Hammer having piston sleeve with spiral grooves

Patent metadata

Field	Value
Publication number	US-9909666-B2
Application number	US-201414556991-A
Country	US
Kind code	B2
Filing date	Dec 1, 2014
Priority date	Dec 1, 2014
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A sleeve is disclosed for use with a hammer. The sleeve may have a generally cylindrical body with a first end and a second end. The sleeve may also have a plurality of channels spiraling at least partially around the generally cylindrical body between the first and second ends.

First claim

What is claimed is:

1. A hammer sleeve, comprising:
a generally cylindrical body having a first end and a second end; and
a plurality of channels spiraling at least partially around the generally cylindrical body between the first and second ends, wherein the plurality of channels include:
a plurality of first channels each forming a portion of a different pressure passage;
a second channel forming a portion of a drain passage; and
a third channel forming a portion of a pilot signal passage.

2. The hammer sleeve of claim 1 , wherein the plurality of channels further includes a fourth channel forming a portion of a shutoff passage.

3. The hammer sleeve of claim 2 , wherein each of the different pressure passage, signal passage, and shutoff passage spirals through about 90°.

4. The hammer sleeve of claim 3 , wherein the drain passage extends from the first end a greater distance toward the second end than each of the different pressure passage, the drain passage, and the signal passage.

5. The hammer sleeve of claim 4 , wherein the drain passage spirals through about 100-360° at a location between the second end of the generally cylindrical body and each of the different pressure passage, drain passage, and signal passage.

6. The hammer sleeve of claim 1 , wherein the plurality of first channels includes four first channels.

7. The hammer sleeve of claim 1 , wherein each of the plurality of first channels has at least one of a depth and a width greater than a depth and a width of the second, third, and fourth channels.

8. The hammer sleeve of claim 7 , wherein each of the plurality of first channels, second channel, third channel, and fourth channel has a cross-section with a curved bottom.

9. The hammer sleeve of claim 8 , wherein:
each of the plurality of first channels is fabricated using a ball end mill; and
a width of each of the plurality of first channels is about ⅔ of a diameter of the ball end mill.

10. The hammer sleeve of claim 1 , wherein:
the generally cylindrical body is hollow;
the hammer sleeve further includes a plurality of radial passages extending inward through the generally cylindrical body at the first end to a bore; and
the different pressure passage associated with each of the plurality of first channels fluidly connects at a first end with a different one of the plurality of radial passages.

11. The hammer sleeve of claim 10 , further including:
a first axial passage extending from the first end of the generally cylindrical body to a first end of the drain passage;
a second axial passage extending from the first end of the generally cylindrical body to a first end of the pilot signal passage; and
a third axial passage extending from the first end of the generally cylindrical body to a first end of the shutoff passage.

12. The hammer sleeve of claim 11 , further including:
a first annular groove formed inside the generally cylindrical body and fluidly connected to second ends of the different pressure passage associated with each of the plurality of first channels;
a second annular groove formed inside the generally cylindrical body and fluidly connected to a second end of the drain passage;
a third annular groove formed inside the generally cylindrical body and fluidly connected to a second end of the pilot signal passage; and
a fourth annular groove formed inside the generally cylindrical body and fluidly connected to a second end of the shutoff passage.

13. The hammer sleeve of claim 12 , wherein:
the first annular groove is located closer to the second end of the generally cylindrical body than the fourth annular groove;
the fourth annular groove is located closer to the second end of the generally cylindrical body than the third annular groove; and
the third annular groove is located closer to the second end of the generally cylindrical body than the second annular groove.

14. The hammer sleeve of claim 1 , further including an annular recess formed in an outer surface of the generally cylindrical body at the second end and in fluid communication with the shutoff passage.

15. An impact system, comprising:
a piston;
a sleeve having a generally cylindrical body with a first end and a second end, and a plurality of channels spiraling at least partially around the generally cylindrical body between the first and second ends, the sleeve being configured to internally receive the piston;
a sleeve liner shrink-fitted over the sleeve to form a plurality of spiraling passages at the plurality of channels;
a seal carrier connected to an end of the sleeve to form a valve enclosure; and
a valve disposed within the valve enclosure and movable to selectively direct pressurized fluid through the plurality of spiraling passages to move the piston.

16. The impact system of claim 15 , wherein:
the plurality of spiraling passages include:
a plurality of pressure passages;
a drain passage;
a pilot signal passage; and
a shutoff passage; and

each of the plurality of pressure passages, the drain passage, the signal passage, and the shutoff passage spirals through about 45-135°.

17. The impact system of claim 16 , wherein:
the drain passage extends from the first end a greater distance toward the second end than the plurality of pressure passages, the signal passage, and the shutoff passage; and
the drain passage spirals through about 360° at a location between the second end of the generally cylindrical body and each of the plurality of pressure passages, the signal passage, and the shutoff passage.

18. The impact system of claim 16 , wherein each of the plurality of spiraling passages has a cross-section with a curved bottom.

19. A hydraulic hammer, comprising:
a frame;
a bushing disposed within a first end of the frame;
a work tool reciprocatingly disposed within the bushing;
a head configured to close off a second end of the frame; and
an impact system disposed inside the second end of the frame, the impact system including:
a piston;
a sleeve having a generally cylindrical body with a first end and a second end, and a plurality of channels spiraling at least partially around the generally cylindrical body between the first and second ends, the sleeve being configured to internally receive the piston;
a sleeve liner shrink-fitted over the sleeve to form a plurality of spiraling passages at the plurality of channels;
a seal carrier connected to an end of the sleeve to form a valve enclosure; and
a valve disposed within the valve enclosure and movable to selectively direct pressurized fluid through the plurality of spiraling passaged,
wherein:
movement of fluid within the plurality of spiraling passages moves the piston against the work tool;
each of the plurality of spiraling passages spirals through about 45-135°; and
each of the plurality of spiraling passages has a cross-section with a curved bottom.

Assignees

• Caterpillar Inc

Inventors

• Moore Cody

Classifications

• B25D9/00

  Portable percussive tools with fluid-pressure drive, {i.e. driven directly by fluids}, e.g. having several percussive tool bits operated simultaneously {(portable non-percussive drilling tools driven by fluid pressure or pneumatic power B23B45/04)} · CPC title

• B25D17/06 Primary

  Hammer pistons; Anvils {; Guide-sleeves for pistons} · CPC title

• B25D2217/0019

  Guide-sleeves · CPC title

• B25D2250/231

  Sleeve details · CPC title

• F16J10/04 Primary

  Running faces; Liners · CPC title