CROSS-REFERENCE TO RELATED APPLICATIONS
FIELD OF THE INVENTION
This application claims the benefit of U.S. Provisional Application No. 60/654,851, filed on Feb. 18, 2005, the disclosure of which is incorporated herein by reference.
- BACKGROUND OF THE INVENTION
The present invention relates to a drill chuck for use with a power drill device, and more particularly, to a drill chuck capable of being tightened or loosened by operation of the drill.
- SUMMARY OF THE INVENTION
Drill chucks are used in conjunction with power drills for releasably engaging a drill bit. Conventional drill chucks require a special tool for tightening and loosening the drill chuck onto the drill bit. Recently, drill chucks have been designed to be tightened by hand wherein a user can rotate a chuck sleeve of the drill chuck to cause the jaws of the drill chuck to engage and disengage a drill bit without the use of a tool. The user of the drill must rotate the adjustable chuck sleeve with one hand while holding a drill bit inside the jaw members until the drill bit is locked in place. More recently, drill chucks have been developed in which a drill bit can be inserted and with the chuck being disposed in a “chuck” mode, the operation of the drill will cause the chuck to be tightened or loosened, depending on the rotational direction of the drill. Many drills today have a multi-speed transmission that can be selectively switched by the operator. Currently, chuck devices that are capable of being tightened or loosened by operation of the drill may be tightened at high speeds, which makes the chucks very tight. If the user attempts to loosen the chuck on low speed, the chuck may not have sufficient torque to loosen the jaws from the drill bit.
The present invention provides a connection between the chuck shifting mechanism that causes the drill transmission to be shifted into high speed whenever the chuck is shifted from drill mode to chuck mode. Thus, the chuck is provided with its maximum loosening torque capability when utilized in the chuck mode.
According to yet another alternative design, a chuck is provided with a lockout device which engages the chuck and a shift mechanism of the multi-speed transmission device, and is adapted to prevent the chuck from being switched to the chuck mode unless the multi-speed transmission is in a desired high gear ratio.
BRIEF DESCRIPTION OF THE DRAWINGS
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of a drill incorporated with a drill chuck according to the principles of the present invention;
FIG. 2 is a perspective view of the drill chuck according to a first embodiment of the present invention, shown in the drilling mode;
FIG. 3 is a perspective view of the drill having the drill chuck according to the principles of the present invention with the chuck in the chuck mode;
FIG. 4 is a schematic view of a drill chuck incorporating a lock-out device according to a second embodiment of the present invention;
FIG. 5 is a schematic view of the drill chuck having a lockout device as illustrated in FIG. 4, with the chuck sleeve being shown in the chuck mode;
FIG. 6 is an exploded perspective view of an exemplary prior art drill chuck according to the principles of the present invention;
FIG. 7 is a partially sectioned view of the prior art chuck according to the principles of the present invention;
FIG. 8 is a partially sectioned view of the prior art chuck in its normal drilling mode according to the principles of the present invention; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 9 is a partially sectioned view of the prior art chuck in its chuck mode according to the principles of the present invention.
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With reference to FIG. 1, a drill 10 is shown incorporating a drill chuck 12 capable of tightening or loosening by operation of the drill according to the principles of the present invention. The drill 10 includes a housing 14 including a handle portion 16 and body portion 18. A battery pack 20 is releasably attached to the handle portion 16. A trigger 22 is provided on the handle 16 for selectively providing electric current from the battery pack 20 to a motor 24 provided within the body portion 18 of the housing 14. A multi-speed transmission device 26 is drivingly connected to the motor 24. The multi-speed transmission device is provided with a shift mechanism 28 including a shift lever 30 that is movable by an operator to change the gear ratio of the multi-speed transmission device. The multi-speed transmission device 26 includes a drive spindle 32 which is connected to the drill chuck 12. It should be understood that other devices, such as a torque adjustable clutch and/or hammer drill mechanism, can also be utilized in combination with the drill 10 without departing from the spirit and scope of the present invention.
With reference to FIGS. 6-9, an exemplary prior art drill chuck 12 that is capable of being tightened or loosened by operation of the drill will now be described. The drill chuck 12, as illustrated, is further disclosed in U.S. Pat. No. 6,247,706. Although the present invention will be described in combination with the exemplary drill chuck, it should be understood that the present invention is applicable to other drill chuck designs. The drill chuck 12 includes a core body 40 having a forward section 42 and rearward section 44. The forward section 42 includes a through hole 46 that receives a drill bit therein. The rearward section 44 includes threads 48 in the through hole 46 that are adapted to be threadedly engaged with the drive spindle 32 (FIG. 1). The core body 40 includes a collar 50 provided with a plurality of guide channels 52 which intersect the through hole 46 at an angle. A plurality of jaw members 54 are received in the guide channels 52 with each jaw member provided with a threaded surface 56 on the outer side and a gripping surface 58 on its forward inner surface. A threaded nut 60 surrounds the core body 40 and includes a tapered threaded surface 62 in threaded engagement with threaded surfaces 56 of jaw members 54. The threaded nut 60 includes a plurality of recesses 64 formed on its forward surface and a number of teeth 66 formed on a rearward surface.
A nut cover 68 is axially mounted around the forward section 42 of core body 40 and is in contact with the threaded nut 60. An impact ring 70 is ring shaped and embossed with a plurality of tooth-like impact members 73 with sloping sides around its periphery for mating with teeth 66 on threaded nut 60. A coil spring 74 engages the impact ring 70 to flexibly support the rear of the impact ring 70. A forward housing (chuck sleeve) 76 and rearward housing 78 encase the drill chuck 12. A locking ring 80 extends radially inward from the inside wall of the forward housing 76, as best shown in FIG. 7. The forward housing 76 also includes a plurality of alternating deep and shallow locking recesses 82, 84 disposed on a rear end thereof. A wear ring 86 is provided with corresponding deep and shallow recesses 88, 90 and is disposed against the rear end of forward housing 76. The deep and shallow recesses 88, 90 of the wear ring 86 receive tooth-like members 72 on impact ring 70. The rearward housing 78 covers the rearward end of the forward housing section (chuck sleeve) 76 and engages a wedge shaped stop 92 provided on the outer surface of the forward housing 76 to maintain the axial position of the rearward housing 78 relative to the forward housing 76. The tooth-like members 72 of the impact ring 70 slidably engage axially extending recess channels 94 provided on the inner surface of the rearward housing 78.
The rearward section 44 of the core body 40 is received through the rearward opening of the rearward housing 78 with a locking ring 96 engaging a recessed groove 98 provided on the rear section 44 of the core body 40 for securing the axial position of the rearward housing 78 relative to the core body 40.
A nose sleeve 100 is provided with a rear positioning portion 102 and a forward nose portion 104, with the positioning portion 102 having a cylindrical center through hole and a plurality of positioning ridges 106 raised from the inner wall for engaging the forward section 42 of core body 40. A stop flange 108 is provided around the outer wall that forms a rest surface with the locking ring 80 on the forward housing 76 when the nose sleeve 100 is inserted onto forward section 42 of core body 40.
A pair of bearing rings 110A and washers 112A are provided to rotatably support the forward housing 76. Additional bearing ring 110B and washer 112B provide a rotational support between the nut member 60 and collar 50 of core body 40. A joint member 114, having a ring shape, is disposed between the coil spring 74 and rearward housing 78. The joint member 114 includes a plurality of joint arms 116 which can be inserted through fan shaped slots 118 and join with bolts 120, or otherwise attached to the tool housing 14 on drill housing 10, as best shown in FIG. 7. Thus, the rearward housing 78, spring 74, and impact ring 70 are joined together as one unit since joint member 114 is engaged to the bolts 120 on the housing 14 and thus, will not rotate along with spindle 32. The joint member 114 is subject to the force from spring 74.
FIGS. 7 and 9, illustrate the chuck in the “chuck mode”. By “chuck mode,” it is meant that the chuck is operable to either tighten the jaws to firmly grasp the accessory or to loosen the jaws to allow removal of the accessory by operation of the drill. In the “chuck mode”, the chuck sleeve 76 and the wear-resistant ring 86 are rotated so that teeth 72 of impact ring 70 engage the deep recesses 88 in wear resistant ring 86. At this time, the impact ring 70 will move upwards due to the flex action of the spring 74 and while the tooth-like members 72 engage with deep recesses 88, impact teeth 73 will simultaneously align with teeth 66 on nut member 60. The rotationally positioned impact ring 70 moves forward in recessed channels 94 provided in the rearward housing 78 and is also capable of moving rearward against the biasing force of the spring 74.
As shown in FIGS. 7 and 9, a drill bit 150 is inserted in the center hole 46 provided in the forward section 42 of the core body 40, with each of the jaw members 54 being retracted sufficiently to allow clearance for the drill bit 150 to be inserted. As the drive spindle 32 rotates in its operational direction, the core body 40 and jaw members 54 rotate therewith. Initially, the nut member 60 does not rotate since it is coupled to impact ring 70 via engagement of teeth 66 with impact teeth 73. The impact ring 70 is held stationary by rear housing 78. Through the action of the tapered threaded surface 62 of the stationary nut member 60 with the threaded surface 56 of rotating jaw members 54, the jaw members 54 instantly incline forward causing the gripping surface 58 of the jaw members 54 to move toward the axis of rotation and clamp down on the drill bit 150. Jaw members 54 are prohibited from moving further forward due to the presence of the drill bit 150. When the tightening of the jaw members 54 is complete, the threaded surface 56 and the tapered threaded surface 62 of the nut member 60 join in threaded engagement causing the nut member 60 to then rotate simultaneously with the core body 40. As the nut member 60 begins to rotate, the impact ring is able to reciprocate axially against the biasing force of spring 74 so that the impact teeth 73 ride up the sloped sides of the teeth 66 as the torque increases. When the nut member 60 is fully tightened, the impact ring 70 will continue to axially reciprocate as the impact teeth 73 ride upon successive ones of the teeth 66. The sound of the parts impacting thereby is an indication that the chuck 12 is tightened. Loosening of the jaw members 54 is obtained by reversing a rotational direction of the motor, thus initially causing the nut member 60 to be driven in a reverse direction with the impact teeth 73 of the impact ring 70 providing a resistance to the rotation of the nut member 60, thus causing the jaws 54 to retract. In other words, the rotary impact of teeth 66 of nut member 60 with rotationally stationary impact teeth 73 of impact ring 70 tends to cause the nut 70 to tighten or loosen depending upon the direction of rotation of the spindle 32.
FIG. 8 shows a partial cut-away view of the chuck 12 in a “drilling mode”. In the drilling mode, the rotational position of the forward housing (chuck sleeve) 76 is selected such that the shallow recesses 90 on wear resistant ring 86 engage tooth-like members 72. At this time, the impact ring 70 will be supported by the wear resistant ring 86 and move rearward causing impact teeth 73 to disengage from teeth 66 on the nut member 60 causing the nut member 60 to be free of any contact while the nut member 60 is being rotated along with the core body 40 and jaw members 54. Thus, in the drill mode, the jaw members 54 which have been tightened onto the tool implement will tend to stay tightened since the impact ring 70 is held disengaged from the nut member 60.
The chuck 12 may be used in combination with a drill with a multi-speed transmission. In which case, the chuck, as described above, may be tightened at high speed, which makes the chuck very tight. If a user were to attempt to loosen the chuck on low speed, the chuck 12 might be incapable of overcoming the clamping forces to loosen the chuck 12. Accordingly, as illustrated in FIGS. 2 and 3, the forward housing 76 which is rotatable between a drilling mode position (FIG. 2) and chuck mode position (FIG. 3) is provided with an additional connector arm 200 which extends into the drill housing and interacts with the multi-speed transmission shift mechanism 28. When the chuck 12 is in “drill” mode, the arm 200 is in such a location that the drill shifter is permitted to be positioned in all speeds, including low, medium, and high (as designated by numerals 1, 2, 3). When the forward housing sleeve 76 is shifted to the “chuck mode,” the forward housing 76 is rotated as illustrated by arrow A in FIG. 3. The arm 200 also moves rotatably while engaging the corresponding arm 202 extending from shift lever 30 so that the shift lever on the drill is forced into high speed mode (position “3”). Thus, when the chuck 12 is in the chuck mode, the multi-speed transmission 26 of the drill 10 is automatically set to the highest speed.
In the illustrated example, the embodiment shows the high speed as the desired speed for operation in the chuck mode. However, it should be understood that any one of the selected speeds could be utilized for operation in the chuck mode. Thus, with the system of the present invention, the chuck 12, which is operable in a drilling mode and a chuck mode, is provided with an actuating device that is operable to switch the chuck 12 from the drilling mode to the chuck mode and simultaneously switch the multi-speed transmission device to a desired gear ratio. It is anticipated that it may also be desirable to switch the multi-speed transmission device to a lowest gear ratio during a tightening operation of a chuck. This could readily be accomplished using the principles of the present invention to move the shift lever to the desired position when the shift sleeve or forward housing of the chuck is moved to the chuck position.
It is also anticipated that the actuating device of the chuck 12 can be provided with separate independent positions for both a locking and unlocking mode of operating the chuck. In this scenario, the forward housing or shift sleeve 76 of the chuck 12 would further interact with the “forward/reverse” shifting mechanism of the motor 24 and would permit the switching of the shift mechanism to the highest gear ratio in a chuck-loosening mode while being switched to a lowest gear ratio in a chuck-tightening mode. In this way, it could be established that the lowest driving force would be used for tightening while the highest driving force could be utilized for loosening the drill bit.
With reference to FIGS. 4 and 5, a second embodiment of the present invention will now be described in which a lockout device 300 is engaged with the chuck 12 and the shift mechanism 28 of the multi-speed transmission device 26. The lockout device 300 is adapted to prevent the chuck 12 from being switched to the chuck mode unless the multi-speed transmission 26 is in a predetermined one of the multiple gear ratios (preferably the highest gear ratio). In particular, a pin 302, or other member, is supported by the housing and is axially biased by a spring 304 against the speed shifter lever 30. The shift lever 30 is provided with a cam surface 306 having a recess 308 (best shown in FIG. 5), such that the pin 302 engages the cam surface 306 which forces the pin 302 in an axially forward direction into engagement with a recess 310 provided in the forward housing 76′ of the chuck. The pin 302, while engaged in recess 310, prevents the forward housing or chuck sleeve 76′ from being rotated from the drilling mode position (FIG. 4) to the chuck mode position. When the shift lever 30 is moved to the highest gear position (position “3”) as illustrated in FIG. 5, the recess 308 in cam surface 306 is aligned with the pin 302 so that the pin is able to retract from the recess 310 provided in the chuck sleeve 76′ so that the chuck sleeve 76′ is then free to be rotated to the “chuck mode” position (FIG. 5). Thus, the lockout device 300 prevents the chuck 12 from being operated in the chuck mode unless the speed shifter 300 is in the desired position (in this case, the highest speed position). While the chuck sleeve 76′ is in the chuck mode position, the pin 302 is blocked from retracting a sufficient distance from recess 308 in cam surface 306 to thereby prevent the speed shift lever 30 from being shifted from the desired position. It is not until the chuck sleeve 76′ is rotated back to the drilling mode position (FIG. 4) that the recess 310 is aligned with the end of the pin 302 such that the pin 302 can be retracted sufficiently to allow the shift lever 30 to be moved from the “desired” position to one of the other speed positions. Thus, with the lockout device 300, it is ensured that the multi-speed transmission 26 will be moved to the desired gear ratio in order to allow the chuck to be operated in the chuck mode.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.