementary to the grooves and steps on the blade so that the cutting edge component can be slidably mounted onto the blade.

The blade of claim 1 having upwardly slanted lifting surfaces on a rearward edge of the blade near the tip opposite the cutting edge component so as to provide for better cutting of grass.

The blade of claim 1 wherein the steps and grooves on the blade do not extend to the tip of the blade so that the cutting edge component does not fly off the blade due to centrifugal force created during rotation of the blade.

The blade of claim 2 wherein the set of steps and grooves on the blade do not extend to the tip of the blade so that the cutting edge component does not fly off the blade due to centrifugal force created during rotation of the blade.

The blade of claim 1 wherein the flange contains a set of grooves and steps consist of a first step on the top surface, a first groove cut into the bottom surface opposite said first step, a second groove cut into the top surface, a second step opposite the second groove and the cutting edge component contains a complementary set of grooves and steps so that the grooves and steps on the blade slide into the channel in the cutting edge component.

The blade of claim 2 wherein the flange contains a set of grooves and steps consist of a first step on the top surface, a first groove cut into the bottom surface opposite said first step, a second groove cut into the top surface, a second step opposite the second groove and the cutting edge component contains a complementary set of grooves and steps so that the grooves and steps on the blade slide into the channel in the cutting edge component.

The blade of claim 3 wherein the flange contains a set of grooves and steps consist of a first step on the top surface, a first groove cut into the bottom surface opposite said first step, a second groove cut into the top surface, a second step opposite the second groove and the cutting edge component contains a complementary set of grooves and steps so that the grooves and steps on the blade slide into the channel in the cutting edge component.

The blade of claim 4 wherein the flange contains a set of grooves and steps consist of a first step on the top surface, a first groove cut into the bottom surface opposite said first step, a second groove cut into the top surface, a second step opposite the second groove and the cutting edge component contains a complementary set of grooves and steps so that the grooves and steps on the blade slide into the channel in the cutting edge component.

US08/243,386 1994-05-16 1994-05-16 Rotary lawn mower blade with replaceable cutting edge Expired. Fee Related US5383329A ( en )

Priority Applications (1)

Applications Claiming Priority (1)

Family Applications (1)

Cited By (24)

Patent Citations (15)

Cited By (36)

Similar Documents

Legal Events

Owner name: SWITCHBLADE, INC., FLORIDA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CORNELL, HAROLD P., III;WERGINZ, PHILIP T.;REEL/FRAME:007005/0616

Effective date: 19940505

Effective date: 19990124

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

How cleanly does a robotic lawnmower mow the lawn edge

The goal of purchasing a robotic mower is usually to hand over lawn care to the garden helper. However, sometimes it is necessary to retouch the lawn edges.

With the acquisition of a robotic mower, garden owners actually hope to relinquish all power to their new garden helper. Unfortunately, lawn edges quickly become a nuisance when a small strip remains that needs to be trimmed manually because the robot simply cannot reach it. Luckily, there are methods to help you also mow the lawn edge.

A robotic mower helps keep the time spent on lawn care to a minimum. Not only are you free from mowing the lawn itself, but maintenance work is also normally less than with a classic gasoline mower. With that being said, pesky lawn edges may require manual reworking with a lawn trimmer or shears. After all, the overall appearance is not very neat if blades of grass sprout uncontrollably around the edges of the lawn. Not every robotic lawnmower really cuts the edges cleanly. This is often not possible for technical reasons alone. But never fear, there are ways to help minimize retouching.

Why do robotic lawnmowers leave an edge?

The fact that robotic mowers do not just mow lawns to the very edge is primarily due to the safety precautions offered by the device. Razor-sharp blades are well protected under the device and designed to stop automatically when lifted to avoid any possible contact. If blades protruded too far, they could pose a risk of injury.

So the width of the edge ultimately depends on the distance between the blades and the housing. If the blades are centered, this is quite large at 10-20 centimeters. In models with an edge-cutting function, the edge may be considerably narrower at approximately 5 centimeters. That sounds like a lot at first, but it’s no different from classic lawn mowers. They can also leave a small edge, which requires retouching.

Robotic mowers with edge-cutting function

Most robotic lawnmowers do not reach the edges due to their design, as the blade is centered underneath the device. There is a gap between the blade and the housing, which is especially noticeable when the robot drives along a wall. A strip of about 10-20 centimeters remains. Accordingly, the strip may increase with the size of the robot and the distance of the perimeter wire to the edge.

In the case of a robotic mower with edge-cutting function, the blade does not sit in the middle, but laterally under the device and even protrudes beyond the wheelbase. Still, there is a small distance to the outer edge of the housing. Nevertheless, this is limited to a much smaller width of about 6 centimeters so that the lawn edge is cut quite cleanly. The robotic lawnmower plans its mowing in such a way that it runs along the edges with the blade side to help keep the edge as small as possible.

A clean lawn edge can be achieved by laying a row of stones along walls so that the lawn does not grow right up against the wall, but leaves a small passable strip for the robotic lawnmower.

The correct laying of the boundary wire is important

For robotic lawnmowers with an edge-cutting function, it is particularly important to make sure the boundary wire is laid accurately. If you lay the wire too far inward, it will not be possible for the blade to reach the lawn edge. The ideal distance of the perimeter wire to lawn edges, walls or fences can be found in the manufacturer’s manual. Some models also have a ruler to help facilitate installation. These indications should definitely be followed, because the boundary wire is by no means the outer edge of the cutting width. If the wire is laid directly at the edge, the robotic lawnmower will go a little beyond it: in some models even as much as 30 cm.

If there are thoroughfares that are driven over, there is no need for a demarcation by the wire. The robot simply drives over them and mows the edges automatically. However, if the path represents the outer edge of the lawn, place the wire close to the path so that the robotic lawnmower cleanly takes the edge with it.

Caution should be exercised, however, if lawn edges are eliminated from flower beds. If the perimeter wire is too close to the edge, the robotic lawnmower risks slipping and getting stuck in the edge. The same applies along bodies of water or walls, to which a somewhat greater distance should always be maintained when laying the wire.

Guideline values for the perimeter wire distance for Robomow robotic lawnmowers

The distance of the perimeter wire from obstacles and beds differs depending on the manufacturer as well as from model to model. Almost all Robomow models have an edge cutting function, so the distance is comparatively small for traversable boundaries.

Model. Distance to fixed obstacle. Distance at ground level boundary

Lawn edging stones for the perfect edge cut

Not all robotic lawnmowers have a practical edge cutting function. Regardless, with a little ingenuity, lawn edges can be cut ideally even with models where the blade is centered. This will require either the appropriate advanced planning in your garden design or some reworking.

To do this, border the lawn and flower beds with lawn edging stones. These should be level with the ground and thus passable for the robotic lawnmower. Depending on the robotic lawnmower, a width of approx. 10 to 24 cm is recommended. It is also important to know whether the stone is adjacent to a wall or borders a bed behind it.

To prevent the lawn from growing into the bed, lay the lawn edging stones in two rows next to each other and stagger the joints in each case.

Next, lay the boundary wire as close as possible to the stones so that the robot uses one of the wheels to drive over the stones while the centrally positioned blade reaches the lawn edge.

Robotic lawnmower with three wheels

Some robotic lawnmowers have only three wheels instead of four. The front axle is substituted by a centrally placed wheel to help increase maneuverability but at the same time can make the devices more susceptible to getting stuck in soft ground. Accordingly, it is recommended to place lawn edging stones in such a way that the robotic lawnmower does not drive with the front wheel extending beyond the boundary.

Types of lawn edging stones

Lawn edging stones are available in a wide variety of designs and sizes. Which stone is suitable is first a question of personal taste. Secondly, the required width for the robotic mower should be included in your decision so that the lawn edge is cut as cleanly as possible. Possible stone types that would be appropriate for a robotic mower are:

• Dovetail stones
• Granite stones (the familiar cobblestone)
• Concrete sidewalk slabs
• Rectangular concrete paving

Of course, combinations of the stone types are also possible, which sometimes results in exciting designs.

Alternative bed edgings. not always suitable for robotic mowers

Alternatives to concrete edging stones are also bed edgings made of wood, metal or plastic or simply leaving the front edge of the bed free of vegetation so that the robot can use soil or humus as a navigation surface. In this case, however, regular edge trimming is necessary to avoid having your lawn grow into the bed. Although these bed edgings protect plants from undesirable intrusion of the robotic lawnmower, they are also not passable making reworking necessary. Metal bed edgings in particular also pose the risk of interfering with the signal of the robotic lawnmower.

Bed edging for robotic lawnmowers with grass sensors

For robotic mowers that use sensors instead of a perimeter wire, bed edgings are essential to provide a clear contrast between the lawn and the beds or to simply create a natural barrier that the robot cannot cross. Level lawn stones are therefore less suitable as a boundary. This means that manual reworking with a lawn trimmer is the only option.

MANUAL RETOUCHING WITH A LAWN TRIMMER

If you do not want to convert your garden, nor do you have a robotic lawnmower with an edge-cutting function, you can manually retouch the lawn with a lawn trimmer or (preferably battery-powered) lawn shears. Both are not particularly time-consuming or strenuous. Furthermore, it may be necessary to buy a second device for your lawn care. This may require more space for storage and additional costs.

Of course, which device is best suited depends on the size of your garden and the length of the lawn edges. For smaller stretches, manual lawn shears may even suffice. However, for larger gardens, a battery-powered lawn trimmer makes the job much easier. Maximum flexibility is offered by models with a swivelling cutting head.

FURTHER CRITERIA OF THE ROBOTIC LAWNMOWER FOR CLEAN LAWN EDGES

An edge cutting function is one thing. The other is a robotic lawnmower that can achieve an overall optimalt cut pattern.

• The most important criterion is sharp blades that really cut the lawn cleanly. The result of dull blades are frayed grass tips that tend to turn brown, which can eventually, cause your lawn to no longer look green, lush and healthy.
• A pendulum-mounted mowing deck is also helpful, as it is designed to provide a uniform cut even if the terrain is not completely level.
• In order to have a strong grip, especially on bumpy terrain or slopes, wheels with particularly good traction are recommended.

Robotic lawnmowers with an edge-cutting function mow edges cleanly to within a few centimeters but also reach their limits with vegetation that comes right up to walls and fences. To help avoid any kind of retouching, it is therefore advisable to edge the lawn with a margin of about 6 centimeters to the outermost edges. This will give you time to enjoy your manicured garden without still having to resort to the lawn trimmer.

Mower Blade Guide

When you look at your mower blade from the end, if the underside of the cutting edge is not flat to a table (parallel to the ground or center section), that will alter the angle of your grind. This is a tilt or twist forward, similar to a propeller. If you have a blade like that, you will want a Model 5005. The 5005 gives you the ability to easily adjust the grinding angle to compensate for the altered cutting edge angle. The video below goes into more detail. After reviewing the information below, if you are still unsure about your blade geometry, please contact us and we will help you choose the right model for your mower blades.

Blades With Potential Issues

We have encountered some mower blade styles that have issues being mounted in our vise. If you have one of these, you should check in with us first.

• Some eXmark 48” and smaller deck mowers have bi-level mulching blades where the cutting edge runs all the way into the center of the blade, beyond the center hole. This will cause mounting issues in our vise system that we do not yet have a solution for.
• Some mower blades have raised edges on the sides in the center mounting area. Not all, but some Toro, Snapper, and Cub Cadet blades fall into this category. There are other brands that may have this geometry as well. This causes issues but can be overcome by backing the vise screws out to raise them up so the blade will fit under them.
• Snapper Ninja mower blades are not able to be sharpened in our current units. We have not been able to create an adapter that will allow you to grind on the 4 blade edges.
• John Deere makes a mower blade for some older series of tractors that is too wide to fit in our jigs. These blades have a circular center hub that is 4 inches wide. We do not have an adapter or mounting solution for this type of mower blade.
• Dixie Chopper blades with the X—Blade system have raised centers that are stamped at an angle. This causes mounting issues in our vise system. We now have an additional adapter that can be used to properly mount the X-blades in our system.
• Honda riding lawn tractor mulching blades have a shape that will cause issues in our jigs. We have not been able to test or accommodate these blades yet. We do have an adapter for the Honda walk behind Microcut Twin Blade Sets.

Standard Mower Blades

The standard blade, as we refer to it, doesn’t have any altered angles along the cutting edge. It’s straight and simple. If you are looking to grind a 30 degree edge on these blades, you only need the Model 5002. If you want more angle options and versatility, check out the Model 5005.

John Deere Blades

John Deere mower blades can look deceptively like standard straight blades. But many, if not most of them, have a significant tilt or twist forward in the cutting section, so it is not parallel with the center section. This will alter the angle of the grind, so a setting beyond 30 degrees is necessary to compensate for the tilt. Our Model 5005 is the only jig we provide that makes it easy to choose steeper angle settings. Many John Deere customer have told us they needed to adjust their 5005 all the way to the 45 degree setting.

If the blade is used or worn, or has been previously sharpened, the angle may be beyond 45 degrees to the ground. If this is the case, it will take extra grinding to reset the angle. 45 degrees is the maximum angle adjustment in that direction. We have not found any new John Deere blades that needed an angle setting beyond 45 degrees.

John Deere also makes a mower blade (pictured above) that is too wide to fit in our jigs. These blades have a circular center hub that is 4 inches wide. We do not have an adapter or mounting solution for this type of mower blade.

Gator Mulching Blades

Gator mulching blades look more complex because of the mulching fins. But the cutting edge is the only part that needs sharpened. We have found that, due to a slight tilt forward along the cutting edge, the 35 degree setting is best to keep the factory edge on most Gator blades. We have found that most Ferris blades also have a slight tilt forward and work best with the 35 degree setting as well. The Model 5005 gives you the ability to grind at that angle.

Commercial Bi-level Mulching Blades

Bi-level mulching blades are a little more tricky. The outside cutting edge is parallel to the mounting surface. But the inside mulching section edge is raised and stamped at a different angle. We created the Model 5000 specifically to handle these. With a simple flick of the wrist, you can switch between the 30 degree setting on the outside edge or the 15 degree setting for inside mulching edge. In many cases, the Model 5005 is the better choice due to angle variances. Please read the text below …

If the underside of the outer cutting edge is not flat or parallel to the ground or the mounting section of your blade, it will alter your grinding angle. If that is the case, you will need a Model 5005 to compensate for the altered cutting edge angle.

Twisted High Lift Blades

We used to refer to these as high lift blades. But some mower blades are considered high lift without having the twisted end that makes these unique. That twist on the end alters the angle of the cutting edge. Since the cutting edge angles upward and isn’t parallel with the mounting surface, there needs to be an adjustment to compensate for that angle. The Model 5005 gives you the angle adjustments needed to fine tune your grinding edge to your preference. We see this type of blade on a lot of John Deere mowers. But there are other brands that incorporate a twisted high lift blade as well.

Honda Mower Blades

Honda Quadracut and MicroCut Twin Blade sets have a unique design and shape. We have fabricated an adapter so these blades can be mounted in our jigs. To match the factory bevel, we recommend the Model 5005 in conjunction with the Honda Adapter.

Counter-Rotating Mower Blades

Some mowers use blades that rotate in the opposite direction. We have heard these referred to as left-hand, counterclockwise, and counter-rotating blades. These will have the cutting edge on the other side of the blade. To adjust for this, all of our current Generation 2 models have extended guide arms. This gives you the extra range of motion needed to reach the cutting edge of your counter-rotating blades at the the bottom of the jig. We have seen these types of blades on many Walker mowers. But they are not exclusive to that brand. The 35 degree setting worked well with the Walker blades we have tested. For that reason, if you are planning to sharpen Walker mower blades, we recommend the Model 5005.

Hours: Mon-Fri 8am-4pm EST(with some holiday exceptions)

Free shipping is not included with phone orders.

The LawnmowerBlade that cuts itself sharp

Any landscaping professional knows that sharper mower blades make for sharper-looking lawns, but blades that maintain their sharpness can also improve a lawn-care business’s on-site efficiency and cut its maintenance costs.

Mowing lawns with LaserEdge® Eversharp™ blades means minimal maintenance and downtime associated with blade sharpening, increasing overall uptime and profits.

Redefining the Cutting Edge

High-quality, hardened steel blades equipped with the LaserEdge® Eversharp™ technology on their cutting edges have demonstrated their toughness and durability in field tests, even in the most abrasive conditions.

In one test, the LaserEdge® Eversharp™ cutting edge withstood 30 hours in severe sand conditions and became sharper during use. In a highly controlled durability test, the blade’s advanced technology performed remarkably, enduring multiple impacts from a 1-inch steel stake traveling at more than 200 mph.

Hours of Toughness

In an intense 50-hour field test in central Florida, mower blades with LaserEdge® Eversharp™ technology proved they “cut themselves sharp” when a new cutting edge emerged as the blade wore down.

In the test, a brand-new mower blade had LaserEdge technology applied on one cutting edge and was left untreated on the other edge. After putting the blade to work for 50 hours, the results were clear. The LaserEdge cutting edge was still sharp, and the untreated side was dulled and worn away.

Results will vary based on grass type, soil type and condition, and geographical region.

Cutting Costs, Boosting Bottom Lines

Increased Fuel Efficiency

Dull blades produce resistance, putting strain on the mower deck and making it difficult to maintain speed and efficiency. Mowing with a dull blade can reduce fuel economy by as much as 22 percent, which increases operating costs and reduces productivity.

Healthier, Greener Lawns

A dull blade shreds and tears grass, leaving it vulnerable to dehydration, browning, and disease. LaserEdge® blades cut grass cleanly, making it easier to deliver high-quality lawn care and in-demand enhancements such as lawn striping.

Blades Stay Sharp Longer

In abrasive conditions, a blade can get dull in as little as four hours, and lawn-care operations can go through dozens of blades a week, resulting in downtime and lost revenue. No matter the environment, a LaserEdge blade “cuts itself sharp,” reducing time spent sharpening.

Less Mower Maintenance

Blade replacement can be a dangerous undertaking. Attacking a dulled edge with a makeshift sharpening tool can irreversibly damage a blade and put workers in danger. LaserEdge blades dramatically reduce the frequency and risk of blade sharpening.

D.H. Steinegger, R.C. Shearman, T.P. Riordan and E.J. Kinbacher, “Mower Blade Sharpness Effects on Turf,” in Agronomy Journal 75 (1983): 479–480.

Savings Calculator

See how much you can save with LaserEdge® Eversharp™ lawnmower blades.

• 432 Saved on Fuel Cost
• 1575 Saved on Blade Sharpenings
• 2625 Additional Revenue Opportunity
• ( 960 ) Premium Spent on LaserEdge Blades

Calculations above are based off the following: type of lawn mower: 3-blade, 60-inch cut, gas-powered. Average gas price: 2.38. Lawn mower blade pricing: standard blade is 16. Average cost of sharpening: 5 per blade. Fuel savings: 11%. Blade removal and re-installation time: 30 minutes.

Frequently Asked Questions

How does LaserEdge ® Eversharp™ maintain a cutting edge that “cuts itself sharp”?

The LaserEdge Eversharp technology is applied to the underside of the cutting edge. As the blade cuts grass, the original blade material begins to wear away and exposes a new LaserEdge cutting edge, which is even sharper than the blade’s original sharpness.

Will I need to sharpen my LaserEdge ® Eversharp™ lawnmower blades?

LaserEdge blades “cut themselves sharp” and require minimal sharpening, but you should monitor cutting-edge wear. Sharpening is only needed if the new LaserEdge cutting edge is not presenting itself.

If I find the need to sharpen my LaserEdge ® Eversharp™ mower blades, how do I do so?

If you choose to re-sharpen your LaserEdge blade, do so in a safe, controlled setting with the proper equipment. Remember to prep the machine and remove the spark plug before removing the blade. Secure the blade to a work surface with a vise or clamp, and sharpen the blade with a file, bench grinder, or professional blade grinder. Ensure the blade is evenly sharpened and balanced before remounting on the mower deck.

How often will I need to change my LaserEdge Eversharp™ lawnmower blades?

The LaserEdge blade is designed to “cut itself sharp” and requires minimal sharpening over its life. The overall life of the blade will vary due to conditions, but its lifespan should be at least as long as a standard blade’s. In several of our tests, we found LaserEdge blades had longer lives.

How do LaserEdge ® Eversharp™ lawn mower blades perform in abusive mowing conditions?

The LaserEdge technology is an extremely hard, wear-resistant material. If you mow in conditions that regularly include rocks, curbs, out-cropping stones, and other hard objects, LaserEdge lawn mower blades may not be suitable for your operation.

A good test to see if LaserEdge is right for your operation is to inspect your worn blades. Worn blades that show excessive gouging, deep gashes, or large scraps may not see all the benefits of LaserEdge.

How long will it take for LaserEdge ® Eversharp™ to take effect?

This is highly dependent on geography, soil type, and cutting conditions. The magic of LaserEdge happens when the base blade material wears away at a faster rate than the harder, more wear-resistant LaserEdge material. In highly abrasive soil conditions (like sand), we have experienced standard blades wearing out in as few as 50 hours with blade sharpenings occurring as frequently as every 4 to 8 hours. In these areas, LaserEdge began exhibiting self-sharpening in as little as 5 to 10 hours. When using LaserEdge, these blades required no sharpening over the entire life of the blade. In less abrasive conditions, LaserEdge technology will take effect but over a longer time period.

How much do LaserEdge ® Eversharp™ lawn mower blades cost?

The price of LaserEdge blades will vary depending on the OEM and blade configuration. Although the LaserEdge will typically be more expensive than a standard blade, the benefits of consistently having a sharp cutting edge and increased uptime surpass the increase in blade price (see Savings Calculator).

Where can I purchase LaserEdge ® Eversharp™ lawnmower blades?

Most lawn mower Original Equipment Manufacturers (OEMs) are currently in the process of adding LaserEdge to their product line-ups. Be sure to talk to your local dealer about LaserEdge.

How do I get more information on LaserEdge ® Eversharp™ blades?

Fill out the contact form at the bottom of this page, and Fisher Barton will email you updates on product availability and news.

Get LaserEdge® For Your Business

Ready to bring this cost-effective, state-of-the-art mower blade technology to your lawn-care business? LaserEdge blades are currently available through select OEMs.

Available for the following brands through their independent dealers: (Click on the logo for information on available part numbers)

Connect With An Expert

We’re here to help and would love the opportunity to discuss your technical questions or application challenges.

Which Side of the Lawn Mower Blade Is Up? Tips and Tricks

Which side of the mower blade is up can be tricky for those who have only recently bought a lawn mower. Both sides of the mower blade have different purposes in grass cutting, and we understand that it might be confusing for new mower owners to differentiate between the two sides.

You cannot interchange both sides because this can damage the grass and the mower, sometimes even beyond repair.

In this complete guide, you will discover which side is up, along with several methods to determine this side practically.

• What Side of Your Lawn Mower Blade Is Up?

• – Clearly Written on the Blade
• – Doing the Wobble Test
• – The Wing Side Faces Up
• – The Non-cutting Side of the Blade Is Up
• – Rotate the Blade
• – Mulching Blade’s Top Side
• – Reel Lawn Mower’s Up Side

• – Prevent Damage to the Mower
• – Prevent Damage to the Grass
• – Top Side Cuts Grass Unevenly
• – Blade Gets Bent
• – The Crankshaft Might Break

• – Is the Right Placement of Lawn Mower Blades Side Important?
• – Are There Left and Right Blades for Lawn Mowers?

What Side of Your Lawn Mower Blade Is Up?

The side of your lawn mower blade that is up is the one with slightly raised edges. This side faces the lawn mower deck and has a dull cutting edge compared to the other side, which has a sharper cutting edge.

Here are some fool-proof ways to figure out which side of the lawn mower blade is actually up.

– Clearly Written on the Blade

Even the manufacturers understand that it gets confusing to tell both sides of the lawnmower blade apart. To make things easy for us, most of them put clear stamps to indicate which side is which on either side of the blade. The cutting side will be the “grass side” or the “downside,” while the other side will usually be the “upside.”

A sticker will be attached on both sides, if not a stamp. However, most of us lose this important sticker from our mowers with frequent use and washing. We like it best when proper engravings indicate both sides of the blade. Engravings make things so much easier and do not fade over time.

You can buy your stickers and stick them on the right side. Double-check that you are sticking these stickers on the right side first. If you have a laser engraving device, that would be even better than stickers.

– Doing the Wobble Test

It is okay if your lawn mower did not come with engravings or stickers marking the sides of the cutting blade. You can always tell which side of the blade is up using the wobble test method. This method always yields accurate results and is very easy to perform.

• First, you want to turn the mower off before doing anything with the mower blade. We even turn the spark plug off so that there isn’t any risk of the mower starting accidentally, either.
• Tilt the mower over on one side so that you can gain easy access to the blade. The mower needs to be balanced while tilted; otherwise, it will end up falling on you.
• Hold the lawn mower blade in one hand and the deck with the other hand.
• Tug and gently pull the mower blade downward and notice whether or not it wobbles.
• The blade will never wobble unless it has been attached the wrong way. Check that the bolt securing the blade with the mower is tight because this can also cause wobbling.
• If the wobble test indicates that the blade was attached incorrectly, remove it and reattach it on the opposite side. Perform the test again, and you will see how the wobble will have disappeared this time around.

– The Wing Side Faces Up

The side of the lawn mower blade that faces up has a blunted and dull cutting edge. The blunt edges have very slightly raised edges that look like tiny wings. They have been specially designed to produce an air vacuum and lift the grass blades. Once the air pressure lifts the grass blades in a vertical position, the blade’s cutting edge smoothly chops them down.

Sometimes, the raised wings on the edges of the upper side are more challenging to see visually. You will feel these wings rise if you run your finger along the edge. Using your tactile sensation, you can easily gauge which side of the blade is up and which is down.

– The Non-cutting Side of the Blade Is Up

Once you identify the cutting edge of lawnmower blades, you will never again confuse its two sides with one another.

The cutting edge is the one that should always face the ground because it is going to cut grass. Unless your blade is really old, the side with the cutting edge will be visibly sharper and shinier than the other side, which will have a dull and blunt edge.

The side of the blade with the blunt edge should always face upwards towards the lawn mower’s deck. If you need clarification on both edges after a simple visual inspection, use a piece of paper to see which edge cuts through it more smoothly.

– Rotate the Blade

Do you want a quick test to see whether you have fitted the mower blade correctly? Once you have finally installed the blade, keep the mower tilted to the side and rotate the blade in the mower. If the lawn mower has been tilted on the right side, move the blade in the counterclockwise direction.

If the blade has been installed correctly, the lower side with the sharp edge will be the leading edge. Otherwise, you must remove the blade and turn it upside down correctly.

– Mulching Blade’s Top Side

Mulching blades are different from regular mower blades because they cut grass and convert it into mulch. These mulched pieces can then be used to make compost, mulch, or rake for the benefit of your lawn. You can tell a mulched blade from a regular one just by looking at it, as it is more curved.

Most standard mulching blades have a serial and model number engraved onto them on the bottom. The smoother side will naturally be the upper side. These engraved numbers and wordings are easily visible under bright light, and this side should always be towards the grass.

The second way to tell which side of the mulching lawn mower blades should face up is by determining its cutting edge.

The cutting edge of the mulching blade is more easily identifiable than that of a regular blade. The blade’s non-cutting or the upper side will have slightly-raised edges or tiny flaps that bend upwards. You need to ensure that this side always faces the mower deck.

Lastly, look at which side of the blade has a beveled cutting edge. It is easier to notice this bevel under sunlight or light from a torch. This is most definitely the upper side of the mulching lawnmower blade.

– Reel Lawn Mower’s Up Side

The reel type of push mower is an exception because its cutting blades have no ups or downsides. The mowing blade of these mowers is arranged in a cylindrical manner and rolls like a wheel while cutting grass.

Since the edges of the blade are equally sharp, it doesn’t matter which side is up or down in a reel mower.

Why Is It Important To Attach Mower Blade Right Side Up?

It is important to attach mower blade right side up or the wings side up because this is what keeps the mower working properly. Otherwise, the mower and the cut grass end up incurring damages, and the grass will not be cut evenly.

– Prevent Damage to the Mower

You can imagine how a machine will react when its parts are not attached correctly. The grass-cutting property of the mower will be impaired negatively, and the inner working parts might get damaged too.

It also matters how long you have been misusing the mower blade. The longer the blade is used upside down, the more damage you can expect the mower to incur. The mower’s undercarriage, including the deck area, is particularly prone to damage. The engine gets strained as you push it harder to cut the grass.

– Prevent Damage to the Grass

When you accidentally install the blade upside down in a mower, the dull cutting edge has to do the work of cutting the grass. This edge was designed for something else and will do a terrible job overall. When the grass blades are cut using a dull blade, they get damaged.

Observe closely and you will notice that the grass seems crushed at its growing edges instead of being trimmed smoothly. A grass cut from the top side of the mower will grow back slowly and healthily. Your lawn will also not achieve the refined, clean look one expects after a grass-mowing session. It will look untidy and choppy, with patches of grass cut unevenly.

If you carry on cutting grass using the wrong blade side, your grass might eventually stop growing, and the lawn might develop bald patches.

– Top Side Cuts Grass Unevenly

Both sides of the blade have their purpose while cutting grass and must be installed correctly. When the blade gets attached upside down, the upside creates no air vacuum. The grass blades will only be forced to stand upright with a vacuum.

The result will be that the grass will be cut at varying heights throughout the lawn. This is the worst nightmare scenario for any lawn care enthusiast. A grass cut unevenly will also grow unevenly and make the lawn look like one huge mess.

– Blade Gets Bent

Mower blades installed wrongly upside down get damaged and broken easily, especially if you have been neglectful and have been using the mower this way for a long time. Remember those raised wings that are present on the upwards-facing side? These wings are supposed to face the mower deck and remain untouched as the blade rotates.

When one uses the blade upside down, these wings are constantly getting hit by the ground, grass blades, rocks, and other stuff.

Eventually, cracks develop and spread from these wings. or the blade gets bent. Once a lawn mower blade becomes damaged, it rarely gets fixed. You must let go of it and buy a new one instead.

– The Crankshaft Might Break

The crankshaft of the rotating mower blade is also at risk from blades installed improperly. The upside has raised edges and wings that frequently bump with stuff present on the ground. All the extra pressure generated is then transferred to the crankshaft.

If the blade gets cracked or bent, the shaft is also at risk of getting bent. In the worst-case scenario, you might have a broken crankshaft altogether.

This will lead to a much more extensive repair from a professional. All this effort and money could have been spared if only the blade had been attached with the right side up.

Frequently Asked Questions

– Is the Right Placement of Lawn Mower Blades Side Important?

Yes, the right placement of lawn mower blades side is important for cutting grass smoothly and working the mower. Otherwise, your grass will be cut in a choppy, rough, or uneven manner. In some instances, doing this might even damage your mower beyond repair.

This is because the top side of the blade has a blunt cutting edge and has not been built to cut grass. Instead, its job is to lift grass blades via an air vacuum so that the cutting edge of the lower blade can cut it.

– Are There Left and Right Blades for Lawn Mowers?

Yes, there are left and right blades for lawn mowers. This means that the blade’s cutting edge is either present on the right side of the blade or the left side. Consequently, a left-sided blade is not interchangeable with a right-sided blade.

When changing your old blade for a newer one, check which type of blade works with your lawn mower so that you buy the right one. A wrong side blade should not even be installed onto your mower.

Conclusion

This is the end of our exhaustive guide on which side of the mower blade is the upper side, and here are the key take-away points.

• The side with tiny raised wings and edges on it is the side that should be facing up towards the mower deck.
• The cutting edge of this upside is dull and blunt, while the cutting edge of the downward-facing side is sharper.
• If the lawn mower blade has been attached incorrectly, you can test it using the wobble method. An improperly attached blade is not going to stay still and will instead wobble.
• Fortunately, most companies either engrave the name of the sides on their blades or attach stickers.
• If your mower has no engravings, you can always post stickers to prevent future inconveniences.

Learning to identify both sides of the mower blade is very important because these are different from one another. Once you accidentally attach the mower blade the wrong way and keep using it like that, it could seriously damage the mower and the grass.