GB2137545A - Screwdriver spanner or socket set - Google Patents

Abstract

A handle 2 is adapted to slidably receive a shaft 7 thereby to align a first toothed clutch face 72 on the shaft with a second toothed clutch face 41 in the handle. In this way pressure applied to urge the handle further on to the shaft causes the toothed clutch faces to couple together so that rotation of the handle produces rotation of the shaft. A spring 5 causes the two faces to decouple when the pressure applied to the handle is removed thus allowing free rotation of the handle with respect to the stem. The handle can include at least one slot 11 closed by a disc 13, the slot being adapted to receive drive heads for use with the screwdriver or the like. <IMAGE>

Description

SPECIFICATION Screwdriver or the like This invention relates to screwdrivers or the like.

Known screwdrivers have one screwdriver blade thus making it difficult to use the screwdriver with screws and screw nuts different in size to the ideal size for the particular screwdriver blade. Working with an incorrectly sized blade can consume a lot of time and labour and even cause damage to the elbow or other joints of a user.

Other screwdrivers can have either a variety of screwdriver blades or can be extended with sleeve attachments, thereby increasing the scope of application of the screwdriver. However these all fail to permit both tightening up and loosening of a given object screw or screw nut by means of only rotational operation, they require the reversing of the blade position of a screwdriver or a plug-in spanner.

Although this major inconvenience has been overcome by some kinds of known semi-automatic screwdrivers they require adjustment flaps in order to adapt to a change in rotation direction. Furthermore their structure includes ratchet wheels which produce significant noise when in action, a nuisance for both the user and a third party, and in addition they require rather complicated structural design with a consequently greater risk of break-down.

They therefore lack economic justification.

It is an obect of the present invention to provide a screwdriver convenient in use, substantially free of noise in use, simple in construction, low in production costs and with a low failure rate in use.

According to one aspect of the invention there is provided an improvement to regular semi-automatic screwdrivers Titled Clutch-set semi-automatic screwdriver, comprising chiefly: (1) an in-shell clutch: executed as a hollow-set cylinder whereof the exterior rim is profiled into a crown-set dentally serrated periphery plus a spring; (2) a counter-sunk clutch: executed as a capped hollow-set cylinder whereof the cap top is profiled to take the form of a uniformly arrayed dental, wheely crest plus an in-cap projectile meant to exert thrusting stress against the spring.

According to another aspect of the invention there is provided a screwdriver or the like comprising a handle adapted to slidably receive a shaft thereby to align a first clutch face provided on the shaft with a second clutch face provided in the handle so that pressure applies to urge the handle further on to the shaft causes said clutch faces to couple together so that rotation of the handle produces rotation of the shaft, the device including biasing means to urge said faces to decouple when said pressure is removed. Preferably the clutch faces comprise an annular array of teeth which are urged to decouple when said pressure is removed by a spring disposed between the faces.The handle can comprise two sections to permit assembly of the device, one of said halves having the second clutch face provided thereon, and the handle can include at least one slot closed by a cover, the slot being adapted to receive drive heads used with the screwdriver or the like.

Examples of the present invention are now described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a screwdriver in accordance with the present invention; Figure 2 illustrates the screwdriver of Figure 1 having its clutch arangement in the uncoupled position; Figure 3 is a cross-sectional view of the screwdriverin Figure 2 along line A-A; Figure 4 illustrates the screwdriver of Figure 1 having its clutch arrangement in the coupled position; Figure 5 is an exploded view of the screwdriver shown in Figure 1.

Referring to the drawings, a screwdriver comprises a shell grip 1 divided into a fore section 2 and a rear section 3. A clutch 4 is attached to the interior of the rear section 3 and is shaped like a cylinder and has a toothed clutch facing 41. The clutch can be integrated with the interior of the rear section 3 by means of injection moulding techniques. The toothed clutch facing 41 surrounds a hollow centre 42 provided in the clutch and there is disposed therein a spring 5. The front half 2 of the shell grip 1 contains a further clutch 7 structured like a capped hollow cylinder. The end of the clutch 7 that faces clutch 4 includes a tubular stub 6 surrounded by a clutch facing in the form of an array of teeth 72.The tubular stub 6 projects ahead of the teeth 72 and has a diameter smaller than the hollow centre 42 so that the front edge 73 of the tubular stub can enter the aperture 42 and contact the spring 5.

One end of a screwdriver stem 8 is formed with a hollow cylinder 81 for slidable coupling with any one of a number of screwdriver heads 12. The head can be chosen according to the application of the screwdriver. The opposite end of the stem is formed into an oblong core 82 which is passed through a central hole 132 of a disc enclosure 13 and a central hole 21 of the front section 2 of the shell grip 1. The oblong core is slidably located with a central hole 71 provided in the further clutch 7 and the disc enclosure is located with the front fore section 2.

In use when the screwdriver is required to tighten an object screw pressure is exerted on the rear section in a direction towards the stem in order to bring the clutch arrangement of facing 72 and 4 into engagement, as shown in Figure 4. Then pressure to rotate the shell grip in, say, a clockwise direction is transmitted to the stem. When pressure on the rear section is released the spring 5 acts to bring the clutch arrangement out of engagement so that facing 72 and 4 are disengaged, as shown in Figure 2. In this latter state the clutch arrangement is decoupled and the rear section can be rotated freely counter-clockwise and then the manual operation of applying pressure to the rear section can be repeated again in order to further achieve tightening of the object screw.

To loosen a secured screw, pressure is exerted on the rear section in a direction to urge the handle on to the stem, to bring clutch facings 4 and 72 into contact, as shown in Figure 2. Pressure to rotate the shell grip in a counter-clockwise direction loosens the object screw. By releasing the grip to decouple the clutch arrangement the rear section can be rotated in a clockwise direction and then the manual operation repeated in orderto further loosen the object screw.

The shell grip handle 1 also includes a number of straight holes 11 provided in the front section 2 coaxially with the screwdriver stem 8 in order to accommodate a number of the screwdriver heads 12. The interior end of the holes 11 is sealed up and the other end thereof is covered by the disc enclosure 13. The disc enclosure 13 is provided with a hole 131 of a size identical to or a little bit larger than that of the straight hole 11 and the disc is arranged to be capable of rotation. If the hole 131 is not aligned with any of the straight holes 11 then the screwdriver heads 12 are securely stored. When the disc is turned so that hole 131 is aligned with a given straight hole 11 in which a required screwdriver head is stored then the screwdriver can slide out and be mounted at the front of the screwdriver stem for use. The external contour of the disc and grip handle can be formed with a rough surface of straight set serrations to facilitate holding by the hand.

It will be apparent that although a screwdriver is described the invention extends to applications wherein rotation is required, for example spanners and socket sets.

Claims (11)

1. A screwdriver or the like comprising a handle adapted to slidably receive a shaft thereby to align a first clutch face provided on the shaft with a second clutch provided in the handle so that pressure applies to urge the handle further on to the shaft causes said clutch faces to couple together so that rotation of the handle produces rotation of the shaft, the device including biasing means to urge said faces to decouple when said pressure is removed.

2. A screwdriver or the like as claimed in claim 1 wherein a biasing means comprises a spring disposed between said faces.

3. A screwdriver or the like as claimed in claim 1 or 2 wherein said faces comprise an annular array of teeth.

4. A screwdriver or the like as claimed in any preceding claim wherein the handle comprises two sections to permit assembly of the device, one of said handles having the second clutch face provided thereon.

5. A screwdriver or the like as claimed in any preceding claim wherein the handle includes at least one slot closed by a cover, the slot being adapted to receive drive heads used with the screwdriver or the like.

6. A screwdriver or the like as claimed in any preceding claim wherein the shaft comprises a stem connected to a clutch carrying the first clutch face.

7. An improvement to regular semi-automatic screwdrivers Titled Clutch-set semi-automatical screwdriver, comprising chiefly: (1) an in-shell clutch: executed as a hollow-set cylinder whereof the exterior rim is profiled into a crown-set dentally serrated periphery plus a spring; (2) a counter-sunk clutch: executed as a capped hollow-set cylinder whereof the cap top is profiled to take the form of a uniformly arrayed dental, wheely crest plus an in-cap projectile meant to exert thrusting stress against the spring.

8. The clutch-set semi-automatical screwdriver according to claim 7, of which the in-shell clutch as covered in (1) is structured so that the bottom thereof is in fact an integrated part of the tail portion of the grip shell produced through molded ejections, that a spring is placed in a hole central to the stem thereof, as annexed to the exposed face of the projectile in the cap of the counter-sunk clutch, from which face a pressure will turn to exert against the spring.

9. The clutch-set semi-automatical screwdriver according to claim 7, of which the counter-sunk clutch as covered in (2) is structured such that the face of the in-cap projectile will be set against the spring whereas the hollow section on the other end of the cylinder-clutch is coupled to the counter-sunk screwdriver head to discharge the function of transmissions.

10. The assemblage of the in-shell clutch, the spring, the counter-sunk clutch fitted according to claim 2 and claim 9, characteristic in that by exerting force to set the grip to rotation in one direction, the counter-sunk screwdriver head will react to bear pressure to impose upon the counter-sunk clutch, whereupon the spring will be compressed to set both clutches to full engagements to the effect that the counter-sunk screwdriver head will be transmitted accordingly; that to follow that, if the pressure imposed heretofore is released by rotation in the reverse direction, then the spring will react to push the counter-sunk clutch so that both clutches will become disengaged to result in an idle running of the grip handle without bringing the counter-sunk screwdriver head into transmission so that by holding the grip in one hand to perform a reciprocally run repeated manipulation which means a charging of pressure in one direction and discharging ofthe same in the reverse direction in turns it will achieve in the tightening or else loosening of an object screw that is being worked upon.

11. A screwdriver of the like substantially as herein described with reference to the accompanying drawings.