GB2080171A - Spanner - Google Patents

Abstract

The spanner 10 has opposed jaws 14, 16. Each jaw is shaped to form an abutment 24, 34 which in a driving position contacts a pair of opposite nut flats 1, 4 so that, when the spanner is rotated in a forward direction F, the abutments 24, 34 exert torque on the nut 12. The jaws 14, 16 are both recessed adjacent the abutments 24, 34 so that for reverse spanner rotation the recesses 26, 32 allow the spanner to move round the vertices of the nut until the abutments 24, 34 engage with the next pair of opposite flats 3, 6. The jaw 14 has an outer end extension 28 with an inwardly directed plane surface 30 which contacts the nut 12 on spanner reverse rotation to pull the spanner 10 towards the nut axis. This surface 30 can also be used in conjunction with a parallel surface 36 on the jaw 14 to grip the nut 12 at a different angle to the abutments 24, 34 when the space for spanner movement is restricted. <IMAGE>

Description

SPECIFICATION Spanner The invention relates to improvements in spanners.

With a conventional one-piece spanner, after each driving turn of the spanner to turn a nut, the spanner must be disengaged from the nut and repositioned before the nut can be turned any further. This problem has been overcome to a certain extent by the use of spanners incorporating ratchet mechanisms which permit the operating lever or shank of the spanner to be turned in the reverse direction while the jaws which grip the nut remain stationary.

Spanners of this kind are in the form of ring spanners or socket spanners. There are however applications where ring spanners and socket spanners cannot be used. Furthermore the ratchet mechanism is expensive and is normally used in spanners with interchangeable sockets which are not always as convenient to use as simple one-piece spanners.

A spanner can be made in accordance with the present invention which is one-piece openended and can be turned in the reverse direction relative to the nut without disengaging the spanner from the nut.

In accordance with the invention there is provided a spanner having an opening for receiving a nut, at least two abutments around the opening for contacting a pair of opposite flats on the nut, and a stop surface to engage the nut to locate the spanner in a driving position in which the abutments exert a torque to turn the nut when the spanner is turned in a driving direction, the opening being so shaped as to permit the spanner to be turned in the reverse direction relative to the nut out of the driving position to bring the abutments to a position where they can be brought into contact with the next pair of opposite flat.

In its preferred form, the spanner comprises two opposed jaws extending from a body, each jaw being shaped to form an abutment and the body having a stop surface which in a driving position contacts a nut and locates the abutments in a position in which they each contact a respective one of a pair of opposite flats on the nut at positions on opposite sides of a plane through the axial centre lines of the pair of flats, the jaw having its abutment on the side of the plane remote from the body being relieved on the side of the abutment closer to the body, and the other jaw being relieved or omitted on the side of the abutment further from the body so that in the driving position there is a space adjacent a part of each of the said pair of flats remote from the abutments, the arrangement being such that when the spanner is turned in the driving position and is turned in the driving direction the two abutments exert a torque on the nut and when the spanner is turned in a reverse direction and the body of the spanner is pushed toward the axis of the nut the spaces allow the jaws of the spanner to ride around the vertices of the nut until the abutments can be brought into engagement with the next pair of opposite flats.

A spanner of this type can be used to turn a nut through part of a revolution and can then be returned to a suitable position for starting the next driving stroke without disengaging the spanner from the nut.

A spanner in accordance with the invention will now be described in detail with reference to the accompanying drawings which show the spanner in various positions during the operation of turning a nut. In the drawings: Figure 1 shows the spanner at the start of a forward stroke when turning the nut; Figure 2 shows the spanner at the end of the forward stroke; Figure 3 shows the spanner at the start of the return stroke; Figure 4 shows the spanner during the return stroke; Figure 5 shows the spanner later during the return stroke; Figure 6 shows the spanner at the end of the return stroke; Figure 7 shows the spanner in another position where the spanner engages the nut at a different angle; and Figure 8 shows a modification of the spanner of Figs. 1 to 7.

Fig. 1 shows an open-ended one-piece spanner 10 operatively engaging a hexagonal nut 1 2 having flats indicated by reference numerals 1 to 6.

The spanner 1 0 has jaws 14 and 1 6 which are integrally connected to an elongate shank or lever 1 8 by a common body portion 20.

The body portion 20 is shaped to receive the nut 1 2 and has two surfaces 22 at an angle to one another which contact two adjacent flats 2 and 3 of the nut 12. The flat 1 of the nut 1 2 is in contact with an abutment 24 formed on the jaw 1 4 adjacent its inner end and meeting one of the surfaces 22. The jaw 1 4 beyond the abutment 24 is cut back to form a recess 26. The jaw 14 has at its end remote from the spanner body 20 and beyond the recess 26 an extension 28 which extends generally toward the other jaw 1 6 and has a plane surface 30 on its inner side which faces towards the root of the jaw 1 6.

The portion of the second jaw 1 6 immediately adjacent the surface 22 on the body 20 is relieved to form a recess 32. The jaw 1 6 at its end remote from the body 20 forms an abutment 34 which makes contact with part of the flat 4 of the nut 1 2 that is opposite the flat 1, contacted by the abutment 24 on the jaw 14. The outer end of the jaw 1 6 is shaped to form a plane surface 36 which is parallel to the surface 30 on the extension 28 of the other jaw 14.

In the operative position shown in Fig. 1, the abutments 24 and 34 on the jaws 14 and 1 6 respectively contact a pair of opposite flats 1 and 4 on the nut 1 2 at points offset in opposite directions relative to an imaginary plane through the axial centre lines of the flats 1 and 4. For this purpose the spacing between the abutments 24 and 34 must be less that the major outside dimension of the nut (ie between opposite vertices) for which the spanner is intended but greater than the minor outside dimension (ie between opposite flats).

By engaging the flats 2 and 3 the stop surfaces 22 limit the extent to which the nut can enter between the abutments 24 and 34 and correctly position them on the flats of the nut when the spanner is turned in the driving direction. In this driving position there is a gap between the flats 1 and 4 and the opposing parts of the jaws 1 4 and 1 6 adjacent the vertices of the nut 1 2 at the ends of the flats 1 and 4 remote from the abutments 24 and 34, due to the recesses 26 and 32.

When the spanner 10 is turned in a forward driving direction indicated by arrow F in Fig.

1, the abutments 24 and 34 each exert a torque on the nut 1 2 in the same sense causing the nut 1 2 to turn with the spanner 10 into the position shown in Fig. 2.

Besides acting as stops, the two surfaces 22 improve the grip of the spanner 10 on the nut 1 2 because of their contact with the flats 2 and 3 of the nut between the opposite pair of flats 1 and 4. In order to prevent damage to the vertices of the nut 12, the angle between the two surfaces 22 on the body 20 may be recessed at 40 so that there is clearance around the adjacent vertex of the nut.

Once the spanner 10 has reached the end of a driving stroke shown in Fig. 2, it can be returned to a suitable position for starting the next forward movement by turning it in the reverse direction indicated by arrow R in Fig.

3.

When the spanner 10 is turned in the reverse direction R the nut 1 2 remains stationary and its vertices at the ends of the opposite flats 1 and 4 remote from the abutments 24 and 34 move into the recess 32 in the jaw 1 6 and the recess 26 of the jaw 14 respectively. At the same time the vertex 1/2 bears on the stop surface 22 adjacent the jaw 14 causing the spanner to move away from the axis of the nut. As the reverse rotation proceeds, to allow the abutments 34 to move pass the vertex between the flats 3 and 4, the vertex between the flats 1 and 6 enters further into the recess 26 as shown in Fig. 4. In this position the flat 6 lies substantially paral lel to the surface 30.For adequate clearance the distance between jaw 1 6 in the region of the recess 32, and the outer end of the abutment 24 must be greater the dimension of the nut along an oblique line between the vertex 3/4, and the flat 1 at the point of contact with the outer end of the abutment 24. The depth of the recess 26 must be such that the distance between the bottom of the recess and the abutment 34 is greater than the major dimension of the nut.

Further rotation of the spanner 10 in the reverse direction R brings the inner surface 30 of the extension 28 of the jaw 14 into contact with the next adjacent vertex of the nut 1 2. As the extension 28 is moved around the vertex between the flats 5 and 6 the point of contact between the vertex and the extension is moved closer to the inner end of the extension, which tends to pull the spanner toward the axis of the nut drawing the abutj ment towards the next pair of opposite flats 3 and 6 (see Fig. 5). Continued rotation in the reverse direction eventually brings the spanner 10 back into its initial driving position but with the abutments 25 and 34 in contact with the next adjacent pair of opposite flats 6 and 3 of the nut 12 (see Fig. 6).

This procedure is repeated so that the spanner 10 is turned alternately in the driving and reverse directions until the nut 1 2 has been turned as far as is necessary.

When using the spanner 10 in a confined space, the angle through which the spanner can be turned may not be sufficient (ie less than 60 ) to allow the next pair of flats to be engaged upon rotation in the reverse direction.

With a conventional spanner where the jaws of the spanner are inclined to the shank this problem can be overcome by removing the spanner and turning it over. The shank or lever then extends at a different angle to the nut and the nut can be rotated until the next pair of flats can conveniently be engaged with the spanner in the original orientation.

A spanner in accordance with the invention cannot be turned over in this way in order to overcome the problems arising from using the spanner in a confined space because it does not grip the nut when turned in the reverse direction. However if the nut 1 2 is turned as far as the restricted space will allow with the spanner 10 in the driving position relative to the nut shown in Figs. 1, 2 and 6, the spanner 10 can then be turned in the reverse direction as far as the position relative to the nut shown in Fig. 4 and then partially withdrawn until the surfaces 30 and 36 engage the next pair of opposite flats on the nut in the positions as shown in Fig. 7. The inclination of the surfaces 30 and 36 to the shank 1 8 differs from the angle at which the abut ments 24 and 34 grip the nut relative to the shank, by an angle which is less than 60 , say about 30 . Thus the surfaces 30 and 36 can engage the flats of the nut when the spanner cannot be turned back far enough for the abutments 24 and 34 to be engaged. The shank can then be pivoted in the forward direction to turn the nut through approximately 30 until the spanner has been turned as far as the restricted space will allow. The spanner is then pushed further onto the nut so as to disengage the flat 3 from the surface 36 so that the spanner can pivot in the reverse direction to engage the flats with the abutments 24 and 34.

It will be appreciated that various modifications of the spanner described above are possible within the scope of the invention. For example, the part of the jaw 1 4 beyond the abutment 24 may be omitted. Such a spanner would be effective although it might require more dexterity on the part of the user. The outer pair of parallel surfaces 30 and 36 may be omitted so that there is no provision for making small turns, or they may be oriented at a different angle to the inner part of the jaws. For example instead of being inclined downwardly as shown in Fig. 1, they may be inclined upwardly. Fig. 8 shows such an arrangement with similar parts bearing the same reference numerals as in Figs. 1 to 7. Alternatively the surface 30 may be extended to provide a better grip on the nut when the surfaces 30 and 36 are used to turn the nut in the reverse direction.

Spanners that are not open-ended could be made in accordance with the invention. For example for certain applications a bridging piece could extend between the outer ends of the jaws to give them additional strength.

Claims (14)

1. A spanner comprising two opposed jaws extending from a body, each jaw being shaped to form an abutment, and the body having a stop surface which in a driving position contacts a nut and locates the abutments in a position in which they each contact a respective one of a pair of opposite flats on the nut at positions on opposite sides of a plane through the axial centre lines of the pair of flats, the jaw having its abutment on the side of the plane remote from the body being relieved on the side of the abutment closer to the body, and the other jaw being relieved or omitted on the side of the abutment further from the body so that in the driving position there is a space adjacent a part of each of the said pair of flats remote from the abutments, the arrangement being such than when the spanner is turned in the driving direction, the two abutments exert a torque on the nut when the spanner is turned in a reverse direction the and the body of the spanner is pushed towards the axis of the nut the spaces ride around the vertices of the nut until the abutments can be brought into engagement with the next pair of opposite flats.

2. A spanner according to claim 1 wherein at least one jaw is provided with an extension which, on rotation of the spanner in the reverse direction, engages the nut to move the spanner towards the axis of the nut.

3. A spanner according to claim 2 wherein the extension is provided on the jaw having its abutment on the side of the said plane closer to the body of the spanner.

4. A spanner according to claim 3 wherein the extension extends from the said one jaw generally towards the other jaw and provides a surface which faces towards the recess on the other jaw.

5. A spanner according to claim 4 wherein the gap between the extension and the other jaw is just greater than the distance between opposed flats of a nut which fits the spanner so that the nut can only pass through the gap when the flats of the nut are parallel to the gap.

6. A spanner according to claim 5 wherein the distance between the remote end of the said surface of the extension and the inner end of the recess in the said one jaw is greater than the length of a flat on a nut which fits the spanner so that the extension can engage one vertex of the nut when an adjacent vertex is in the recess adjacent the abutment.

7. A spanner according to any of the preceding claims in which each jaw has a pair of mutually opposed parallel surfaces for engaging a pair of opposite flats on the nut with the spanner at an angle to the nut different to when the abutments are in contact with the same pair of opposite flats.

8. A spanner according to claim 7 when appendant to any of claims 4 to 6 in which the said surface of the extension provides one of the said mutually opposed parallel surfaces.

9. A spanner according to any of the preceding claims wherein the body of the spanner has abutment surfaces between the jaws shaped to make contact with the adjacent flats on the nut.

1 0. A spanner according to any of the preceding claims which is adapted for use with a hexagonal nut.

11. A spanner according to any of the preceding claims in which the jaws are fixed relative to one another.

1 2. A spanner according to any of the previous claims in which the jaws are openended.

1 3. A spanner substantially as hereinbefore described with reference to the accompanying drawings.

14. A spanner having an opening for receiving a nut and at least two abutments around the opening for contacting a pair of opposite flats on the nut and a stop surface to engage the nut to locate the spanner in a driving position in which the abutments exert a torque to turn the nut when the spanner is turned in the driving direction, the opening being so shaped as to permit the spanner to be turned in the reverse direction relative to the nut out of the driving position to bring the abutments to a position where they can be brought into contact with the next pair of opposite flat.