GB2206303A

GB2206303A - Gear-driven wrench or screwdriver

Info

Publication number: GB2206303A
Application number: GB08715248A
Authority: GB
Inventors: Tuncer Mehmet
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-29
Filing date: 1987-06-29
Publication date: 1989-01-05
Also published as: GB8715248D0

Abstract

A hand tool for imparting rotational movement to a component comprises a housing 2, a driving member 3 rotatably mounted upon the tool for manual rotation and a driven member 21 also rotatably mounted upon the tool and transmission means 4, 5 interconnecting the driving member and the driven member, the transmission means incorporating a bevel gear arrangement, the driven member 21 in turn driving a tool head 6 configured to engage the component and impart rotational movement thereto. The tool head may be a socket or a screwdriver blade. The handle 3 may be locked relative to the housing 2 so that the tool may be used like an ordinary wrench. <IMAGE>

Description

Description of Invention "lmprovements in or relating to a tool" THE PRESENT INVENTION relates to a tool and more particularly to a hand held, manually operable tool for use in imparting rotational movement to a component such as a screw, bolt or the like when such a component is to be located in or removed from a position which is not readily accessible or where space is particularly limited.

Proposals have been made previously to provide for a tool which would facilitate the location and removal of component such as screws or bolts in positions which are not readily accessible. One prior proposed screwdriver incorporated a flexible shaft which enabled the screwdriver blade to reach around corners to tighten or loosen awkwardly positioned screws. The shank of this screwdriver was constituted by a coaxial arrangement comprising a central driving core and an an outer sheath. The sheath could be bent to a selected configuration and the driving core would still rotate within the sheath. This prior proposal was, by its very nature, not of a particularly robust design and was rather awkward to use since the blade-end of the screwdriver was not supported. It has also been previously proposed to provide a screwdriver comprising a blade mounted upon a cranked shank.This design is of limited used since the entire cranked shank must be rotated in order to rotate the screwdriver blade. This obviously requires a considerable amount of space and is of little benefit where space is limited.

The present invention seeks to provide an improved tool which will facilitate the tightening and loosening of components which are located in positions which are not readily accessible.

According to the present invention there is provided a hand tool for imparting rotational movement to a component, said tool comprising a housing, a driving member rotatably mounted upon the tool for manual rotation and a driven member also rotatably mounted upon the tool and transmission means interconnecting the driving member and the driven member, said transmission means incorporating a gear arrangement, the driven member in turn driving a tool head adapted and configured to engage said component and impart rotational movement thereto.

Preferably the driving member is mounted upon the tool for rotation about a longitudinal axis of the tool and the driven member is mounted upon the tool for rotation about an axis which is not parallel to said longitudinal axis.

Conveniently said gear arrangement comprises a pair of bevel gears arranged such that the driven member rotates about an axis which is perpendicular to said longitudinal axis.

Advantageously the driving member comprises a handle provided adjacent one end of the tool, said handle being adapted to be mounted upon said transmission means.

Preferably said transmission means comprise said gear arrangement and a shaft, one of said bevel gears being mounted upon one end of the shaft and said handle being mounted upon the other end of the shaft.

Conveniently the second bevel gear is received upon the driven member.

Advantageously said driven member is provided with an internal, polygonal bore within which the tool head is received.

A magnet may be provided within said internal, polygonal bore in order to hold said tool head in positon within the bore. The magnet would also act to magnetise the tool head so that any said component made from magnetic material would be retained in engagement with the tool head when being located in an awkward position or when being removed from such a position.

Preferably the housing is of elongate, hollow, substantially cylindrical configuration.

The tool head may, for example, comprise a screwdriver or a socket to receive a nut or a bolt head.

The tool may additionally be provided with a lock arrangement which may be operated to prevent rotation of the driving member relative to the housing.

Preferably the lock arrangement comprises a dove-tail slot extending across both the driving member and the housing such that the portions of the slot provided in the driving member and the housing member may be aligned to form a continuous slot, there being a dove-tail shaped wedge provided within the slot, the wedge being movable between a first position in which the wedge extends across the junction of the driving member and the housing to prevent rotation of the driving member relative to the housing and a second position in which the wedge is received wholly within the portion of the slot provided in the housing and in which position the driving member may be rotated relative to the housing.

Conveniently the gear ratio between said bevel gears is 1:1.

The handle may have a knurled outer surface, and is conveniently a circular cross-section and is provided at one end with a diametral slot designed to receive the blade of a screwdriver.

Advantageously at least part of said housing has a knurled outer surface.

Preferably said shaft is a substantially hollow shaft.

In order that the present invention may be more readily understood and so that further features thereof may be appreciated, the invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure I is a side elevation of a tool according to the present invention; Figure 2 is a partly sectioned side elevation corresponding to Figure I; Figure 3 is an exploded, sectioned side elevation of the main components of the tool of Figures I and 2; and Figure 4 is a sectional view taken on the line IV-IV of Figure 1.

With reference to Figures I and 2 of the accompanying drawings a tool I comprises a housing 2, and a handle 3 mounted upon one end of a shaft 4, which extends into the housing, the shaft 4 being rotatable about its longitudinal axis. A pair of bevel gears 5 are provided within the housing 2, one of the bevel gears being mounted upon the shaft 4, whilst the other bevel gear is mounted upon and transmits rotary movement to a tool head receiving member 6. The handle 3 may be manually rotated, this rotation being transmitted through the shaft 4 and bevel gears 5 to the tool head receiving member 6 which in turn rotates a tool head 7 received therein.

The tool head is adapted and configured to engage and rotationally drive a component such as a screw or nut.

Dealing with each of the components in turn, the housing 2 is an elongated hollow, cylindrical component having a longitudinal axis 8. The main body of the housing 2 is of circular cross-section and is open at the right hand end as seen in Figures I and 2. At its left hand end the main body of the housing 2 is formed integrally with a spout 9 which turns through 900 and extends perpendicularly away from the longitudinal axis 8 to terminate at an open end 10. At the open end 10 the housing 2 defines a shoulder 11 and an annular groove 12 in its internal surface. An inwardly projecting, annular ridge 13 is formed integrally upon the internal surface of the housing 2 at the junction of the spout 9 with the left hand end of the main body of the housing. The housing is conveniently formed as a metal casting, although certain plastics materials may also prove suitable.

The handle 3 is elongate and of circular cross-section. The handle 3 is provided at one end with a diametrically extending slot 14 which is designed to receive the blade of a screwdriver. Any form of screwdriver blade may be received in the slot 14 and the blade may be that of a conventional screwdriver or a ratchet screwdriver. At its other end the handle 3 is formed integrally with a hexagonal projection 15. Whilst the preferred projection 15 is hexagonal, it will be appreciated that any polygonal configuration may be used. The projection 15 may be seen in Figure 3 of the drawings.

The shaft 4 is a substantially hollow, circular cross-section shaft having one open end 16 and one closed end 17. The open end 16 of the shaft 4 is provided with an internal, hexagonal bore 18 designed to tightly receive the projection 15 provided on the housing 3. The closed end 17 of the shaft 4 is formed integrally with a projection 19 similar to the hexagonal projection 15 on the handle 3. However, the projection 19 is of circular cross-section over a short length at its base, adjacent the closed end 17 of the shaft 4 whilst the remainder of the projection is hexagonal.

The bevel gears 5 comprise a first gear 20 and a second gear 21, each of which has a gear angle of 450. The gear 20 is formed with a projection 22, which extends away from the wide base of the gear and within which a hexagonal bore 23 is formed. The hexagonal bore 23 is designed such that the first gear 20 may be mounted upon the hexagonal end of the projection 19 on the shaft 4. In a similar manner the second gear 21 is formed with a projection 24 within which a hexagonal bore 25 is formed.

The tool head receiving member 6 is of circular cross-section and is formed with a projection 26 at one end. The projection 26 is of substantially the same design as the projection 19 on the shaft 4 in that it has a circular cross-section over a short length at its base adjacent the tool head receiving member 6 and is hexagonal over the remainder of its length. The second gear 21 may be mounted upon the hexagonal end of the projection 26 by way of the bore 25. At its other end the tool head receiving member 6 is formed with a polygonal recess 27, within which an appropriately shaped magnet 28 is received. The second gear 2! and the tool head receiving member 6 are retained in position within the housing 2 by means of a washer 29 which sits upon the shoulder 11 and is retained in position by a retaining clip 30.The retaining clip 30 is received within the annular groove 12.

As mentioned above, the handle 3 is adapted to be manually rotated, although a lock arrangement 3 1 is provided so that the handle 3 may be selectively connected to the housing 2 in order to prevent rotation of the handle relative to the housing. The lock arrangement 31 comprises a dovetail slot 32 formed in the outer surface of both the handle 3 and the housing 2 at the junction of the handle 3 and housing 2. A dove-tail shaped wedge 33 is slidably received within the slot 32 and may be moved between a first position in which the wedge extends across the junction between the handle 3 and the housing 2, as illustrated in Figure I so as to prevent rotation of the handle 3 relative to the housing 2 and a second position in which the wedge 33 is wholly received within the portion of the slot 32 located in the housing 2, as illustrated in Figure 2.When it is in the second position the handle 3 may be rotated relative to the housing 2.

In order to assemble the tool the first gear 20 is inserted into the open end 10 of the spout 9 and the shaft 4 is inserted into the open end of the main body of the housing 2. The projection 19 on the shaft 4 is then passed through the opening defined by the annular ridge 13 and the hexagonal end of the projection 19 is inserted into the bore 23 of the first gear 20 so that the first gear is firmly received on the projection 19 with the circular cross-sectioned base of the projection 22 on the gear 20 engaging the annular ridge 13 as illustrated in Figure 2. The closed end 17 of the shaft 4 engages the opposite side of the annular ridge 13. The ridge 13 thus acts as a bearing for the shaft 4.The projection 19 and bore 23 are designed such that the required space for the ridge 13 is left between the closed end 17 of the shaft 4 and the base of the projection 22 when the gear is mounted on the end of the projection. The space includes sufficient balance to permit free rotation of the shaft 4 and the gear 20. A washer of a low friction material may be provided between the ridge 13 and the adjacent part of the projection 19. The shaft 4 has an external diameter such that the shaft is received snugly but not tightly within the housing 2. It may be desirable to provide a low friction sleeve around the outside of the shaft 4 within the housing 2 such as a polytetrafluoroethylene sleeve. Such a sleeve would ensure that the shaft 4 rotates within the housing 2 with a minimum of frictional resistance.

The washer 29 may now be positioned over the projection 26 to be rececived adjacent the circular portion at the base of the projection 26 with an intermediate washer of low friction material, if required. The second gear 21 may now be mounted on the hexagonal portion of the projection 26 by way of the correspondingly shaped bore 25. As with the projection 19 and bore 23, the projection 26 on the tool head receiving member 6 and the bore 25 in the second gear 2 1 are designed so that there is sufficient space to receive the washer 29 when the gear is mounted on the projection, the space again including sufficient tolerance to permit free rotation of the gear 21 and the tool head receiving member.The second gear 21, which is mounted on the washer 29 and is connected to the tool head receiving member 6 may now be inserted through the open end 10 of the spout 9 so that the periphery of the washer 29 is received upon the shoulder II. This will ensure automatic alignment of the second gear 21 with the first gear 20. The retaining clip 30 is in the form of a circlip and is now compressed and located against the outwardly facing surface of the washer 29, in alignment with the groove 12. When the retaining clip is released it springs automatically into the groove 12 and then securely retains the washer 29 in position which in turn retains the second gear 2 1 and the tool head receiving member 6 in position.

The handle 3 may now be located upon the end of the housing 2 and the shaft 4 by inserting the hexagonal projection 15 into the correspondingly shaped bore 18 at the end of the shaft 4. It is intended that the projection 15 will be dimensioned so that it is received tightly within the bore 18. It may alternatively be desirable to positively secure the handle 3 upon the housing 2 by way of a retaining clip arrangement similar to the arrangement at the open end of the spout 9 so that the handle may still rotate relative to the housing. As a further alternative it would be possible to provide a ball and groove arrangement on the projection 15 and bore 18 so that the handle is retained upon the end of the shaft 4. It would, of course, be possible to provide a conventional ball and groove arrangement at all or any of the connections between the handle 3 and shaft 4, the shaft 4 and the first gear 20, or the second gear 21 and the tool head receiving member 6.

In use a tool head will be inserted into the tool head receiving member 6 and the head will be retained in position by the action of the magnet 28. The tool head may take the form of a screwdriver blade or socket spanner. The magnet will also serve to magnetise the tool head so that a screw or bolt head made from magnetic material will be retained in engagement with the tool head. This will facilitate the location and removal of the screw or bolt in a position which is difficult to reach and where the component cannot be held by hand in the usual way. When a desired tool head has been inserted into the tool head receiving member 6 the head is rotated simply by holding the housing of the tool stationary whilst the handle 3 is rotated. The handle 3 may be rotated in either direction to effect clockwise and anti-clockwise rotation of the head.It will be appreciated that the design of the tool enables screws, bolts or the like which are located in awkward positions to be more easily tightened or loosened. If the wedge 33 of the lock arrangement 31 is moved to the first position so as to lock the handle 3 against rotation relative to the housing 2 then the entire transmission path between the handle 3 and the tool head receiving member 6 is locked and the tool may be used in a manner similar to a torque wrench.

It will be appreciated that numerous modifications and alterations to the above described embodiment may be made within the scope of the present invention. It will be possible for different sizes of gears to be used so that a gear ratio other than 1:1 is achieved in order to give a mechanical advantage. It would also be possible to use gears which have an angle other than 450 so that the axis of the tool head does not extend perpendicular to the longitudinal axis 8 of the tool but at a different desired angle. This could be simply effected by providing a variety of different angled second gears 21 together with appropriately configured washers 29.

Claims

CLAIMS:

1. A hand tool for imparting rotational movement to a component, said tool comprising a housing, a driving member rotatably mounted upon the tool for manual rotation and a driven member also rotatably mounted upon the tool and transmission means interconnecting the driving member and the driven member, said transmission means incorporating a gear arrangement, the driven member in turn driving a tool head adapted and configured to engage said component and impart rotational movement thereto.

2. A tool according to claim 1, wherein the driving member is mounted upon the tool for rotation about a longitudinal axis of the tool and the driven member is mounted upon the tool for rotation about an axis which is not parallel to said longitudinal axis.

3. A tool according to claim 2, wherein said gear arrangement comprises a pair of bevel gears arranged such that the driven member rotates about an axis which is perpendicular to said longitudinal axis.

4. A tool according to any one of claims I to 3, wherein the driving member comprises a handle provided adjacent one end of the tool, said handle being mounted upon said transmission means.

5. A tool according to claim 4, wherein said transmission means comprise said gear arrangement and a shaft, one of said bevel gears being mounted upon one end of the shaft and said handle being mounted upon the other end of the shaft.

6. A tool according to claim 5, wherein the second bevel gear is received upon the driven member.

7. A tool according to any one of claims I to 6, wherein said driven member is provided with an internal, polygonal bore within which the tool head is received.

8. A tool according to claim 7, wherein a magnet is provided within said internal, polygonal bore in order to hold said tool head in positon within the bore.

9. A tool according to any one of claims I to 8, wherein the housing is of elongate, hollow, substantially cylindrical configuration.

10. A tool according to any one of the preceding claims, wherein the tool head comprises a screwdriver.

I 1. A tool according to any one of claims I to 9, wherein the tool head comprises a socket to receive a nut or a bolt head.

12. A tool according to any one of claims I to II, said tool being additionally provided with a lock arrangement which may be operated to prevent rotation of the driving member relative to the housing.

13. A tool according to claim 12, wherein said lock arrangement comprises a dove-tail slot extending across both the driving member and the housing such that the portions of the slot provided in the driving member and the housing member may be aligned to form a continuous slot, there being a dove-tail shaped wedge provided within the slot, the wedge being movable between a first position in which the wedge extends across the junction of the driving member and the housing to prevent rotation of the driving member relative to the housing and a second position in which the wedge is received wholly within the portion of the slot provided in the housing and in which position the driving member may be rotated relative to the housing.

14. A tool according to any one of claims 3 to 13, wherein the gear ratio between said bevel gears is 1:1.

15. A tool according to any one of claims 4 to 14, wherein said handle has a knurled outer surface.

16. A tool according to any one of claims 4 to 15, wherein said handle is of circular cross-section and is provided at one end with a diametral slot designed to receive the blade of a screwdriver.

17. A tool according to any one of claims I to 16, wherein at least part of said housing has a knurled outer surface.

18. A tool according to any one of claims 5 to 17, wherein said shaft is a substantially hollow shaft.

19. A tool substantially as herein described with reference to and as shown in the accompanying drawings.

20. Any novel feature or combination of features disclosed herein.