Patent GB-1276287-A (GB)
Title: Motor-driven fluid-metering device, in particular infusion pump for the operation of one or more hypodermic syringes
IPC: A61M5/145
Filed: 1970-03-20
Abstract: 1276287 Fluid-metering device BERG & BURG NV 20 March 1970 [20 March 1969] 13686/70 Heading A5R [Also in Division F1] A motor-driven fluid-metering device comprises a frame, means for mounting a fluid container, a slide member 6 connected to said container and movable in relation thereto for discharging fluid from said container, an electric motor 29, a disengagable clutch, and a means for speed reduction transmission comprising a non-slipping chain or rope drive including a first and a second wheel each rotatably mounted in said frame, a third or fourth wheel each rotatably mounted on said slide member, and a chain or rope member. The slide member 6 is slidably mounted on guide rods 5 and comprises two spaced parallel plates 7 and 8 enclosing four nylon blocks 9 adjacent the four corners thereof, each block 9 having a longitudinal bore to accept the guide rod 5, a spacer member 10 of nylon centrally arranged between the plates and two sprocket wheels 11 and 12 rotatably mounted between said plates adjacent opposite sides of the spacer 10. An elongated mounting block 13 is secured on the upper plate 8 and projects upwardly through a longitudinal slot 15 in the coverplate 2 of the housing (1), Fig. 3 (not shown), of the device. An upper support plate 17 is secured on the mounting block 13 and supports a first syringe mounting member 19, a second syringe mounting member (25), Fig. 1 (not shown) is secured to the housing coverplate 2 at the opposite end of the syringe (24), such that, movement of the slide member 6 towards the mounting member (25) discharges the fluid from the syringe (24). Against the lower side of the housing coverplate 2, the electric driving motor 29 and a reduction gear, together forming a unit, are mounted, the outgoing shaft of the gear driving a sprocket wheel 31 through a friction clutch. A sprocket wheel 38 is mounted for free rotation in a bracket 37 and a chain 39 has its one end connected to a hook 40 which is arranged in the plane of and spaced from the wheel 38. The chain 39 successively passes around the wheel 11, back to and around the wheel 38, around the wheel 31 and to the wheel 12, around this latter wheel 12 and to a spring loaded hook 42, the spring maintaining the chain under tension. Excess tension in the chain and therefore on the hook 42 cooperates a projection 47 with an actuating button of a microswitch 48 de-energising the electric motor 29. Rotation of the motor 29 in the counterclockwise direction advances the slide member 6 forwards in the direction of the motor 29. The slot 15 in the coverplate 2 is covered by a ribbon 50 secured at both ends, the ribbon passing through a groove 51 in the upper face of the mounting block 13 which groove being covered by the support plate 17. The electric motor 29 is preferably a variable speed step motor controlled by an electric oscillator, which oscillator being controlled by means of a potentiometer circuit including a plurality of separately adjustable potentiometers connected in parallel.