467,638. Hydraulic presses. UNITED SHOE MACHINERY CORPORATION. Dec. 18, 1935, No. 35047. Convention date, Dec. 19, 1934. [Class 69 (ii)] [Also in Group XVI] A machine adapted for applying pressure to boot or shoe parts, for example, in impressing markings on boot or shoe bottoms, comprises two opposed work-engaging members 16, 18, Fig. 1, by poweroperated approach of which the work is pressed, together with a hydraulic device associated with one of said members which device is, at the conclusion of a movement of said member to effect a preliminary engagement with the work, made effective to resist movement of the member away from the work during subsequent relative approach of the members caused by means other than the hydraulic device, until the pressure on the work creates such pressure of the liquid in the device as to operate a relief valve. The marking head 18 is fixed to a cylinder 76 slidable in the machine frame 10, and having slidably-mounted within it, with a tight fit, a plunger 78 closed at the top by a cap 98 which bears against a part 140, Fig. 2, of the pressure-applying arm 130. Extending through the plunger 78 and pushed upwardly by a spring 106 is a rod 104 carrying a ball-valve 102 at its lower end adapted to co-operate with a seat at the lower end of a hollow valve-member 82 normally seating on a flange 80 on the plunger under the action of a spring 84. A sleeve 90 screwed into the plunger 78 and rotatable by means of a geared shaft 96 and hand wheel serves to adjust the pressure of the spring 84. The cylinder and plunger contain oil or similar fluid, and are kept raised by springs 138, 144, Fig. 1, respectively, the latter acting on a pivoted lever 28 connected to the head 18. The pressure arm 130 is connected by a link 120 to an eccentric strap 118 on a shaft 62 driven through a one-revolution clutch normally held inoperative by the engagement of a projection 58 on a clutch sleeve 60 with one arm 56 of a bell-crank lever 54 held in such position by springs 64, 72. A notched arm 48, normally engaging an abutment 52 on the lever 54 is pivoted to a lever 44 having its other end situated between stops 42, 148 on a rod 24 attached to a treadle lever 20 and passing through the lever 28 attached to the head 18, a yielding connection being provided therewith by means of a spring 36 and stops 32, 34. When the treadle 20 is depressed, during the initial part of its movement the spring 36 is compressed and depresses the arm 28 to cause the cylinder 76 and head 18 to be lowered into contact with the workpiece, this movement being independent of the plunger 78 due to the fact that the ball valve 102 is held open by engagement of the rod 104 with an adjustable stop 110 when the plunger is in its raised position. Further movement of the treadle causes the stops 42 to engage the lever 44 and so move the arm 56 from engagement with the projection 60 thus throwing in the clutch. As downward movement of the arm 130 now takes place, the ball valve 102 closes due to the release of the rod 104 from the stop 110, and the plunger 78 and cylinder 76 move together as a unit to apply pressure to the workpiece. When this pressure reaches a certain value determined by the spring 84, the valve 82 opens under the pressure of the fluid between the members 76, 78. On continued rotation of the shaft 62, the springs 138, 144 return the members 76, 78 to normal position, the stop 110 opening the valve 102 in such position. Subsequent to its release from the arm 56, the projection 58 strikes a projection 70 on the lever 48 so as to move it out of engagement with the abutment 52, thus allowing the arm 56 to move back into clutch-releasing position and moving the lever 48 into a position where it is inoperative until the treadle has been released. Specification 28661/03, [Class 100], is referred to.