Patent GB-1467397-A (GB)
Title: Plumbing tool for use in cleaning out drains conduits and the like
IPC: B08B9/02
Filed: 1974-03-27
Abstract: 1467397 Device for feeding a plumber's snake L F IRWIN [trading as MARCO PRODUCTS CO] 27 March 1974 [30 Nov 1973] 13530/74 Heading F2N  A tool for cleaning drains by insertion of a coiled wire plumber's snake 16 from a housing 14, both of which are rotated by a reversible motor 18, includes an automatic feed control 24 able to tolerate snake distortions and to vary the feed rate according to the degree of obstruction encountered in the drain and which comprises a rotatable feed mechanism 36 movable into and out of engagement with the snake and able to feed it axially of itself, said movement being in response to movement of an engaging mechanism 74 having a control 77, an adjustable spring 102 tending to force the engaging mechanism into contact with the feed mechanism. The feed mechanism consists of several rollers 46 having specially-formed helical bands to engage the coils of the snake, the rollers being free to rotate on axles 48 attached to segments 40, the axles being inclined by a few degrees to the snake axis. The ends of the axles protrude through slots (68) in a circular support plate 42 and are secured to it by their head portions 52 for sliding movement radially of the snake sufficient to allow the rollers to engage and disengage the snake. The support plate is free to rotate in a casing 30 because of a bearing 62. Springs 70 tend to keep the segments 40 separate and the rollers disengaged. The rotating snake is fed by the engaged rollers if the feed mechanism is prevented from rotating relative to the casing 30, the direction of feed depending on the direction of rotation of the snake. A stop means 116 is used for this purpose and consists of a spring- loaded lever 118 pivoted at 120 and operating a piston 122 so that it may be brought into braking engagement with the feed mechanism 36. When the stop means is not engaged the feed means rotates with the snake without feeding it. The engaging mechanism 74 consists of a conical component 78 that matches the conical shape of the segments 40 and is rotatably attached to the loading ring 82 by a bearing 86. The loading ring has a spring-loaded control means 77 and set screw 97 providing diametrically opposite each other through arced slots 92 and 99 in the cover 30 so that sideways movement of the handle 88 of the control means causes the loading ring to move axially of the snake, hence causing the feed mechanism to engage or disengage the snake because of the interaction of the conical component 78 and the segments 40. When the snake is engaged the spring 102 provides the force to keep the rollers in contact with it. In the event of an obstruction being encountered in the drain or in the snake itself forces are automatically generated which tend to move the rollers radially away from the snake. Depending on the spring 102 and the forces generated the rollers slip to some extent and the feed rate is reduced, possibly to zero. The force exerted by the spring 102 on the loading ring 82 is adjustable by rotation of a ring 104 to which one end of the spring 102 is attached, the other being fixed to the loading ring 82. Any one of the holes 110 in a flange 106 of the ring 104 may be located on a dowel 112 to retain the desired position of the ring.