Hydraulic hammer having variable stroke control

Patent metadata

Field	Value
Publication number	US-2016199969-A1
Application number	US-201514594542-A
Country	US
Kind code	A1
Filing date	Jan 12, 2015
Priority date	Jan 12, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

A variable stroke control system for a hydraulic hammer is disclosed. The variable stroke control system may include a valve configured to selectively adjust a stroke length of a piston associated with the hydraulic hammer based on the direction of flow of pressurized fluid within the hydraulic hammer.

First claim

What is claimed is:

1 . A variable stroke control system for a hydraulic hammer, comprising:
a valve configured to selectively adjust a stroke length of a piston associated with the hydraulic hammer based on the direction of flow of pressurized fluid within the hydraulic hammer.

2 . The variable stroke control system of claim 1 , wherein the valve is configured to cause the stroke length of the piston to decrease when the pressurized fluid flows within the hydraulic hammer in a first direction.

3 . The variable stroke control system of claim 1 , wherein the valve is configured to cause the stroke length of the piston to increase when the pressurized fluid flows within the hydraulic hammer in a second direction.

4 . The variable stroke control system of claim 1 , further including a routing assembly having a pump and a return tank, and configured to direct pressurized fluid within the hydraulic hammer in a first direction or in a second direction.

5 . The variable stroke control system of claim 4 , further including an operator control valve configured to receive an operator input indicative of a desire to direct the pressurized fluid in the first direction or in the second direction.

6 . The variable stroke control system of claim 1 , wherein the valve is a first valve, and the variable stroke control system further includes a second valve configured to control a transition timing between upward and downward movements of the piston.

7 . The variable stroke control system of claim 6 , further including:
an inlet groove formed around the piston and configured to receive pressurized fluid; an outlet groove formed around the piston and configured to discharge the pressurized fluid; a first switch groove formed around the piston in between the inlet groove and the outlet groove and configured to switch a valve position of the second valve; and a second switch groove formed around the piston in between the inlet groove and the first switch groove and configured to accelerate a transition from an upward movement of the piston to a downward movement of the piston.

8 . The variable stroke control system of claim 7 , wherein the second switch groove is in fluid communication with the second valve when the pressurized fluid flows within the hydraulic hammer in a first direction.

9 . The variable stroke control system of claim 7 , wherein the second switch groove is not in fluid communication with the second valve when the pressurized fluid flows within the hydraulic hammer in a second direction.

10 . The variable stroke control system of claim 7 , wherein a distance between the first switch groove and the second switch groove affects a difference in length between a shorter stroke of the piston and a longer stroke of the piston.

11 . A variable stroke control system for a hydraulic hammer, comprising:
an inlet groove formed around a piston associated with the hydraulic hammer and configured to receive pressurized fluid; an outlet groove formed around the piston and configured to discharge the pressurized fluid; a first valve configured to control a transition timing between upward and downward movements of the piston; a first switch groove formed around the piston in between the inlet groove and the outlet groove and configured to switch a valve position of the first valve; a second switch groove formed around the piston in between the inlet groove and the first switching groove and configured to accelerate a transition from an upward movement of the piston to a downward movement of the piston; and a second valve configured to selectively adjust a stroke length of the piston based on whether the first valve is in fluid communication with the second switch groove.

12 . The variable stroke control system of claim 11 , wherein the second valve is configured to allow fluid communication between the first valve and the second switch groove when the pressurized fluid flows within the hydraulic hammer in a first direction.

13 . The variable stroke control system of claim 12 , wherein the fluid communication between the first valve and the second switch groove causes the stroke length of the piston to decrease.

14 . The variable stroke control system of claim 11 , wherein the second valve is configured to block fluid communication between the first valve and the second switch groove when the pressurized fluid flows within the hydraulic hammer in a second direction.

15 . The variable stroke control system of claim 14 , wherein no fluid communication between the first valve and the second switch groove causes the stroke length of the piston to increase.

16 . The variable stroke control system of claim 11 , wherein a distance between the first switch groove and the second switch groove affects a difference in length between a shorter stroke of the piston and a longer stroke of the piston.

17 . The variable stroke control system of claim 16 , wherein increasing the distance between the first switch groove and the second switch groove increases the difference in length between the shorter stroke of the piston and the longer stroke of the piston.

18 . The variable stroke control system of claim 16 , wherein decreasing the distance between the first switch groove and the second switch groove decreases the difference in length between the shorter stroke of the piston and the longer stroke of the piston.

19 . The variable stroke control system of claim 11 , further including an operator control valve configured to receive an operator input indicative of a desire to direct the pressurized fluid in a first direction or in a second direction.

20 . A hydraulic hammer system, comprising:
a piston; a routing assembly having a pump and a return tank, and configured to direct pressurized fluid within the hydraulic hammer in a first direction or in a second direction; an inlet groove formed around the piston and configured to receive the pressurized fluid from the pump; an outlet groove formed around the piston and configured to discharge the pressurized fluid to the return tank; a first valve configured to control a transition timing between upward and downward movements of the piston; a first switch groove formed around the piston in between the inlet groove and the outlet groove and configured to switch a valve position of the first valve; a second switch groove formed around the piston in between the inlet groove and the first switching groove and configured to accelerate a transition from an upward movement of the piston to a downward movement of the piston; and a second valve configured to selectively adjust a stroke length of the piston based on the direction of flow of the pressurized fluid.

Assignees

• Caterpillar Inc

Inventors

• Moore Cody

Classifications

• B25D9/26 Primary

  Control devices for adjusting the stroke of the piston or the force or frequency of impact thereof {(control systems adapted for earth drilling E21B44/00)} · CPC title

• F15B1/02

  Installations or systems with accumulators · CPC title

• B25D9/18

  involving a piston-type slide valve · CPC title

• B25D9/145

  for hydraulically actuated hammers having an accumulator · CPC title

• F15B11/08 Primary

  with only one servomotor · CPC title