GB2258026A

GB2258026A - Two-part lock nuts.

Info

Publication number: GB2258026A
Application number: GB9115994A
Authority: GB
Inventors: Chih-Chung Chiang
Original assignee: CHIANG CHIH CHUNG
Current assignee: CHIANG CHIH CHUNG
Priority date: 1991-07-24
Filing date: 1991-07-24
Publication date: 1993-01-27
Also published as: CA2053012C; GB9115994D0; CA2053012A1

Abstract

A nut includes a first half 41 and a second half 42, the first half 41 having an internal screw thread 411 mating with the bolt 6 and an external screwthread 412 of larger pitch, and the second half 42 having two internal screwthreads 421, 422 of different radii, the narrower internal screwthread 421 being engageable with the bolt 6 and the wider internal screwthread 422 being engageable with the external screwthread 412 of the first half 41. <IMAGE>

Description

FIXING MEANS The invention relates to a set of nut and bolt, more particularly, to a set of nut and bolt which locks more tightly and securely than prior art sets.

Nuts and bolts are well known in the art. They are widely used as a fastening means. Fig. 1 shows a bolt 11 and a nut 12 of common type use to fasten two objects. The common bolt and nut can fasten two objects, but can not prevent them from loosening.

Therefore, many improvements have been added to the art. As illustrated in Fig. 2, a washer 13 is placed between the objects 20 and the nut 12 so as to help the bolt 11 and the nut 12 to engage each other more tightly. However, over time vibration of said objects still can loosen the bolt 11 and the nut 12 Fig. 3 shows another type of improved bolt and nut.

Accordingly, a plurality of throughholes 23, 24 are provided in the nut member 22 and the shank 21 of the bolt. After the shank 21 of the bolt is inserted through two objects and engaged by the nut member 22 a pin member 25 with an enlarged bottom end is inserted through the holes 23, 24 of the nut member and the shank and engaged there by bending its tips.

The pin prevents the nut and bolt from rotating with respect to each other, and thus from loosening. But a clearance still remains between the pin, the nut and the shank. Thus the bolt and the nut are therefore not fully engaged.

Fig. 4 shows another improvement which includes two nuts (12; 13). Such means can fasten two objects quite firmly together but a long period of vibration may loosen both nuts since there is no other means to prevent it from loosening.

Therefore, the main object of the present invention is to provide a nut and bolt set having at least two fastening means, so that it can fasten objects together more firmly and permanently than prior art ones.

Another object of the present invention is to provide a set of nut and bolt, the nut member having two nut pieces which provide more frictional force and tightness between them.

The nut of the present invention comprises a first half having an internal screw thread therein and an external screw thread thereon, and a second half having two different size bores, one to fit the bolt and one to fit the external screw thread of the first half. The internal screw thread of the first half is engageable with the threaded end of the bolt. The second half not only has bores of different radii, but also the two sets of internal screw threads have different screw pitch. The screw pitch of the threads in the smaller bore of the second half is the same as that of the bolt. The screw threads in the larger bore of the second nut is the same as that of external screw thread of the first half.Since there are at least two fastening means in this invention, the bolt and nut set produced accordingly can fasten two objects more firmly together and more permanently than such sets.

Other features and advantages of the present invention will become apparent in the following detailed description including drawings, all of which show a non-limiting form of the present invention, and in which: Figs. 1 to 4 show different types of bolts and nuts of the prior art.

Fig. 5 shows an exploded view of the preferred embodiment of a set of nut and bolt according to the present invention.

Figures 6 and 7 are fragmented cross sectional views of the preferred embodiment of a set of nut and bolt of the present invention in different arrangement.

Figure 8 is an enlarged view of (A) shown in Figure 6.

Figure 9 is an enlarged view of (B) shown in Figure 6.

As illustrated in Figs. 5 and 6, a bolt having a threaded end 6 passing through two objects (51, 52) and is fastened by the nut member 4. The nut member 4 includes a first half 41 and a second half 42 the first half having an internal screw thread 411 therein and an external screw thread 412 thereon.

The internal and the external screw threads are of differing screw pitches, the internal screw thread 411 of the first half 41 being engageable with threaded end 6 of the bolt.

The second half 42 has a bore with two sections of different radii. The first, narrower section has an internal screw thread 421 to fit the threaded end 6 of the bolt. The second, wider section has an internal screw thread 422 of a different screw pitch, to fit the external screw thread 412 of the first half 41 To fasten two objects (51,52) by using such a bolt and nut set, one must insert the threaded bolt 6 through said two objects and the first half nut 41 is threadably fit on the threaded bolt. Each pitch in the threaded bolt 6 has an inner side (E2) and a outer side (El) as shown in Figure 8 .On turning the head of the threaded bolt 6 in a clockwise direction, that is during tighting, the outer side (El) of the pitch of the threaded bolt 6 abuts with the thread 411 of the first half nut 41 , thereby pushing said first half 41 inward and towards the two objects.

Similarly, when the second half 42 is tightened on the first half 41 , the inner side (F) of the pitch of the threaded bolt 6 abuts with the thread 421, of the second half 42 , pushing said second half 42 inwardly with respect to the two objects, as shown in Figure 9. Thus making the fastening of the objects more secure.

Since there are three fastening arrangement in such a set of nut and bolt, the objects being fastened by the same will no doubt be far the more firm and tighter than all those in the prior art ones.

As illustrated in Fig. 7, the first half 41 and the second half 42 can be arranged in a different locking fashion but utilizing the same configuration as explained above.

Claims

CLAIMS:

1. A fixing means comprising a bolt having a threaded end and a nut member detachably engaged with said threaded end; wherein the improvement is characterized by said nut member including a first half and a second half, said first half having an internal screw thread therein and an external screw thread thereon, said internal screw thread of said first half having the same screw pitch as and being engageable with said threaded end of said bolt, said second half having a threaded bore with two sections of differing radii, a first narrower section and a second wider section, said first narrow section of said second half having the same screw pitch as and being engageable with said threaded end of said bolt, said second wider section of said second half having the same screw pitch as and being engageable with said external screw thread of said first half of said nut member.

2. A fixing means substantially as described heretofore with reference to Figures 5 to 9.