Hydraulic coupler with pin retention system for coupling an attachment to a work machine

摘要

A coupler for coupling an attachment to an excavator having a latching member for retaining a rear pin of the attachment and a blocking member for retaining the front pin of the attachment. A hydraulic actuator and spring are provided for holding the latching and blocking members in their closed states. In the event of a failure of the actuator, the spring, the latching member and the blocking member together hold the front and rear pins in their respective recesses to allow continued operation of the coupler, while allowing the pins to move with respect to the coupler to create a rattling movement that can indicate to the operator that a failure has occurred.

主权项

1. A coupler for coupling with an attachment, the coupler comprising a body having a first and second spaced-apart recesses for receiving respective pins of said attachment; a latching member movable into and out of a latching state in which it is capable of retaining the respective attachment pin in said first recess; actuating means for actuating said latching member into and out of said latching state; a blocking member movable into and out of a blocking state in which it is capable of retaining the respective attachment pin in said second recess; actuating means for actuating said blocking member into and out of said blocking state; resilient biasing means for resiliently biasing said latching member into its latching state; and resilient biasing means for resiliently biasing said blocking member into its blocking state, wherein said latching member has a primary pin-engaging surface, a free end and a pin-retaining portion between the primary pin-engaging surface and the free end, wherein said coupler is operable in a normal mode in which said primary pin-engaging surface of said latching member is engaged with the respective attachment pin to hold said respective pin in a first position in said respective recess under the action of said actuating means for actuating said latching member, and upon failure of said actuating means for actuating said latching member the coupler is operable in a failure mode in which said pin-retaining portion of said latching member is engaged with said respective attachment pin to hold said respective pin in a second position, different from said first position, with respect to said respective recess, and wherein in said failure mode said coupler adopts an equilibrium state in which the biasing force of said resilient biasing means for resiliently biasing said latching member balances with the un-latching force caused by the weight of the attachment acting on said latching member through said respective pin in said pin-retaining portion to cause the latching member to hold said respective pin in said second position.