GB2138346A

GB2138346A - Hand tools and elements for use in the manufacture thereof

Info

Publication number: GB2138346A
Application number: GB08406449A
Authority: GB
Inventors: Kenneth George Hollies
Original assignee: Whitehouse & Co William
Current assignee: Whitehouse & Co William
Priority date: 1983-03-15
Filing date: 1984-03-12
Publication date: 1984-10-24
Also published as: GB2138346B; GB8406449D0

Abstract

A wedge element (10) for use in securing a working head of a hand tool to a shaft which extends through an aperture in the head comprises a cruciform member made of an alloy which is substantially non-ductile or non-malleable so that it is substantially rigid. The cruciform member includes a first pair of arms (11) affording converging primary wedge faces (12) and a second pair of arms (15) which afford a pair of similarly converging auxiliary wedge faces (16). The wedge faces are of barbed configuration, each affording a plurality of spaced parallel shoulders (12a, 16a) and the lateral edge faces (17) of the secondary arms (15) are similarly of barbed configuration with a single shoulder (17a). <IMAGE>

Description

SPECIFICATION Hand tools and elements for use in the manufacture thereof This invention relates to hand tools of the kind comprising a working head carried at the end of a shaft which extends through an aperture in the head, and especially, but not exclusively, to tools such as hammers.

Conventionally, the head of a hammer or the like is secured to a wooden shaft by means of a wooden wedge which is driven into the end of the shaft longitudinally thereof so as to expand the latter into secure engagement with the sides of the aperture in the head in which the end of the shaft is received.

Additionally, a metal cleat or key may then be driven into the wedge and the end of the shaft, the cleat extending transversely relative to the wedge.

The use of such wooden wedges has a number of disadvantages, in that for example they are not well suited for automatic assembly, are liable to shinkage, and may split. Furthermore, when an additional cleat or key is used, it involves an additional step in the assembly of the hand tool.

According to the invention we provide a wedge element for use in securing a working head of a hand tool to a shaft which extends through an aperture in the head, said element comprising a cruciform metal member having a first pair of arms affording a pair of converging primary wedge faces and a second pair of arms which extend transversely relative to the first pair and afford a pair of auxiliary wedge faces which converge in the same direction as those of the primary wedge faces, at least one of said pairs of arms having faces of barbed configuration which present at least one shoulder towards the wider end of the wedge element.

Preferably, the second pair of arms extend from the wider end of the wedge element for only part of its length. Conveniently, the transverse width of the second pair of arms member is less than that of the primary pair of arms.

The lateral edge faces of the arms are preferably tapered so as to converge in the same direction as the wedge faces.

Preferably, the primary wedge faces are of barbed configuration. Likewise the auxiliary edge faces may also be of barbed configuration.

Additionally, at least the second pair of arms may have lateral edge faces which are barbed configuration. Preferably, in all cases, said faces may be formed with shoulders which are presented towards the wider end of the wedge element and extend across the entire width of the respective faces.

The wedge element is preferably formed as a moulding or casting of a substantially rigid, nonductile metal such as a zinc based alloy, or an aluminium alloy.

According to the invention we further provide a hand tool comprising a working head carried at the end of a shaftwhich extends through an aperture in the head, wherein the head is secured to the shaft by means of such a wedge element.

The invention will now be described by way of example with reference to the accompanying drawings which illustrate one embodiment of wedge element, and in which: Figure 1 shows the element in side elevation; Figure 2 shows the element in end elevation; and Figure 3 shows the element in plan view.

As illustrated, the wedge element comprises a one piece casting of a suitable metal alloy such as Mazak (Registered Trade mark) or an aluminium alloy, which is substantially non-ductile so that the element is rigid rather than malleable. The wedge element 10 is of cruciform shape and includes a first pair of aligned arms 11 having a pair of converging primary wedge faces 12 and tapering edge faces 13, and a second pair of integral aligned arms 15 extending perpendicularly transverse relative to the arms 11, and affording inclined, auxiliary wedge faces 16 which taper in the same direction as the wedge faces 12, but converge to a transverse edge 18 which is spaced from the edge 14 at which the faces 12 meet.

Preferably, as shown, the wider end face of the pair of arms 15 is co-planar with the wider end face of the first pair of arms 11 so as to form a single cruciform end face 19 whereby the wedge element 10 may be driven into the end of a shaft (not shown).

However, it will be appreciated that such wider end faces of the two pairs of arms need not necessarily be co-planar, and in particular the wider end face of the second pair of arms 15 could be positioned somewhat below the wider end face of the first pair of arms. As illustrated, the primary wedge faces 12 are conveniently of somewhat stepped or barbed form so as to include a series of shoulders 12a to resist withdrawal of the wedge element. Likewise, the auxiliary wedge faces 15 may be of similarly stepped or barbed form so as to afford shoulders 15a which may, as shown, be aligned with the shoulders 12a, or may be stepped in relation thereto.

As illustrated, the lateral edge faces 13 of the first pair of arms 11 converge downwardly towards the lower edge 14, and in practice the taper may correspond closely to the internal shape of an aperture in the tool head (not shown) through which the shaft (not shown) extends. In particular, the upper portions of each edge face 13 may be flared outwardly as shown relative to the lower portions for this purpose. However, the lateral ends of the second pair of arms 15 are themselves of barbed form, each being divided into at least two edge faces 17 separated by a shoulder 17a. The opposed pairs of such edge faces converge downwardly towards the lower edge 18, and collectively may be shaped to correspond closely to the internal shape of the aperture.Thus in the illustrated embodiment, the uppermost edge faces 17 are flared outwardly relative to the lowermost edge faces 17 for this purpose. In some cases the lateral ends of the second pair of arms may be divided into more than two edge faces, for example by shoulders aligned with two or more of the shoulders 15a formed on the auxiliary wedge faces 16.

Whilst the shoulders 12a, 15a and 17a all extend across the full width of the face on which they are formed, it will be appreciated that they be of localised form, as for example on individual projections or barbs protruding from the wedge face.

In use, after the shaft of a hand tool has been assembled with the working head, by insertion of the end of the shaft into an aperture in the head, the wedge element 10 can be driven into the end portion of the shaft in a single operation to secure the head in position.

To facilitate insertion of the wedge element, the edges 14 and 18 are desirably sharp, and the sections of the wedge faces immediately adjacent thereto are conveniently inclined relative to one another at a smaller acute angle than the angle between opposed pairs of faces nearer the wider end of the wedge elements.

The use of a rigid, substantially non-malleable or non-ductile material for the manufacture of the wedge element ensures that during use, the element does not tend to extrude from the end of the shaft, unlike plastic inserts which have a tendency to become loose for this reason.

Claims

1. A wedge element for use in securing a working head of a hand tool to a shaft which extends through an aperture in the head, said element comprising a cruciform metal member having a first pair of arms affording a pair of converging primary wedge faces and a second pair of arms which extend transversely relative to the first pair and afford a pair of auxiliary wedge faces which converge in the same direction as those of the primary wedge faces, at least one of said pairs of arms having faces of barbed configuration which present at least one shoulder towards the wider end of the wedge element.

2. A wedge element according to Claim 1 wherein the second pair of arms extend from the wider end of the wedge element for only part of the length of the latter.

3. A wedge element according to Claim 1 or Claim 2 wherein the transverse width of the second pair of arms is less than that of the first pair of arms.

4. A wedge element according to any one ofthe preceding claims wherein the lateral edge faces of the arms converge in the same direction as the wedge faces.

5. A wedge element according to any one of the preceding claims wherein the primary wedge faces are of barbed configuration.

6. A wedge element according to any one of the preceding claims wherein the auxiliary wedge faces are of barbed configuration.

7. A wedge element according to any one of the preceding claims wherein the second pair of arms has lateral ends which are of barbed configuration.

8. A wedge element according to any one of Claims 5 to 7 wherein said faces of barbed configuration are formed with shoulders which are presented towards the wider end of the wedge element and extend across the entire width of the respective faces.

9. A wedge element according to Claim 8 wherein said primary and auxiliary wedge faces are each formed with a plurality of said shoulders in spaced parallel relationship.

10. A hand tool comprising a working head carried at the end of a shaft which extends through an aperture in the head, wherein the head is secured to the shaft by means of a wedge element as claimed in any one of the preceding claims.

11. A wedge element substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

12. A hand tool comprising a working head carried at the end of a shaft whcih extends through an aperture in the head, wherein the head is secured to the shaft by means of a wedge element as claimed in Claim 11.

13. A hand tool having any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.