Claims
- 1. Apparatus for controlling a dozer blade mounted on a pair of push arms comprising:
- a pair of pitch rams connected respectively between said blade and said push arms for parallel actuation;
- a diverter-combiner valve having an input port and two output ports in parallel communication respectively with first ends of said rams for assuring equal rates of fluid flow to and from said first ends of said rams, said output ports of said diverter-combiner valve being capable of communicating with each other through said valve;
- a pitch control valve having a first outlet communicating with said diverter-combiner valve input port and a second outlet in simultaneous fluid communication with the parallel second ends of said pitch rams and disposed to selectively supply pressure to either outlet while draining fluid from the other outlet; and
- pilot operated check valves connected between the diverter-combiner valve output ports and said first ends of said rams and between said pitch valve outlet and second ends of said rams and disposed to prevent fluid communication between said first ends of said rams and also between said second ends of said rams in the absence of pressure from said pitch valve;
- a tilt ram connected between one of said pitch rams and its push arm; and
- a tilt valve connected to selectively direct pressure to one end of said tilt ram while simultaneously exhausting fluid from the other end.
- 2. The invention according to claim 1, and further comprising:
- a regenerative check valve arranged to permit fluid exhausted from the other end of said tilt ram during lowering of the adjacent corner of said blade to supplement the flow directed to said one end thereof.
- 3. The invention according to claims 1 or 3 and further comprising:
- a lift ram connected to said blade for raising and lowering thereof; and
- a lift valve for selectively directing pressure to one end of said lift ram while simultaneously exhausting fluid from the other end thereof.
- 4. The invention according to claim 3 and further comprising:
- a regeneration valve moveable in response to lowering of said blade to a position in which exhausted fluid may supplement flow from said lift valve when the pressure of said exhausted fluid is higher.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 06/125,397, filed Feb. 27, 1980, now abandoned.
This application is related to the subject matter in co-pending U.S. patent applications Ser. No. 124,875 now U.S. Pat. No. 4,352,398, filed by R. K. Schantz and entitled CONTROL FOR PITCH AND TILT OF DOZER BLADE, and Ser. No. 125,398 now abandoned and a continuation filed Dec. 10, 1982, U.S. Ser. No. 448,170, filed by S. C. Kirkham, R. K. Schantz and L. F. Kramer and entitled HYDRAULIC CONTROL FOR PITCH AND TILT OF DOZER BLADE. All three applications were filed on the same day and are assigned to a common assignee.
US Referenced Citations (15)
Continuations (1)
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Number |
Date |
Country |
Parent |
125397 |
Feb 1980 |
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