Claims
- 1. A method for limiting the loss of hydraulic fluid from a hydraulic cylinder located on a redi-mix concrete truck of the type wherein the discharge chute is positioned by said hydraulic cylinder coupled in circuit with a hydraulic pump by a hose, but preventing said chute from dropping upon a failure of said hose, said method consisting of providing a flow operated poppet valve in series with said lift cylinder and a hydraulic fluid line, said flow operated poppet valve having a fluid passage therethrough and seated against an internal biasing spring located in said fluid passage, said valve being normally open when hydraulic fluid flow rate is below a predetermined value, said valve closing against said internal biasing spring to block fluid flow through said poppet valve, when the flow rate in said line exceeds said predetermined value.
- 2. The method as set forth in claim 1 wherein said a flow operated poppet valve closes to block hydraulic fluid from flowing therethrough when the flow rate exceeds approximately 4 gallons per minute.
- 3. The method as set forth in claim 1 wherein closure of said flow operated poppet valve is comprised of the steps:
- (a) increasing fluid pressure on a spool having an aperture for fluid flow;
- (b) reciprocating said spool towards a conical end of a valve seat;
- (c) engaging said conical end of said valve seat with said spool aperture;
- (d) blocking said spool aperture with said conical end of said valve seal; and
- (e) preventing fluid flow through said spool aperture.
Parent Case Info
This is a divisional of copending application Ser. No. 07/674,081, now U.S. Pat. No. 5,107,679, filed on Mar. 25, 1991.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
288716 |
Nov 1915 |
DE2 |
Divisions (1)
|
Number |
Date |
Country |
Parent |
674081 |
Mar 1991 |
|