GB2319000A - Hammer with split head - Google Patents

Abstract

A split hammer head (10 Fig 5) comprises two co-operating head portions 12 having correspondingly recessed opposed faces 14 which together provide a bore 16 for receiving an end part (52 Fig 3) of a handle (50 Fig 3) and head end sockets 18, 20 each internally formed 36 for retentively receiving an inter-changeable insert 80 providing an exterior work contacting or striking face 82. In use the head portions 12 are secured about the handle end part (52 Fig 3) by a releasable bolt (34 Fig 5) which passes through the handle end part to positively secure the head assembly (10 Fig 5) to the handle (50 Fig 3). The recessed faces 14 may provide a cavity 22 for accommodating a relatively movable anti-recoil mass such as lead shot 44 in a container 42. The bore 16 and handle end part (52 Fig 3) may be of non-circular e.g., rectangular, cross-section to prevent turning of the head assembly (10 Fig 5) relative to the handle (50 Fig 3). Their taper engagement 26 provides a firm fit and prevents relative end movement.

Description

HAMMER This invention relates to a safety hammer of the kind which has interchangeable head inserts.

Hammers may be used for a variety of applications. However, there are many tasks which require the use of hammers with heads of various shapes and with faces of various materials.

It is expensive to provide a person with individual hammers with different heads for the various tasks which he may be required to perform. Furthermore, it is undesirable for the person to have to carry a multitude of hammers between tasks.

Hammers with interchangeable head inserts were developed to reduce the number of hammers but again it is necessary to carry a number of inserts to be able to perform a range of tasks. The inserts are of different shapes and materials, and are lockably engaged and disengaged with the hammer head to allow one hammer to be used for more than one task.

However, the range of inserts which are capable of being used with any of the currently available hammer heads is limited. It is therefore still necessary for a worker to have at least three hammers to be able to perform a full range of tasks.

It is an object of the present invention to provide an improved hammer.

Accordingly, the present invention provides a split head assembly for a hammer comprising: two co-operating head portions; wherein said head portions have correspondingly recessed opposed faces which together provide: a first recess for receiving an end part of a handle; and at least one second recess internally formed for retentively receiving an interchangeable insert providing an exterior work contacting or striking face; and wherein said head portions, in use, are firmly and locatingly secured about the handle end part by releasable transverse securing means which passes through the handle end part and secures positively the head assembly to the handle yet on release or slackening permits the head portions to be separated for insert replacement.

The invention is further characterised by the correspondingly recessed opposed faces of the two head portions providing a further recess or cavity for accommodating a relatively movable ant-recoil mass such as lead shot within a container.

The present invention is further described hereinafter, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation ofone portion of a head of a preferred form of hammer according to the present invention; Figure 2 is an end elevation of the head portion of Figure 1 as seen in the direction of arrow A of Figure 1; Figure 3 is a side elevation of a handle for the hammer; Figure 4 is a further side elevation of the handle of Figure 3 as seen in the direction of arrow BofFigure3; Figure 5 is a side elevation of the head of the preferred form of hammer assembled on the handle of Figures 3 and 4; Figure 6 is a longitudinal section through the head portion of Figure 1 along the line 6-6 of Figure 1; and Figure 7 is a longitudinal section through an insert for the hammer.

Referring to the drawings, a preferred form of safety hammer according to the present invention has a head assembly 10 fitted to a handle 50, the head having two inserts 80, only one of which is shown.

The head 10 is generally "T"-shaped and has a body formed by two mirror image portions or halves 12 which abut or closely face one another by faces 14 which lie in a dividing plane.

Figure 1 is a side elevation of one half 12 showing the recessed face 14 whilst Figure 2 is an end elevation.

Although the two portions 12 are mirror images of one another for ease of manufacture, it will be appreciated that this need not be the case provided the two portions are designed such that they co-operate to form the body of the head.

When the two halves 12 are assembled together they define several complete recesses 16, 18, 20 and 22. The first recess 16 is a bore having a lower portion 24 and an upper portion 26.

The bore is of generally rectangular cross-section with the lower portion 24 being of generally fixed cross-section along its axial length whilst the upper portion 26 tapers outwardly along its axial length to receive a correspondingly shaped end part 52 ofthe handle 50.

The co-operating shapes of the bore 16 and the handle portion 52 ensure that the head is held securely on the handle when the two halves 12 are secured together about the handle portion 52.

When the two halves 12 of the head body are located on the handle 50 the head body is secured in position by means of a bolt 34 (Figure 5) which locates through openings 30 in the side wall of the bore 16, and passes through a through-bore 60 in the end part 52 of the handle 50. The head body is thus positively held without play on the handle.

As is seen in Figure 1, the head body is generally T-shaped and, when assembled, the recesses or sockets 18 and 20 are formed at each end 32 ofthe head body. These sockets are axially aligned and are split by the dividing plane of the head body. Each socket 18, 20 is generally circular in cross-section (although any suitable cross-section may be used) and has an enlarged diameter base portion 36 with a reduced diameter mouth 38. At its narrowest portion 40, each socket 18, 20 has a number of co-axial grooves 46 which are conveniently uniformly spaced apart and which serve to grip an insert and resist rotation of the insert within the socket.

The fourth recess or cavity 22 in the head body is generally cylindrical in shape and is again split by the dividing plane. It receives a correspondingly shaped cylindrical container 42 which contains material of high density such as lead shot 44. Once the two halves 12 are secured together they securely retain the container 42 against movement and the lead shot 44 provides the non-recoil or dead blow effect for the hammer in use.

Although the illustrated container 42 is removable, this is not essential. The lead shot or other high density material may be permanently secured within both halves of the hammer head body.

Each half 12 ofthe head body is conveniently made from a single piece ofmetal, for example steel.

Referring now to the insert, Figure 7 is a longitudinal section through a preferred form of insert 80 which is of circular cross-section. The insert 80 has a generally planar workface 82 at one end and its other end region 84 is shaped so as to fit securely within the socket 18 or 20 of the head body. The insert is conveniently made of any suitable material such as plastics material, nylon, rubber, hide or copper or may be constructed from a combination ofmaterials, for example metal with a hide or fabric covering. In addition, although the face 82 is shown as generally planar, other shaped faces may be provided.

When the head 10 is assembled, the insert 80 is held securely in the socket 18 or 20 by the grooved narrow portion 40 which is received by a neck 86 of the insert and prevents rotation of the insert 80 in the socket.

A combination of two different inserts 80 may be used with the same head 10.

The handle is conveniently made of glass fibre reinforced plastics material, and can be of different shapes and lengths to suit differing capacity hammers. The handle may also be provided with a rubber grip.

As will be appreciated, replacement of the insert 80 or the fitting of a different type of insert is accomplished simply and easily by loosening the retaining bolt 34 passing through the head to allow removal of the insert and its replacement. Since each insert is retained by the co-operating shape of its end portion 84 and the socket 18, 20, only one hammer head body need be provided for any number of differently sized or shaped inserts 80.

Claims (10)

1. A split head assembly for a hammer comprising: two co-operating head portions; wherein said head portions have correspondingly recessed opposed faces which together provide: a first recess for receiving an end part of a handle; and at least one second recess internally formed for retentively receiving an interchangeable insert providing an exterior work contacting or striking face; and wherein said head portions, in use, are firmly and locatingly secured about the handle end part by releasable transverse securing means which passes through the handle end part and secures positively the head assembly to the handle yet on release or slackening permits the head portions to be separated for insert replacement.

2. A split head assembly according to Claim 1 wherein the correspondingly recessed opposed faces of the two head portions provide a further recess for accommodating a relatively movable anti-recoil mass.

3. A split head assembly according to Claim 2 wherein the further recess which accommodates the relatively movable anti-recoil mass receives the latter in a container.

4. A split head assembly according to Claim 1,2 or 3 wherein the recess and the handle end part received therein are of corresponding non-circular cross section to resist turning of the head assembly relative to the handle.

5. A split head assembly according to any of the preceding claims wherein the recess and handle end part received therein are at least partly ofcorresponding taper form to provide their firm locating interfitting engagement and resist end movement of the head assembly relative to the handle.

6. A split head assembly according to any of the preceding claims wherein the or each second recess which receives an interchangeable insert is of enlarged internal form relative to a mouth for retentively receiving a correspondingly enlarged portion of the insert.

7. A split head assembly according to Claim 6 wherein: the or each second recess which receives an interchangeable insert has a narrow portion between the enlarged internal form and the mouth; and said narrow portion engages about a neck of the insert.

8. A split head assembly according to Claim 7 wherein the narrow portion is formed such as by co-axial grooving to grip the neck of the insert to resist movement or rotation of the insert relative to the recess.

9. A hammer having a split head assembly according to any of the preceding claims.

10. A hammer set including a split head assembly therefor according to any of claims 1 to 8 wherein interchangeable inserts ofvarious suitable materials or combination ofmaterials and/or of differing exterior work contacting or striking face formation are provided to meet different working requirements.