Clamped Drill In Hammer Chuck
A tool like a drill appeared in the house.
The drill is used for drilling various types of materials, therefore it is necessary to change the drill very often.
The first holes are drilled and the drill bit needs to be changed. How to pull the drill out of the drill with your own hands correctly?
Drill Chuck Design
Drill chuck design.
In all types of drills, the drill is installed in a special chuck. Using this tool, the drill is mounted on a rotating shaft, and the rotational movement necessary for drilling is transmitted to it. In this type of drill, such as a hammer drill, it also provides translational (impact) movement of the drill. Almost all drills use cam-type mechanisms.
The cam cartridge consists of a hollow body in the form of a cylinder along which the adjustment sleeve or ring moves. Inside the casing, cams with a conical cut are installed, which move along the guides, providing translational movement of the cams during rotation of the adjusting element. Due to the taper, the cams when moving up evenly converge relative to each other or evenly diverge when moving down.
The scheme of the drill.
To install the cartridge on the drill shaft in its lower part, a hole is made along the shaft diameter. The fastening can be due to a threaded connection or holes with a taper and a tight fit of the cartridge on a shaft having a reverse taper.
The drill is inserted in the center into the space between the cams. When the cams converge (clockwise rotation of the adjusting element), the drill is fixed in the cartridge, and when the cams diverge, on the contrary, it is released. To ensure reliable fastening, it is necessary to apply considerable force when rotating the adjusting element.
According to the method of fixing the drill, the cartridges are divided into ordinary (key) and quick-clamping. In the key, the adjusting ring is moved and tightened with a special key. When the key is rotated clockwise, the drill is secured in the chuck. An adjusting sleeve is installed in the quick-clamping device, the surface of which has a corrugation for the convenience of hand rotation. By manually rotating the sleeve clockwise, the drill is fixed in the chuck.
Keyless chucks come in two types: with one sleeve and with two sleeves. If the design provides only one sleeve, then it rotates relative to the drill body, which must be fixed motionless during installation. When using two sleeves, one of them is movable, adjusting, and the other is motionless. The rotation of the adjusting sleeve is carried out relative to the second sleeve, which must be fixed when installing the drill. In the design of the cartridge, to limit the tightening force, additional elements can be used in the form of a ratchet (located inside) or a locking spring mechanism with a button (the button goes into a special socket on the outside).
Causes of difficulty in removing the drill
Types of drills: a. Centerless spiral; b. Spiral with a center and cutters; in. Spiral with a helical center; g. Feather center; d. Center; e. Gimlet; f. Countersink; h. Groove; and. Cork.
In the process of working with a drill, sometimes difficulties arise when replacing a drill associated with removing a previously used drill from a chuck. This problem can be of varying degrees of difficulty, depending on the cause of the occurrence. The simplest and most common reason is the application of excessive force when clamping the drill, in the absence of restrictive mechanisms in the design of the cartridge. Such a phenomenon most often occurs when a shock method of influence is used to tighten the drill in the final stage, for example, the use of a mallet. Jamming of the drill can also occur if it is tightened forcefully when it is improperly placed in the space between the cams. This is typical when using a small diameter drill.
Clamped Drill In Hammer Chuck
A more complex tool jamming mechanism can occur when using a low-quality drill. So, if it is made of soft material, then when it rotates, metal chips can be removed from the surface, which clogs the gap between the cams and the drill, as well as between the cams. This can make cam breeding difficult when trying to loosen the drill. Difficulties in removal can occur if the drill bit sank too deep into the chuck during operation. The task is complicated if the drill, in addition to such jamming, also breaks at the level of the upper end of the cartridge.
The cause of the breakage of the drill in the drill chuck can be a violation of the drilling mode.
The reason for the destruction, in addition to using low-quality material, may be a violation of the drilling mode: unexpected tilt of the drill, excessive vertical load, an attempt to drill heavy-duty material, etc.
Finally, the reason that the drill cannot be removed can be jamming of the cartridge itself. There are several possible reasons. The first reason, not related to the failure of the cartridge, is due to the ingress of foreign particles that impede movement into the threaded area of the regulating element and the housing. Such particles can be dirt, metal dust or fine chips, etc. In this case, it is not possible to rotate the adjusting sleeve or key.
The reason that it is not possible to get a drill may be the failure of the cartridge. This can lead to both the presence of a factory defect and temporary wear on the cams or control element. The cause may be the failure of the spring locking mechanism, which does not release the control element when the button is pressed.
Easy drill removal
In order to remove the drill from the chuck, it is necessary to turn the adjustment sleeve.
In normal mode, the issue of extraction is solved very simply. By turning the adjusting sleeve or key counterclockwise, the cams are bred, after which the drill is removed. In the presence of a locking mechanism, rotation begins by pressing the lock button. When the adjusting element is rotated, the drill body (cartridge with one sleeve) or the stationary sleeve (cartridge with two sleeves) is fixedly fixed by hand.
If you cannot turn the sleeve or the key right away, you must try to increase the load or create a reinforced initial load pulse. The first attempt is to set the movement with a sharp jerk of the right hand, while ensuring the fixation of the drill with the left hand. The next attempt is a light hand punch on the key vertically or a palm punch on the sleeve in a tangent direction to the surface of the sleeve. If the manual method of exposure did not help to pull out the drill, then you should resort to using a mallet or a light hammer (preferably rubber). This tool strikes the key or sleeve. The strength of the impact increases as necessary. To increase the force, it is advisable to introduce a lubricant (oil) into the cam zone before impacts.
In cases where the drill bit is jammed strongly, the use of a vise can be recommended. To remove it, you must perform the following operations:
Another way to remove the drill from the drill is to use a vise.
- The jammed drill is firmly clamped in the vice so that the drill itself is parallel to the table.
- With a small hammer, tap lightly over the entire surface of the cartridge.
- Then light but sharp blows are made with a hammer on the sleeve vertically along the tangent to its surface.
- If the movement has begun, then the blows should be continued until the end of the drill shank appears.
- If the movement does not occur, then it is necessary to strengthen the blows. In this case, it is necessary to ensure that the surface is not damaged.
The effectiveness of the method can be increased if you use a gas key. It can be used only in the case of a metal cartridge. It is simply not possible to clamp it securely in plastic. The gas sleeve tightly clamps the sleeve. By rotating the gas key counterclockwise, the sleeve is rotated relative to the drill fixed in a vice.
The effect can be further enhanced by using two gas keys. In this case, the drill shaft or fixed sleeve (in the case of a cartridge with two sleeves) is fixed with a second gas key. Rotation counterclockwise is made with a gas wrench mounted on the cartridge adjustment sleeve; the second key must be fixed. Thus, the rotation of the sleeve relative to the drill and drill must be ensured at the same time.
Removing the chuck due to jamming of the drill
If jamming of the drill occurred due to the fault of the cartridge, then it must be removed from the drill shaft. There are two types of element fastening on the drill shaft: threaded and conical. With threaded fastening, the element is fixed in a vise, and the drill rotates counterclockwise relative to it. If there is a locking screw, it is unscrewed with a screwdriver or with a gas wrench.
With conical mounting, the cartridge is mounted on the shaft “in tightness”.
You can remove it by lightly tapping the hammer on the lower end.
Before this, the locking screw is loosened.
After removing it from the drill shaft, you can make the last attempt to remove the drill. For this, all internal elements (cams), together with the drill, are knocked out of the housing by light impacts on the upper ends of the cams.
The tool that is needed to pull out the drill:
- Gas key;
- Rubber mallet.
Jamming the drill inside the drill can cause certain difficulties when removing it. However, little effort and knowledge of the design of the cartridge will help to cope with this problem.