Patent GB-911274-A (GB)
Title: Latching device
Inventor: ROGERS GERALD LEE
IPC: F16L37/60
Filed: 1961-05-01
Abstract: 911,274. Latch fastenings. STILE-CRAFT MANUFACTURERS Inc. May 1, 1961, No. 15682/61. Class 44. [Also in Group XXVIII] A latching device for a pair of relatively movable members comprises a latch plug 54 having a catch abutment 79 and adapted to be mounted on one member, a latching unit including a housing 62 and adapted to be mounted on the other member, a latch arm 71, pivotally mounted on the housing, a plunger 65 slidably mounted in the housing and engageable with the latch plug upon insertion of the plug into the latching unit, spring means 77 interconnecting the plunger and latch arm, a latch element 83 carried by the latch arm and adapted to engage the abutment 79 when the plug is inserted and a stop 75 engageable with the latch arm upon initial depression of the plunger by the latch plug, the mounting of the latch arm in the housing permitting a translatory movement of the latch arm to disengage the stop from the latch arm so that the spring means can move the latch arm and latch element to release the plug when desired and the arrangement and construction having such that the stop and latch arm are re-engaged after withdrawal of the plug. As shown the two relatively movable members are a hose terminal fitting 11 and supply terminal assembly 10 for fluid or suction lines. The hose terminal fitting 11 includes in addition to the latch plug 54 a tubular valve plug 53 and the supply terminal assembly 10 mounts the latching unit and includes a socket member 21 to receive the valve plug 53. When the hose terminal fitting 11 is engaged with the supply terminal assembly 10 the latch plug 54 is inserted into a bushing 85 of housing 62 and the valve plug is inserted into a passage 37 of socket member 21. As valve plug 53 is moved inwardly it depresses a valve element 41 rearwardly against the action of a spring 44 and when it is fully inserted the forward end 42 of valve element 41 clears a reduced portion 40 of e passage 37 and places the valve plug in communication with a bore 17 and supply pipe 27 through an opening 56. To achieve this the movement of the valve element 41 is used to open a valve element 35 against the pressure of a spring 36. The insertion of the latch plug into the bushing 85 depresses the plunger 65 rearwardly against the action of the spring 77 and this causes the latch element 83, which as shown is a pin, to be cammed along slots 82 in the latch arm against the pressure of a spring 84 by shoulders 86 on the plunger so that the pin 83 rides over the front end of the plunger and the latch plug until, when the plunger 65 is fully depressed, the pin 83 moves into engagement with the catch abutment 79 on the latch plug. During the rearward movement of the plunger the stop 75 engages a ledge 76 on the latch arm to prevent the latch arm from being moved about pivot pin 74 by the spring 77 as the plunger is depressed. Upon manual release of the hose fitting 11, the fitting and hence the plug 54, move slightly outwardly under the action of springs 44 and 77. As the latch plug moves to such position the catch abutment 79 engages latch pin 83 and moves latch arm 71 outwardly against the pressure of spring 77, this movement being possible since in addition to the pivot pin 74 which is connected to the housing 62, the pivot means includes L-shaped slots 73 in the arm. The movement of the latch arm causes the ledge 76 to clear the stop 75 and this allows the latch arm to move slightly so that the pivot pin 74 is located in the vertical legs of the slot 73 so that re-engagement of the ledge 76 with the stop 75 cannot take place. Pivoting of the latch arm about the pin 74 is prevented by engagement of the latch pin 83 with the catch abutment 79 which has a sloping surface. To release the hose fitting 11 the fitting is pushed inwardly and this allows the latch pin 83 to move out of engagement with the abutment 79 by the action of spring 77 pivoting the latch arm 71 about pin 74. The hose fitting can then be removed and as the latch plug 54 is withdrawn the plunger moves forwardly under the action of spring 77 so that the means 81, which is a shoulder on the plunger, engages the rear of latch arm 71 and cams the arm so that the pin 74 is moved into the other legs of slots 73. The spring 77 can then move the latch arm rearwardly so that the ledge 76 becomes engaged with stop 75 which is its initial position. During the removal of the hose fitting the valve element 41 moves forwardly to cut off the supply of air or suction by engagement with the reduced portion of passage 37 and the valve element 35, which is a secondary valve, is also released to close a second valve port.