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US 2017/0282345 A1Published application
Bit retention assembly for rotary hammer
AssigneeMilwaukee Electric Tool Corporation
InventorsTroy C. Thorson, Jeremy R. Ebner
Life of this patent
Estimating the term…
Abstract
A rotary hammer includes a motor, a spindle coupled to the motor for receiving torque from the motor, a piston at least partially received within the spindle for reciprocation therein, and an anvil received within the spindle for reciprocation in response to reciprocation of the piston. The anvil imparts axial impacts to a tool bit in response to reciprocation of the piston. The rotary hammer also includes a bit retention assembly for securing the tool bit to the spindle.
Claims20
A rotary hammer adapted to impart axial impacts to a tool bit, the rotary hammer comprising:
- a motor;
- a spindle coupled to the motor for receiving torque from the motor;
- a piston at least partially received within the spindle for reciprocation therein;
- an anvil received within the spindle for reciprocation in response to reciprocation of the piston, the anvil imparting axial impacts to the tool bit in response to reciprocation of the piston;
- and
- a bit retention assembly for securing the tool bit to the spindle, the bit retention assembly including
- a resilient member surrounding the spindle and positioned between a first washer and a second washer,
- a sleeve at least partially surrounding the spindle, the sleeve abutting the second washer,
- a latch receivable within a slot formed in the spindle to be engageable with the tool bit, the latch is slidably biased into engagement with the tool bit, and
- a collar moveable relative to the spindle between a first position and a second position, the first position of the collar securing the tool bit to the spindle, the second position of the collar allowing the tool bit to be removed from the spindle;
- wherein in response to the anvil transitioning from an impact mode to an idle mode in which the anvil is brought to rest in the spindle, the anvil imparts a final axial impact on the tool bit, moving the latch, the sleeve, and the second washer toward the resilient member, thereby compressing the resilient member against the first washer.
8 more elements
A rotary hammer adapted to impart axial impacts to a tool bit, the rotary hammer comprising:
- a motor;
- a spindle coupled to the motor for receiving torque from the motor;
- a piston at least partially received within the spindle for reciprocation therein;
- an anvil received within the spindle for reciprocation in response to reciprocation of the piston, the anvil imparting axial impacts to the tool bit in response to reciprocation of the piston;
- and
- a bit retention assembly for securing the tool bit to the spindle, the bit retention assembly including
- a resilient member surrounding the spindle and positioned between a first washer and a second washer,
- a sleeve at least partially surrounding the spindle, the sleeve abutting the second washer,
- a dust shield coupled to the spindle for co-rotation therewith in front of the first washer,
- a front collar trapped between the second washer and the dust shield,
- a latch receivable within a slot formed in the spindle to be engageable with the tool bit, the latch is slidably biased into engagement with the tool bit, and
- a rear collar moveable relative to the spindle between a first position and a second position, the first position of the rear collar securing the tool bit to the spindle, the second position of the rear collar allowing the tool bit to be removed from the spindle;
- wherein in response to the anvil transitioning from an impact mode to an idle mode in which the anvil is brought to rest in the spindle, the anvil imparts a final axial impact on the tool bit, moving the latch, the sleeve, and the second washer toward the resilient member, thereby compressing the resilient member against the first washer.
10 more elements
A rotary hammer adapted to impart axial impacts to a tool bit, the rotary hammer comprising:
- a motor;
- a spindle coupled to the motor for receiving torque from the motor;
- a piston at least partially received within the spindle for reciprocation therein;
- an anvil received within the spindle for reciprocation in response to reciprocation of the piston, the anvil imparting axial impacts to the tool bit in response to reciprocation of the piston;
- and
- a bit retention assembly for securing the tool bit to the spindle, the bit retention assembly including
- adjacent first and second O-rings surrounding the spindle and positioned between a first washer and a second washer,
- a sleeve at least partially surrounding the spindle, the sleeve abutting the second washer,
- a dust shield coupled to the spindle for co-rotation therewith in front of the first washer,
- a front collar trapped between the second washer and the dust shield,
- a lock ring axially secured to the spindle, the first washer being abutted with the lock ring and prevented from forward movement on the spindle beyond the lock ring,
- a latch receivable within a slot formed in the spindle to be engageable with the tool bit, the latch is slidably biased into engagement with the tool bit, and
- a rear collar moveable relative to the spindle between a first position and a second position, the first position of the rear collar securing the tool bit to the spindle, the second position of the rear collar allowing the tool bit to be removed from the spindle;
- wherein in response to the anvil transitioning from an impact mode to an idle mode in which the anvil is brought to rest in the spindle, the anvil imparts a final axial impact on the tool bit, moving the latch, the sleeve, and the second washer toward the O-rings, thereby compressing the O-rings against the first washer, and
- wherein substantially no relative movement occurs between the latch, the sleeve, and the rear collar while the first and second O-rings cushion the final impact on the tool bit, thereby reducing any reaction forces exerted on the latch.
12 more elements
Dependencies are inferred from the claim text.