Automatic jaw control for reversible power tool

• US 4,526,497 A
• Filed: 03/15/1982
• Issued: 07/02/1985
• Est. Priority Date: 03/15/1982
• Status: Expired due to Fees

• Current Assignee: Jim J. Hatfield
• Original Assignee: Jim J. Hatfield
• Inventors: Hatfield, Jim J.
• Primary Examiner(s): Briggs, William R.
• Application Number:
  US06/358,030
• Time in Patent Office: 1,205 Days
• Field of Search: 279/1 K, 279/60-65, 279/1 B, 279/58, 279/56, 408/241 R, 408/240, 408/238
• US Class Current: 408/240
• CPC Class Codes: B23B 2231/06 Chucks for handtools having means for opening and closing the jaws using the driving motor of the handtool
• CPC Class Codes: B23B 2231/38 Keyless chucks for hand tools
• CPC Class Codes: B23B 31/1238 Jaws movement actuated by a nut with conical screw-thread
• CPC Class Codes: Y10S 279/902 Keyless type socket
• CPC Class Codes: Y10T 279/17615 Obliquely guided reciprocating jaws
• CPC Class Codes: Y10T 279/27 Separate chuck-actuating power source
• CPC Class Codes: Y10T 408/953 Clamping jaws

Abstract

A reversible drill, equipped with a chuck having a jaw guide, chuck jaws constrained by the jaw guide for radial advancement and retraction, and chuck jaw propulsion means for driving the chuck jaws in advancement and retraction, is equipped with a manually actuable clutch for easing the chuck jaw propulsion means into and out of engagement with the drill housing to, respectively, prevent and allow relative rotation between the jaw guide and the chuck jaw propulsion means. When the drill motor is driven in one direction of rotation, the chuck jaw propulsion means is immobilized relative to the drill housing and the chuck jaws are advanced radially toward each other to grip a drill bit. When the housing and chuck jaw propulsion means are eased together and the drill motor is driven in the opposite direction, the chuck jaw propulsion means is immobilized and draws the chuck jaws apart as the jaw guide rotates to release a drill bit. When the chuck jaw propulsion means is disengaged from the drill housing the drill is operable in a normal manner. An O-ring is positioned between the drill housing and the chuck jaw propulsion means and is operable independently of the clutch mechanism to exert a light drag on the chuck jaw propulsion means. Drill bits can be lightly seized and chuck jaws opened without engagement of the clutch mechanism.

Claims

1. In a reversible drill having a rotary drive shaft carried by a drill housing and having a chuck engageable for rotation with said drive shaft and formed with a jaw guide, chuck jaws constrained by said jaw guide for radial advancement and retraction relative to the axis of said drive shaft, chuck jaw reciprocating means journaled relative to said jaw guide, and coupled to said chuck jaws to selectively advance and retract said chuck jaws when said chuck jaw reciprocating means and said jaw guide are subjected to relative rotation in opposite directions, and manually actuatable clutch means for engaging and disengaging said chuck jaw reciprocating means relative to said drill housing to respectively prevent and allow relative rotation between said jaw guide and said chuck jaw reciprocating means, the improvement wherein said clutch means includes a clutch actuator mounted for movement relative to said drill housing, and including a bearing collar disposed coaxially about said drive shaft and riding on a spiral track secured relative to said drill housing and a radial lever arm operated from externally of said drill housing and connected to said bearing collar, clutch interface means for engaging said drill housing to said chuck jaw reciprocating means and including first and second sets of opposing teeth disposed about a common axis and about said drive shaft in facing relationship, longitudinally reciprocal means for bringing said first and second sets of teeth into and out of engagement, means for immobilizing said first set of teeth from rotation relative to said drill housing, means coupling said second set of teeth to rotate with said chuck jaw reciprocating means, biasing means urging said first and second sets of teeth apart and urging said first set of teeth to drive bearing collar toward one end of said spiral track, coupling means for moving said clutch interface means into engagement at a mechanical advantage in response to movement of said clutch actuator, wherein said lever means is coupled to said bearing collar and operable from externally of said drill housing to totate said bearing collar and overcome said biasing means to advance said bearing collar toward the opposite end of said spiral track, thereby forcing said first and second sets of teeth into mutual interengagement.

2. A reversible drill according to claim 1 further comprising torque limiting means interposed between said bearing collar and said first set of teeth.

3. In a reversible drill having a rotary drive shaft mounted in a drill housing and having a chuck engageable for rotation with said drive shaft and formed with a jaw guide, chuck jaws constrained by said jaw guides for radial advancement and retraction relative to the axis of said drive shaft, chuck jaws reciprocating means journaled relative to said jaw guide, and coupled to said chuck jaws to selectively advance and retract said chuck jaws when said chuck jaw reciprocating means and said chuck jaw guide are subjected to relative rotation in opposite directions, and manually actuatable clutch means for engaging and disengaging said chuck jaw reciprocating means relative to said drill housing to respectively prevent and allow relative rotation between said chuck jaw reciprocating means and said jaw guide, wherein said manually actuatable clutch means is arranged to apply a greater force to engage said drill housing and said chuck jaw reciprocating means together upon rotation of said drive shaft in one direction then upon rotation of said drive shaft in the opposite direction, the improvement comprising means interposed between said drill housing and said chuck jaw reciprocating means to exert a light drag tending to retard rotation of said chuck jaw reciprocating means.

4. A drill adapted to receive interchangeable bits comprising a reversible motor mounted in a drill housing and having a rotary drive shaft, a chuck mounted upon said drive shaft, said chuck being formed with a jaw guide, chuck jaws constrained by said jaw guide for radial advancement and retraction relative to the axis of said drive shaft to grip and release a drill bit, chuck jaw propelling means journaled relative to said jaw guide, and coupled to said chuck jaws to selectively advance and retract said chuck jaws when said chuck jaw propelling means and said jaw guide are subjected to relative rotation in opposite directions, and manually actuatable clutch means for moving said chuck jaw propelling means into and out of engagement with said case to respectively restrain and release said chuck jaw propelling means from rotation relative to said case, and a resilient O-ring interposed between said drill housing and said chuck jaw propelling means to exert a light drag retarding rotation of said chuck jaw propelling means.

5. In a power tool for receiving interchangeable work pieces and having a reversible motor with a rotary drive shaft mounted in a case and having a chuck mounted upon said drive shaft and formed with a jaw guide, chuck jaws constrained by said jaw guide for radial advancement and withdrawal relative to the axis of said drive shaft, and chuck jaw propulsion means journaled for rotation relative to said jaw guide, and coupled to said chuck jaws selectively advance and withdraw said chuck jaws to, respectively, grip and release a work piece, when said chuck jaw propulsion means and said jaw guide are subjected to relative rotation in opposite directions, and longitudinally movable clutch means for selectively engaging and disengaging said chuck jaw propulsion means relative to said case to respectively prevent and allow rotation of said chuck jaw propulsion means relative to said case, and means interposed between said case and said chuck jaw propulsion means to exert a light drag tending to retard rotation of said chuck jaw propelling means relative to said case.

6. In a reversible drill having a rotary drive shaft carried by a drill housing and having a chuck engageable for rotation with said drive shaft and formed with a jaw guide, chuck jaws constrained by said jaw guide for radial advancement and retracting relative to the axis of said drive shaft, chuck jaw reciprocating means journaled relative to said jaw guide, and coupled to said chuck jaws to selectively advance and retract said chuck jaws when said chuck jaws reciprocating means and said jaw guide are subjected to relative rotation in opposite directions, and manually actuatable clutch means for engaging and disengaging said chuck jaw reciprocating means relative to said drill housing to respectively prevent and allow relative rotation between said jaw guide and said chuck jaw reciprocating means including first sets of mutually engageable clutch teeth disposed about a common axis wherein said first set of clutch teeth projects toward said chuck jaw reciprocating means and is immobilized from rotation by said housing and said second set of clutch teeth faces and projects toward said first set of clutch teeth and is secured to said chuck jaw reciprocating means to move in rotation therewith, biasing means urging said clutch teeth into disengagement, and means interposed between said drill housing and said chuck jaw reciprocating means to exert a drag retarding rotation of said chuck jaw reciprocating means.