GB2035868A

GB2035868A - Torque tool with rack and pinion operated jaws

Info

Publication number: GB2035868A
Application number: GB7937647A
Authority: GB
Original assignee: Engineering Components Ltd
Current assignee: Engineering Components Ltd
Priority date: 1978-11-10
Filing date: 1979-10-31
Publication date: 1980-06-25
Also published as: GB2035868B

Abstract

A tool for gripping an end of a cylindrical filter unit has a pair of arms (1,2) with jaws (3,4) each arm being attached to a base plate (5,6) and the two base plates are held together and moveable by means of a bolt or stud (15) passing through them carrying a pinion (13) which engages racks (7,8) in the base plates. Alternatively the pinion is carried by one plate to engage a rack of the other. Movement of the pinion in the direction required to unscrew a filter first causes the arms to close to grip the filter. Further movement will then unscrew the filter. <IMAGE>

Description

SPECIFICATION Improved filter-removal tool This invention relates to a tool to be applied to an end of a cylindrical workpiece, such as a throw-away oil filter, and to facilitate gripping such a workpiece to enable a turning torque to be applied to it.

It is common practice in the motor industry to use as filter for engine lubricating oil a unit which consists of an externally cylindrical container, having oil filtering means therein, and threaded at one end for mounting on a seating on the engine. Such units are designed to be replaced and thrown away at regular service intervals. A difficulty frequently encountered with these units is that they are difficult to grip when wishing to unscrew them, their surface being generally oily. The container construction is flimsy, as befits a throw-away item, and therefore does not lend itself to provision of an integral hexagon for removal purposes.

U.S. Patent Specification No. 3,119,290 describes a tool whose purpose is to grip the end of the oil filter element by means of a pair of rigid metal arms, and provide a means by which the element can be unscrewed using an ordinary spanner. The particular tool described in this specification functions by the use of a cam to move its arms and suffers from the difficulty that its range of movement is restricted, there being a wide variation in diameters in the filter elements in common use, and the cam will lock out at the limit of movement of the tool, thus limiting its grip potential.

According to the present invention a tool for gripping an end portion of a substantially cylindrical filter unit comprises a pair of arms extending in co-operating relationship, opposed jaw portions on the arms, and a pair of base members in at least partly superimposed relation, one arm extending from one end of one member, the other arm extending from the opposite end of the other member, the base members being relatively movable, to change the distance between the arms, by means of a rack and pinion mechanism, a rack being provided on at least one member as one side of a hole in said member and the pinion being actuable by means of an actuating means located on the opposite side of said superimposed base members from said arms, the edges of the base members each having perpendicular walls reinforcing said base members and acting as guides when the base members are superimposed, the arrangement of the rack and pinion being such that in use rotation of the actuating means in the direction required to unscrew a filter unit moves the arms towards each other to grip the unit in the jaws, further rotation of the actuating means serving to unscrew the unit.

One embodiment of the invention is illustrated, by way of example only, in the accompanying drawing which is an exploded perspective view of a filter removal tool. The tool consists of a pair of arms 1 and 2 the edges of which are turned through 90 to form jaw portions 3 and 4. Arm 1 is attached to one end of base member 5, arm 2 being on the opposite end of base member 6. Each base member has a slot in it, one side of which is toothed to form a rack, the rack 7 being on the opposite side of the slot in base member 5 to the location of the rack 8 in the slot in base member 6. Thus when the two base members are assembled in superimposed relation the two racks 7 and 8 face each other.

The edges of both base members form perpendicular walls 9 and 10 which act as guides when the members are superimposed.

The walls 9 on base member 6 are also provided with portions which are deeper and are turned over into flanges 11 which are parallel to the base member 6 and serve to prevent tilting of base member 5 relative to base member 6 when the two are superimposed.

When the tool is assembled together a pinion 1 3 engages the two racks 7 and 8, the pinion being mounted on a shaft 1 5 and maintained in place in engagement with the racks by means of a pair of collars 1 2 and 14 on the shaft 1 5 which sandwich the base members and pinion. An actuating member in the form of a hexagonal head 1 6 is provided on the end of the shaft 1 5 which is on the side of the base members opposite to the arms.

In operation the tool is placed over the end of a filter unit with the unit between the arms 1 and 2. The hexagonal head 1 6 is turned anti-clockwise thus causing the base members 5 and 6 to slide over each other by means of racks 7 and 8 moved by the pinion 13, and moving the jaws 3 and 4 on the arms 1 and 2 into engagement with the filter unit. Further counter clockwise rotation of the head 1 6 tightens the grip of the jaws 3 and 4 until the unit begins to move with the tool and become unscrewed from its seat. The length of the jaws 3 and 4 is such that they will grip all the sizes of filters on which the tool is for use without the filter case contacting the arms 1 and 2 between the jaws.

In the embodiment described above the two base members are both provided with racks and the pinion floats between them. A rack could be provided on one bbse member only if desired, the pinion then being rotatably mounted on the other.

Other variations of the arrangement specifically described will also be apparent to those skilled in the art without departing from the scope of the invention.

The rack and pinion mechanism used in the tool gives it a wide range of movement which enables a compact tool to be designed which will deal with most of the sizes of filter units in common use

Claims

1. A tool for gripping an end portion of a substantially cylindrical filter unit which com prises a pair of arms extending in co-operating relationship, opposed jaw portions on the arms, and a pair of base members in at least partly superimposed relation, one arm extend ing from one end of one member, the other arm extending from the opposite end of the other member, the base members being relatively moveable, to change the distance between the arms, by means of a rack and pinion mechanism, a rack being provided on at least one member as one side of a hole in said member, and the pinion being actuable by means of an actuating means located on the opposite side of said superimposed base members from said arms, the edges of the base members each having perpendicular walls reinforcing said base members and acting as guides when the base members are superimposed, the arrangement of the rack and pinion being such that in use rotation of the actuating means in the direction required to unscrew a filter unit moves the arms towards each other to grip the unit in the jaws, further rotation of the- actuating means serving to unscrew the unit.

2. A tool according to claim 1 in which a rack is provided in both these members, the pinion floating between said base members mounted on a retaining bolt which carries said actuating means and serves to hold together the two base members.

3 A tool according to claim 1 or 2 in which the jaw portions on the arms are the turned-up edges of the arms and extend far enough away from the arms to grip all diameters of filter which fit into the tool without the filter contacting the arms.

4. A tool according to any one of the preceding claims in which the base member adjacent to the actuating means has a portion of its edges turned over to form flanges which will enclose the edges of the other base member to form guides to maintain the base members in parallel planes.

5. A tool according to any one of the preceding claims in which each base member with its associated arm and jaw portions is made from a single sheet of metal.

6. A tool substantially as described herein with reference to, and as illustrated in, the accompanying drawing.