Three position selector for automated chuck

A automated chuck is provided with at least three user selectable operating modes, thereby enabling different functions to be performed during tightening and loosening of the chuck. In one exemplary implementation, the different user selectable operating modes of the chuck may be used to actuate a motor direction switch of the drill.

FIELD OF THE INVENTION

The present invention relates in general to a chuck for use on a spindle and, more particularly, to a automated chuck having at least three user selectable operating modes.

BACKGROUND OF THE INVENTION

Automated chucks have recently been introduced into the marketplace. Such chucks typically employ only two user selectable operating modes: a chuck mode and a drill mode. In the chuck mode, actuation of the drill motor drives the chuck jaws together or apart depending on the motor direction, thereby tightening or loosening a drill bit placed between the jaws. In the drill mode, the chuck jaws remain tightened and a secured drill bit rotates in the operational direction of the motor.

In the context of a drill having a variable speed motor, the chuck jaws may be tightened at a very high speed which makes the grip on a bit in the chuck very tight. However, the operator may attempt to loosen the chuck at a lower speed. In this instance, the chuck may not loosen. Therefore, it is desirable to provide an improved chuck assembly having at least three user selectable operating modes, thereby enabling different functions to be performed during tightening and loosening of the chuck.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, an automated chuck is provided with at least three user selectable operating modes, thereby enabling different functions to be performed during tightening and loosening of the chuck. In one exemplary embodiment, the different user selectable operating modes of the chuck may be used to actuate a motor direction switch of the drill.

In another aspect of the present invention, a sightline window may be formed in the chuck housing to provide the user feedback regarding the position of the chuck jaws.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1illustrates a automated chuck12in the context of a power drill10. The drill10is comprised of a housing14including a handle portion16and body portion18. A battery pack20is releasably attached to the handle portion16. A trigger22is provided on the handle16for selectively providing electric current from the battery pack20to a motor provided within the body portion18of the housing14. A motor direction switch23may also be provided on the handle16for selectively controlling the rotational direction of the motor. The motor is drivably coupled to a spindle which is in turn connected to the automated chuck12. Although shown in the context of a drill, it is readily understood that the automated chuck12is configured for use with a rotatable spindle and thus may be used with other types of power driven tools.

In accordance with one aspect of the present invention, the automated chuck12includes at least three user selectable operating modes, thereby enabling different functions to be performed during tightening and loosening of the chuck. In an exemplary embodiment, the different operating modes may be selected by rotating an outer sleeve of the chuck as will be further described below. The different operating modes may be demarcated on the outer sleeve as more clearly shown inFIG. 2.

An exemplary automated chuck12is further described with reference toFIGS. 3-6. While the following description is provided with reference to a particular chuck configuration, it is readily understood that the broader aspects of the invention are applicable to other chuck configurations.

The automated drill chuck12includes a core body40having a forward section42and rearward section44. The forward section42includes a through hole46that receives a drill bit therein. The rearward section44includes threads48in the through hole46that are adapted to be threadedly engaged with the drive spindle of the drill. The core body40includes a collar50provided with a plurality of guide channels52which intersect the through hole46at an angle. A plurality of jaw members54are received in the guide channels52, each jaw member54is provided with a threaded surface56on the outer side and gripping surface58on its forward inner surface. A threaded nut60surrounds the core body40and includes a tapered threaded surface62in threaded engagement with threaded surfaces56of jaw members54. The threaded nut60includes a plurality of recesses64formed on its forward surface and a number of teeth66formed on a rearward surface. A nut cover68is axially mounted around the forward section42of core body40and is in contact with the threaded nut60.

An impact ring70is ring shaped and embossed with a plurality of tooth-like impact members73with sloping sides around its periphery for mating with teeth66on threaded nut60. A coil spring74engages the impact ring70to flexibly support the rear of the impact ring70. A forward housing (chuck sleeve)76and rearward housing78encase the automated drill chuck12. The rearward housing78has forward and rearward openings for insertion of the forward section42of core body40. A locking ring80extends radially inward from the inside wall of the forward housing76, as best shown inFIG. 4. The forward housing76also includes a plurality of alternating deep and shallow locking recesses82,84disposed on a rear end thereof. A wear ring86is provided with corresponding deep and shallow recesses88,90and is disposed against the rear end of forward housing76. The deep and shallow locking recesses88,90of the wear ring86receive tooth-like members72on impact ring70. The rearward housing78covers the rearward end of the forward housing section (chuck sleeve)76and engages a stop92provided on the outer surface of the forward housing76to maintain the axial position of the rearward housing78relative to the forward housing76. The tooth-like members72of the impact ring70slidably engage axially extending recess channels94provided on the inner surface of the rearward housing78.

The rearward section44of the core body40is received through the rearward opening of the rearward housing78with a locking ring96engaging a recessed groove98provided on the rear section44of the core body40for securing the axial position of the rearward housing78relative to the core body40.

A nose sleeve100is provided with a rear positioning portion102and a forward nose portion104, with the positioning portion102having a cylindrical center through hole and a plurality of positioning ridges106raised from the inner wall for engaging the forward section42of core body40. A stop flange108is provided around the outer wall that forms a rest surface with the locking ring80on the forward housing76when the nose sleeve100is inserted onto forward section42of core body40.

Bearing rings110and washers112are provided to rotatably support the forward housing76. A joint member114, having a ring shape, is disposed between the coil spring74and rearward housing78. The joint member114includes a plurality of joint arms116which can be inserted through fan shaped slots118and join with bolts120on drill housing14, as best shown inFIG. 4, and are subject to the force from spring74and are situated in contact with front end of drill housing14. It is readily understood that the joint arms may be joined to other features on the front of the drill. In this way, the joint members114prevent rotation of the rear housing of the chuck to drill housing.

The operation of the exemplary automated drill chuck12is best illustrated by the description of a drill bit150being clamped by the chuck12. As shown inFIG. 4, drill bit150is inserted in the center through hole46provided in the forward section42of the core body40, with each of the jaw members54being retracted sufficiently to allow clearance for the drill bit150to be inserted. As the drive spindle32rotates in its operational direction, the core body40and jaw members54rotate therewith. Through the action of the tapered threaded surface62of nut member60with the threaded surface56of jaw members54, the jaw members54instantly incline upwards causing the gripping surface58of the jaw members54to move toward the axis of rotation and clamp down on the drill bit150. Nut member60does not rotate as it is engaged with the impactor ring70which is rotationally fixed by the rear housing78.

Once the jaw members54are prohibited from moving further forward due to the presence of the drill bit150, the threaded surface56and the tapered threaded surface62of the nut member60join in threaded engagement causing the nut member and core body40to rotate simultaneously. The forward housing76, rearward housing78, spring74, and impact ring70are joined together as one unit since joint member114is engaged to the bolts120on the housing14and thus, will not rotate along with spindle32.

FIG. 5shows a partial cut-away view of the automated chuck12in a drilling mode. By applying rotary force to the forward housing (chuck sleeve)76, the user adjusts the rotational position and selects the position of engagement between the shallow recesses90on wear resistant ring86and tooth-like member72. At this time, the impact ring70will be supported by the wear resistant ring86and move downward causing impact teeth73to disengage from teeth66on the nut member60causing the nut member60to be free of any contact while the nut member60is being rotated.

FIG. 6shows a partial cut-away view of the automated chuck in the “chuck” mode. From the “drill” mode, the chuck sleeve76may be rotationally positioned to either a “chuck tightening” mode or a “chuck loosening” mode. To restrict rotation of the chuck sleeve to three selectable positions, end stops87are defined on wear ring86. As the chuck sleeve is rotated, a protruding member117defined on an inner surface of the rearward housing78engages one of the end stops87. When actuated to either the “chuck tightening” or “chuck loosening” mode, the end stops87are arranged so that the tooth-like members of the impactor ring engage the deep recess of the wear-resistant ring86. In either of these positions, the automated chuck is considered to be in “chuck mode” where it is capable of tightening and/or loosening a drill bit as described below.

When the drill bit150rotates in the operational drilling direction and is subject to significant resistance or where the gripping force around the drill bit150is insufficient, the chuck sleeve76may be turned during operation or rest so the wear-resistant ring86is rotated so that teeth72of impact ring70engage the deep recesses88. At this time, the impact ring70will move upwards due to the flex action of the spring74and while the tooth-like members72engage with deep recess88, impact teeth73will simultaneously mesh with teeth66on nut member60and the rotationally positioned impact ring70moves up and down in recessed channels94provided in the rearward housing78to allow tighter engagement of the threaded surface62on nut member60with threaded surfaces56on jaw members54, eliminating the gap existing between the threads and increasing the stability of the gripping force of the jaws54on the drill bit150.

The impact ring is able to reciprocate axially against the biasing force of spring74so that the impact teeth73ride up the sloped sides of the teeth66as the torque increases. When the nut member60is fully tightened, the impact ring70will continue to axially reciprocate as the impact teeth73ride upon successive ones of the teeth60. Removal of the drill bit is obtained by reversing the rotational direction of the motor, thus causing the nut member to be driven in a reverse direction with the impact teeth73of the impact ring70providing a resistance to the rotation of the nut member60, thus causing the jaws54to retract. In other words, the rotary impact of teeth66of nut member60with rotationally stationary impact teeth73of impact ring70tends to cause the nut70to tighten or loosen depending upon the direction of rotation of the spindle32.

As noted above, actuation of the chuck sleeve amongst the different selectable operating modes, enables and/or causes an operation associated with the selected operating mode. For example, the forward housing76and the wear ring86may employ three sets of recesses, one set of recesses for each selectable position. In this example, a set of recesses having a medium depth is employed for a chuck tightening mode; whereas a different set of recesses having a deeper depth is employed for a chuck loosening mode. As a result, the engagement force between the impacting surfaces is greater in the chuck loosening mode than in the chuck tightening mode. In the drill mode, the applicable set of recesses remains relatively shallow as described above.

Referring toFIG. 7, the different user selectable operating modes of the chuck12may be used to actuate a motor direction switch23of the drill. To do so, the outer sleeve78of the chuck assembly may be interconnected via a linkage mechanism200with the motor direction switch23. In an exemplary embodiment, a ring gear202is formed along an inner surface of the chuck sleeve78. The linkage mechanism200is further defined as a pinion204coupled to an end of an actuating rod206, where the pinion204engages the ring gear202and the actuating rod206passes through a slot208formed in the motor direction switch23.

As the chuck sleeve78is rotated to select a desired operating mode, the rod206is rotated, thereby translating the motor direction switch23amongst its different positions. When the chuck sleeve78is rotated to a tighten mode, the motor switch23is overridden into a forward direction position as shown inFIG. 8A. When the chuck sleeve78is rotated to a loosen mode, the motor switch23is overridden into a reverse direction as shown inFIG. 8B. In a drill mode, the motor switch23is placed in an intermediary position, whereby the user is free to actuate the motor switch to either a forward or reverse direction as shown inFIG. 8C. In comparison with known automated chuck designs, the user is not required to select the proper motor direction, thereby reducing the number of steps to operate the chuck.

It is envisioned that other types of operations may be enabled by the different user selectable operating modes of the chuck. For example, the chuck mode selection mechanism may interact with the transmission of the drill. In an exemplary embodiment, a linkage mechanism interconnects the chuck mode selection mechanism with a user operated shifter lever for the transmission, thereby enabling translation of the lever amongst its different positions. When the chuck is placed in a loosening mode, the drill transmission may be shifted into a high speed mode. When the chuck is placed in a tightening mode, the drill transmission may be restricted to a lower speed mode than is permitted when loosening the chuck, thereby ensuring that the chuck is loosened at a higher speed than it was tightened. Further details regarding an exemplary implementation are described in U.S. patent application Ser. No. 11/354,643 entitled “Drill Chuck Actuator” which is being filed concurrently herewith by the assignee of the present invention and claims priority to U.S. Provisional Patent No. 60/654,849 filed on Feb. 18, 2005. The disclosure of these applications is incorporated herein by reference.

In a different example, different loads may be placed on the spring which biases the impactor ring into engagement with the nut during different chuck operating mode. For instance, a greater load may be placed on the spring when in a chuck loosening mode than in a chuck tightening mode. Different mechanisms for changing the spring load are further described in U.S. Patent U.S. patent application Ser. No. 11/355,386 entitled “Non-Slip Reverse Device for Automatic Chuck” which is being filed concurrently herewith by the assignee of the present invention and claims priority to U.S. Provisional Patent No. 60/654,852 filed on Feb. 18, 2005. The disclosure of these applications is incorporated herein by reference.

In yet another example, the chuck mode selection mechanism may cause different impactor rings to be engaged. During a chuck loosening mode, an impactor ring is engaged which employs less impacting surfaces than the impactor ring which is engaged during a chuck tightening mode, thereby allowing for greater rotational travel and speed between impacts. Further details regarding this example may be found in U.S. patent application Ser. No. 11/357,923 entitled “Drill Chuck” which is being filed concurrently herewith by the assignee of the present invention and claims priority to U.S. Provisional Patent No. 60/655,767 filed on Feb. 24, 2005. The disclosure of these applications is incorporated herein by reference. It is readily understood that two or more of these exemplary operations may be employed in combination. It is also readily understood that other types of operations are within the broader aspects of the present invention.

To provide the user feedback regarding the position of the chuck jaws, a sightline window220may be formed in the sleeve which encases the chuck assembly12′ as shown inFIG. 9. In one exemplary embodiment, the sightline window220is preferably sized so that a user can view the entire range of motion of the rearward end of the chuck jaws. However, it is also envisioned that the window is positioned to view the front end of the chuck jaws.

To improve viewing, an indicator222aligns with the rearward end of the chuck jaws54′. In this exemplary embodiment, the indicator222is biased by a spring224against the rear end of at least one jaw as shown inFIG. 10. As the chuck jaws54′ are opened or closed, the indicator222moves axially within the rearward sleeve of the chuck assembly, thereby providing an indication of the jaw position. In addition, graphics226adjacent to the window220correlate the jaw position to a diameter for a bit receptive opening formed by the jaws. It is envisioned that other techniques may be employed for providing an indication of chuck position.