GB2362594A

GB2362594A - Box spanner

Info

Publication number: GB2362594A
Application number: GB0028509A
Authority: GB
Inventors: David Ling; Hsien-Chung Tuan-Mu
Original assignee: Hand Tool Design Corp
Current assignee: Hand Tool Design Corp
Priority date: 2000-05-22
Filing date: 2000-11-23
Publication date: 2001-11-28
Also published as: DE10059699A1; GB0028509D0; TW418745U

Abstract

A spanner includes a box end that has an inner periphery including a first open end and a second open end. The second open end includes an annular ledge 21 formed thereon. The annular ledge is integrally formed with a portion of the inner periphery that defines the second open end. The inner periphery of the spanner may be polygonal or may include a plurality of teeth each having a tip 121. The annular ledge has a radial length greater than a height of the teeth tips. The spanner may be a ratchet spanner.

Description

2362594 Spainner with Prevention of Disengagement of Fasteners

Background of the Invention

1, Field-of the Inventio

The present invention relates to a spanner that may prevent disengagement of fasteners during operation.

2. Descri12tion of the Related A Fig. 1 of the drawings illustrates a conventional spanner with a box end. When in use, a nut (or bolt head) is held in the box end of the spanner, as shown in Fig. 2. Nevertheless, as shown in Figs. 3 and 4, the nut tends to move out of the box end such that the outer periphery of the nut is apt to be damaged and thus cannot be used anymore. Fig. 5 illustrates a box end 12' of a conventional spanner 1 V. A plurality of holes 13' are defined in the box end 12'. A tube or cylinder 20' is inserted into each hole 13' with an end of the cylinder 20' extended into a space defined in the box end 12'. When in use, the cylinders 20' together prevent a nut or bolt head 15' from passing through the box end 12', as shown in Fig. 6. Nevertheless, drilling holes 13' reduces strength of the box end 12' and thus adversely affects the torque-bearing capacity of the spanner. In addition, the assembly procedure becomes troublesome, as additional hole- drilling procedure and cylinder-mounting procedure are required. A proposal to solve the disengagement problem of fasteners is to form a plurality of protrusions or knurls on the inner periphery of the box end, yet the manufacture is difficult to achieve and not compatible with current manufacturing methods for spanners.

Fig. 7 illustrates a box end 35' of another conventional spanner, wherein two diametrically aligned holes 34' are defined in the box end 35' for receiving two ends 30' of a substantially -shape stop 32'. The stop 32' extended in a space 36' defined by the box end 35' prevents a nut or bolt head from passing through the box end 35'. Nevertheless, drilling holes 34' reduces strength of the box end 35' and thus adversely affects the torque-bearing capacity of the spanner. In addition, the assembly procedure becomes troublesome, as additional hole-drilling procedure and stop-mounting procedure are required.

1 Fig. 8 illustrates a box end 7' of a further conventional spanner 5, wherein the box end 7' includes an annular recessed portion 6' for receiving a C-shape bearing plate 2', and a ringlike cover 3' is in threading engagement with the recessed portion 6' for positioning the Cshape bearing plate 2'. Nevertheless, manufacture for the box end becomes troublesome for it is necessary to forin the recessed portion 6' that includes threading in a periphery thereof. Assembly procedure also becomes troublesome for the additional bearing plate 2' and ringlike cover 3'. The manufacture cost for the spanner is thus increased.

Summary of the Invention

It is a primary object of the present invention to provide a spanner that may prevent disengagement of fasteners during operation.

A spanner in accordance with the present invention has a box end. The box end comprises an inner periphery including a first open end and a second open end. The second open end includes an annular ledge formed thereon.

The annular ledge is integrally formed with a portion of the inner periphery that defines the second open end. The inner periphery of the spanner may be polygonal. In an embodiment of the invention, the inner periphery of the spanner includes a plurality of teeth each having a tip. The annular ledge has a radial length greater that a height of the teeth tips.

The present invention also relates to a method for manufacturing a box end of a spanner that has a through-hole in the box end. The method comprises cutting the box end by a cutter from a first end of the through- hole of the box end to a second end of the through-hole of the box end yet not passing through the second end of the through-hole, thereby forming an inner periphery with an annular ledge in the box end.

Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Draw' g

Fig. 1 is a perspective view of a box end of a conventional spanner.

2 Fig. 2 is a perspective view illustrating use of the conventional spanner in Fig. 1.

Fig. 3 is a top view of the conventional spanner in Fig. 2.

Fig. 4 is a sectional view taken alone line 4-4 in Fig. 3.

Fig. 5 is a top view, partly sectioned, of a box end of another conventional spanner.

Fig. 6 is a sectional view illustrating operation of the spanner in Fig. 5.

Fig. 7 is a top view, partly sectioned, of a box end of a ftirther conventional spanner.

Fig. 8 is an exploded perspective view of a box end of still another conventional spanner.

Fig. 9 is a perspective view of a first embodiment of a box end of a spanner in accordance with the present invention.

Fig. 10 is a perspective view similar to Fig. 9, illustrating operation of the spanner in accordance with the present invention.

Fig. I I is a top view of the spanner in Fig. 10.

Fig. 12 is a sectional view taken along line 12-12 in Fig. 11.

Fig. 13 is a perspective view of a second embodiment of the box end of the spanner in accordance with the present invention.

Fig. 14 is a perspective view of a third embodiment of the box end of the spanner in accordance with the present invention.

Fig. 15 is a perspective view of a fourth embodiment of the box end of the spanner in accordance with the present invention.

Fig. 16 is a perspective view of a fifth embodiment of the box end of the spanner in accordance with the present invention.

Detailed Description of the Preferred Embodiments

Referring to Figs. 9 through 16 and initially to Fig. 9, a first embodiment of a spanner 10 in accordance with the present invention generally includes a box end 11 with an inner periphery 12 for driving a fastener, such as a nut or bolt head. In this embodiment, the inner periphery 12 of the box end 12 has a plurality of teeth each having a tip 12 1. The box end 11 3 may further include a switch piece 15 for changing ratcheting direction for driving fasteners, such as nuts, bolt heads, etc. Namely, the spanner may be a ratchet-type spanner allowing a change in the ratcheting direction. Of course, the spanner may include two box ends or of any other type having a box end with a structure disclosed in this specification.

The box end 12 defines a space 12a having a first open end 13 and a second open end 14. The second open end 14 includes a disengagement- preventing means 20 provided thereon. In this embodiment, the disengagement-preventing means 20 is an annular ledge 21 formed on the second open end 14. The annular ledge 21 has a radial length greater that a height of the teeth tips 121.

Fig. 10 shows operation of the spanner for driving a nut 40. As illustrated in Figs. 11 and 12, the nut 40 bears against the annular ledge 21 during loosening or tightening. Namely, the nut 40 is stopped by the annular ledge 21. Accordingly, disengagement of the nut 40 during operation is prevented.

The annular ledge 21 is formed simultaneously with the teeth of the inner periphery 12. More specifically, when forming the inner periphery 12 in a box end having a through-hole, the cutter (not shown) for forming the teeth of the inner periphery 12 is moved from a first end of the throughhole to a second end of the through-hole. Nevertheless, the cutter is not moved beyond the second open end 14. Namely, the cutter is withdrawn from the first end instead of moving beyond the second end, thereby leaving a thin, annular ledge 21. Formation of the annular ledge 21 is convenient. Additional processing procedures and assembly procedures are not required. Such a manufacturing method is completely compatible with currently used methods for manufacturing spanner box ends.

Fig. 13 illustrates a second embodiment of the box end of the spanner 10, wherein the box end 50 includes an inner periphery defined by a plurality of alternately disposed concave sections 51 and convex sections 52. Fig. 14 illustrates a third embodiment of the box end of the spanner 10, wherein the box end 60 includes a rectangular inner periphery 61 defined by four faces 62. Fig. 15 illustrates a fourth embodiment of the box end of the spanner 10, 4 wherein the box end 70 includes a polygonal inner periphery 71 defined by eight faces 62. Fig. 16 illustrates a fifth embodiment of the box end of the spanner 10, wherein the box end 80 includes a polygonal inner periphery 81 defined by six faces 82, each two adjacent faces 82 having a groove 83 therebetween. It is noted that in each embodiment a disengagementpreventing means in the form of an annular ledge is formed.

According to the above description, it is appreciated that the annular ledge prevents disengagement of the nut or bolt head yet allows passage of the bolt shank. Formation of the annular ledge is convenient and compatible with current methods for manufacturing spanner box ends. Additional elements or modifications to the box ends are not required.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.

Claims

What is claimed is:

1. A spanner having a box end, the box end comprising an inner periphery including a first open end and a second open end, the second open end including an annular ledge formed thereon.

2. The spanner as claimed in claim 1, wherein the annular ledge is integrally formed with a portion of the inner periphery that defines the second open end.

3. The spanner as claimed in claim 1, wherein the spanner includes two box ends.

4. The spanner as claimed in claim 1, wherein the spanner is a ratchet-type spanner.

5. The spanner as claimed in claim 1, wherein the spanner is a ratchettype spanner allowing a change in a ratcheting direction thereof.

6. The spanner as claimed in claim 1, wherein the inner periphery of the spanner is polygonal.

7. The spanner as claimed in claim 1, wherein the inner periphery of the spanner includes a plurality of teeth each having a tip.

8. The spanner as claimed in claim 7, wherein the annular ledge has a radial length greater that a height of the teeth tips.

9. A method for manufacturing a box end of a spanner, the box end having a through-hole, the method comprising cutting the box end by a cutter from a first end of the through-hole of the box end to a second end of the through-hole of the box end yet not passing through the second end of the through-hole, thereby forming an inner periphery with an annular ledge in the box end.

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