# US 12,005,556 B2 · Driving work machine

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- Number: US 12,005,556 B2
- Document ID: US12005556B2
- Status: Granted
- Kind: B2
- Application number: 17/434,323
- Filed: 2020-03-06
- Published: 2022-05-26
- Granted: 2024-06-11
- Earliest claimed: 2019-03-28
- Assignees: Koki Holdings Co., Ltd.
- Applicants: Koki Holdings Co., Ltd.
- Inventors: Kento Shiina; Takahiro Ookubo; Satoshi Abe
- Web page: https://patentgrep.com/patent/US12005556B2

## CPC

- B25D 16/006: {Mode changers; Mechanisms connected thereto}
- B25D 16/00: Portable percussive machines with superimposed rotation {, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit (combined percussion and rotary drilling adapted for earth drilling E21B6/00)}
- B25D 17/24: Damping the reaction force {(resiliently mounted handles B25D17/043; dampers in connections of hammers to backhoes E02F3/966)}
- B25D 2211/006: Parallel drill and motor spindles
- B25D 2211/061: Swash-plate actuated impulse-driving mechanisms
- B25D 2216/0023: Tools having a percussion-and-rotation mode
- B25D 2216/0038: Tools having a rotation-only mode
- B25D 2222/57: Elastomers, e.g. rubber
- B25D: PERCUSSIVE TOOLS {(percussive machines for forging B21J; hand-held drilling machines, in general B23B45/00, for wood B27C3/08; drilling machines, used for mining or quarrying, with reciprocating tool which is turned intermittently when out of contact with the working face E21B1/00)}

## Abstract

A workability of a driving work machine is improved by reduction in vibration transmitted to a housing. A driving work machine 10 includes: a cylinder 21 applying a rotational force to a tip tool; a piston 33 applying a striking force to the tip tool; a driving source generating a power; a switching part 61 making switching between at least two operational states including a rotational striking state of transmitting the power as a striking force and a rotational force to the tip tool and a rotational state of transmitting the power as the rotational force but not transmitting the power as the striking force to the tip tool; and a housing 12. The cylinder 21 includes a pushing part 46 pushing the switching part 61 rearward, the switching part 61 is able to switch an operational state of the cylinder 21 by the rearward movement caused by the pushing force of the pushing part 46, and a rubber annular member 72 serving as an anti-vibration part is arranged between the pushing part 46 and the preventing part 71.

## Claims

### Claim 1

A driving work machine comprising:
a cylinder configured to apply a rotational force to a tip tool;
a piston attached to be able to reciprocate in an axis direction inside the cylinder and configured to apply a striking force to the tip tool;
a driving source configured to generate a power for driving the cylinder and the piston;
a switching part configured to make switching between at least two operational states including a rotational striking state of transmitting the power as a striking force and a rotational force to the tip tool and a rotational state of transmitting the power as the rotational force but not transmitting the power as the striking force to the tip tool;
a housing configured to house the cylinder, the driving source and the switching part; and
a spring member arranged between the housing and the switching part and configured to urge the switching part to move forward,
wherein the cylinder includes a pushing part pushing the switching part rearward when the cylinder is moved rearward by a reactive force of the pressing of the tip tool against a workpiece,
wherein the switching part is configured to switch an operational state of the cylinder in response to the pushing part pushing the switching part,
wherein the housing includes a preventing surface configured to prevent an amount of the rearward movement of the switching part,
wherein the driving work machine further comprises an anti-vibration part in addition to the spring member, the anti-vibration part being arranged between the pushing part and the preventing surface,
wherein the anti-vibration part remains between the pushing part and preventing surface when the preventing surface prevents the rearward movement of the switching part, and
wherein the anti-vibration part is arranged between the switching part and the pushing part.

### Claim 2 (depends on 1)

The driving work machine according to claim 1 further comprising:
a driving shaft arranged inside the housing to be along the cylinder and configured to be rotationally driven by the driving source;
a motion converting part arranged in the driving shaft and configured to convert a rotational force of the driving shaft into a reciprocating force; and
a clutch attached to the driving shaft to be movable in an axis direction and configured to make switching between a state of transmitting a power of the driving shaft to the motion converting part and a state of cutting the transmission,
wherein, in the switching part, at the time of the rearward movement, the switching is made so that the power is transmitted from the driving shaft to the motion converting member, by meshing of the clutch with the motion converting part.

### Claim 3 (depends on 1)

The driving work machine according to claim 1, wherein the switching part has a plate shape extending in a direction orthogonal to the axis direction of the cylinder.

### Claim 4 (depends on 1)

The driving work machine according to claim 1, wherein the anti-vibration part is a wave washer attached to outside of the cylinder.

### Claim 5 (depends on 1)

The driving work machine according to claim 1, further comprising a washer disposed between the anti-vibration part and the switching part.

### Claim 6 (depends on 1)

The driving work machine according to claim 1, wherein the spring member is a coil spring.

### Claim 7 (depends on 1)

The driving work machine according to claim 1,
wherein the spring member has a first length in the axis direction of the cylinder,
wherein the anti-vibration part has a second length in the axis direction of the cylinder, and
wherein the first length is greater than the second length.

### Claim 8

A driving work machine comprising:
a cylinder configured to apply a rotational force to a tip tool;
a piston attached to be able to reciprocate in an axis direction inside the cylinder and configured to apply a striking force to the tip tool;
a driving source configured to generate a power for driving the cylinder and the piston;
a switching part configured to make switching between at least two operational states including a rotational striking state of transmitting the power as a striking force and a rotational force to the tip tool and a rotational state of transmitting the power as the rotational force but not transmitting the power as the striking force to the tip tool;
a housing configured to house the cylinder, the driving source and the switching part; and
a spring member arranged between the housing and the switching part and configured to urge the switching part to move forward,
wherein the cylinder includes a pushing part pushing the switching part rearward when the cylinder is moved rearward by a reactive force of the pressing of the tip tool against a workpiece,
wherein the switching part is configured to switch an operational state of the cylinder in response to the pushing part pushing the switching part,
wherein the housing includes a preventing surface configured to prevent an amount of the rearward movement of the switching part,
wherein the driving work machine further comprises an anti-vibration part in addition to the spring member, the anti-vibration part being arranged between the pushing part and the preventing surface,
wherein the anti-vibration part remains between the pushing part and preventing surface when the preventing surface prevents the rearward movement of the switching part, and
wherein the anti-vibration part is a rubber annular member fitted with an outer circumferential surface of the cylinder.

### Claim 9 (depends on 8)

The driving work machine according to claim 8, wherein the annular member includes a fitting part that fits with the cylinder to prevent relative movement in a circumferential direction with respect to the cylinder.

### Claim 10 (depends on 8)

The driving work machine according to claim 8, wherein the anti-vibration part is disposed between the pushing part and the switching part.

### Claim 11

A driving work machine comprising:
a cylinder configured to apply a rotational force to a tip tool;
a piston attached to be able to reciprocate in an axis direction inside the cylinder and configured to apply a striking force to the tip tool;
a driving source configured to generate a power for driving the cylinder and the piston;
a switching part configured to make switching between at least two operational states including a rotational striking state of transmitting the power as a striking force and a rotational force to the tip tool and a rotational state of transmitting the power as the rotational force but not transmitting the power as the striking force to the tip tool;
a housing configured to house the cylinder, the driving source and the switching part; and
a spring member arranged between the housing and the switching part and configured to urge the switching part to move forward,
wherein the cylinder includes a pushing part pushing the switching part rearward when the cylinder is moved rearward by a reactive force of the pressing of the tip tool against a workpiece,
wherein the switching part is configured to switch an operational state of the cylinder in response to the pushing part pushing the switching part,
wherein the housing includes a preventing surface configured to prevent an amount of the rearward movement of the switching part,
wherein the driving work machine further comprises an anti-vibration part in addition to the spring member, the anti-vibration part being arranged between the pushing part and the preventing surface,
wherein the anti-vibration part remains between the pushing part and preventing surface when the preventing surface prevents the rearward movement of the switching part, and
wherein the anti-vibration part is a coil spring attached to outside of the cylinder.