GB211314A - Improvements in air pumps - Google Patents

Abstract

211,314. Dunlop Rubber Co., Ltd., and Macbeth, C. Jan. 16. 1923. Actuating pumps by foot power.-An air pump consists of two vertical cylinders on a common base, with unconnected pistons actuated by direct foot pressure, the cylinders having connections to a common delivery outlet. The pumps may be operated independently and alternately or simultaneously by one foot or both. The pistons are returned by springs; a pivoted foot plate may be swung out at right angles to the base to support the pump. The cylinders 1 are screwed into the base plate 2; alternatively, the base plate may be cast around them. A delivery box 3 is provided on the plate and has check valves 4 controlling the passages from the pumps. A bridge plate 5 fits under flanges 6 formed on the cylinders and is screwed to piston rod guides 13, which are thus held in place in the cylinder ends. Latches on the bridge plate may hold the pedals when fully depressed, to diminish the space occupied. Double cone springs 12 are interposed between the upturned flanges 14 of the piston guides and the pedal plates 9. A plate 15 pivoted to the base plate may be swung out to support the pump, into a position where a spring-loaded ball 16, Fig. 4, housed in the base plate engages a recess in the plate 15. A gauge 17 is secured to the delivery box by soldering or brazing, or by a rubber washer 18 pressed into sealing contact with the walls by a gland nut 19. An aperture in the bridge plate allows the gauge to be read by the operator.