GB747021A - Improvements in and relating to roller mills, roller and breast mills or other apparatus incorporating co-operating pressure members between which substances are passed for grinding, crushing or comminuting or like purposes - Google Patents

Abstract

747,021. Reciprocating pumps. HOLMES BROS. PAINT MACHINERY, Ltd. May 27, 1954 [June 10, 1953], No. 16030/53. Addition to 743,119. Class 102(1). [Also in Group XXIX] An improvement of the invention claimed and described in the parent Specification comprises using a diaphragm 13 as a yieldable member having an area greater than that of the pump piston 8. The diaphragm is backed by a thimble 23 having a flange 33 pressed into engagement with a shoulder 34 in the casing 3 by a spring 21 adjusted by the knob 28. To permit movement of the diaphragm 13 relative to the thimble 23 during the suction stroke of the piston 8, the diaphragm is clamped between the head 39, of a bolt 38, and a flange 42 of a sleeve 37 ; the flange 42 is pressed into a groove 40 in the thimble 23 and the head 39 is pressed against the diaphragm by a spring 41 bearing against a washer carried by the bolt 38. The cylinder 6 has radial ports 9, 9a and 10, 10a communicating with the inlet and outlet 15a, 10c respectively and also connected with the pumping chamber 12 by a channel 11 ; the ports 9, 9a, 10, 10a are controlled by a groove 16 on the piston 8. In a further modification as shown in Fig. 2, the pump piston 52 is mounted in a reservoir 51 and controls an inlet port 55 in the cylinder and delivers past a non-return valve 71 to a yielding member 53 which is arranged in another cylinder 62 and is loaded by an adjustable spring 66 and controls a relief port 63. The piston 52 is actuated by a cam 56 through a rocker 56a to which is secured a member 57a in which screws a rod 57 attached to the piston. The effective stroke of the piston 52 is varied by rotating the stem 61 which is connected to the rod 57 through a pin and slot mechanism 59. Several pairs of cylinders 54, 62 may be arranged in the same reservoir. Specification 734,113, [Group XXIX], is referred to.