GB2250463A

GB2250463A - Socket wrench

Info

Publication number: GB2250463A
Application number: GB9026419A
Authority: GB
Inventors: C C Frank Hsu
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-12-05
Filing date: 1990-12-05
Publication date: 1992-06-10
Anticipated expiration: 2010-12-05
Also published as: DE4101435A1; GB2250463B; GB9026419D0

Abstract

The wrench includes a pair of rollers 21 connected by an eccentric shaft 22 received in a box end 11. A C-shaped ring 30 with two arms 35, 36 is rotatably mounted on the eccentric shaft 22. A gradually narrowing space is formed between the outer surface of the eccentric shaft 22 and the inner wall 121 of the box end. A pin 50 connects the pair of rollers 21. One arm 36 of the C-shaped ring 30 is associated with the pin 50. When the handle 13 is rotated in a first direction, the arm 36 abuts the pin 50, thus preventing the arm 36 from moving into the narrowing space. When the handle 13 is rotated in the opposite direction, the arm 36 moves away from the pin 50, and the other arm 35 wedges into the narrowing space, thus driving the wrench. <IMAGE>

Description

22504,53 SOCKET WRENCH The invention relates to a wrench, more

particularly to a socket wrench having a simple construction and which is easy to manufacture.

A wrench is used for tighthening or loosening6f a nut or a screw. There exists different kinds of socket wrenches, and most of their construction are complicated.. A-socket wrench of the prior art includes a ratchet wheel retained by a pair of pawls, a handle connected to said ratchet wheel for rotating the- samer and a pair og springs to keep said pair of pawls in contact with the ratchet wheel. The ratchet wheel and the pawls construction is complicated and difficult, ther!fore the 'cost of manufacturing it is high. Besides, such socket wrench also has the following drawbacks.

(1) When the torsion force on the socket wrench is excessive, the exertion of force on the wrench is localized on a contact point in the ratchet and pawl, whidh may cause the ratchet wheel or the pawl to break apart or make cause free idling of the ratchet wheel.

(2) The components to rake up the socket wrench of the prior art are numerous, so the assembled wrench is bulky.

(3) When tighthening or loosening a nut, the pawl and the ratchet wheel are in constant moving engagement, which may in long run causes a spark, and - 2 -.

1 1, is if there should be any explosive material, such as a gas, or gasoline nearby, a fire result.

Therefore, the primary object of the present invention is to provide a socket wrench free from aforesaid drawbacks.

Another object is to provide a socket wrench with a simple construction and which is easy to manufacture.

Accordingly,--- a socket wretch of" the invention includes a handle having a box end connected thereto, said box end having a central hole and an internal wall confining the central hole. A pair of rollers is received in the central hole of the box end. The pair of rollers has an eccentric shaft connected between them so that a gradually narrowed portion is formed between the outer surface of the eccentric shaft and the internal wall surface_of the box end. A Cshaped ring has a circular notch with two arm portions, one on either side of the circular notch, which is rotatably mounted on the eccentric shaft so that- the C-shaped ring can be rotated about the eccentric shaft in the central hole of the box end. A pin member is eccentrically connected to the pair of rollers and provided adjacent to the gradually narrowed portion. One arm portion of the C-shaped ring is in contact with the pin member. Even though there remains a clearance between the internal wall surface and the C-shaped ring, the friction force between the contacting rim of the C-shaped ring and the internal wall surface, due to turning of the handle in a first direction, can urge the C-shaped ring to rotate with the internal wall surface but the C-shaped ring is stopped by the pin member. In this condition, one can not tighten or loosen a screw or a nut. The reverse operation can accomplish the work of tightening or loosening a screw of a nut.--- Other features and advantages of the present invention will become apparent in the following detailed description, including-drawingsr all of which show a non limiting form of the inventionf and of which; gig. 1 is an exploded view of a first preferred embodiment of a socket wrench according to the present invention.

Fig. 2-is a cross sectional top view of Fig. 1.

Fig. 3 is a cross sectional'view of Fig. 1 showing configuration of operation of the socket wrench according to the present invention.

Fig. 4 shows a detailed enlarged view of the socket wrench of the present inVbntion, the socket wrench being in free turning configuration.

Fig. 5 shows a detailed enlarged view of the socket wrench of the present invention, in tightening or loosening configuration.

Fig. 6 shows an exploded view of another embodiment i is 1.

of a socket wrench according to the present invention.

As shown in Fig. 1. a socket wrench (10) of the present invention includes a handle (13) having a box end. The box end (11) has a circular central hole (12) with an internal wall sutface (121) confining the central opening (12).

A rotary member (20) includes a pair of rollers (21) received in the circular central hole--(12). of the internal wall surface (121 and c6nnected by. an eccentric shaft (22). A gradually narrowed portion (25), see-in Figs. 2 and 3, is formed between the outer surface of the eccentric shaft (22) and the internal wall surface (121). A pin member (50) is eccentrically connected the pair of rollers (21) adjacent to the gradually narrowed portion in the circular central opening.. Each of the rollers (21) has a rectangular hole (23) therein. The rectangular holes are aligned with one another.

A Cshaped ring (30) has a diameter equal to that of the rollers_ (21) with an circular opening (32) therein. The C-shaped ring (30) has two arm portions (35, 36), one on either side of the circular opening (32). One arm Portion (36) of the-C-shaped ring (30) is associated with the pin member (50), The C-shaped ring is overlapped on the eccentric shaft (22) in such a way that it can be rotated about on the eccentric shaft. The periphery (33) of the C-shaped ring is is flush with the peripheries of the rollers (21) in one portion, when the arm portion (36) is in touch with the pin member. The C-shaped ring has some resiliency, when compressed inwardly, it can stretch outward from within.

Since the diameter of the pair of rollers (21) is slightly smaller than that of the circular central oppning (12). of the box end,--the pair.of rollers-can be accommodated in the opening (12) with a l ttle clearance (27) between the internal wall the pair of rollers (21) and the-C-shaped ring (30), so that the pair of rollers and.the C-shaped ring can move slightly radially within the internal wall. Thus, the pair. of rollers and the C-shaped ring'can rotate with the internal wall surface by a friction force occurs between them.

A pair of plates (40), either flat or arcuated plates, each with a central hole (41) therein. is respectively provided in each of the circular grooves (122) of the internal wall (121) of the box end, on either side of the pair of rollers, by a compression method so that the pair o plates (40) retain the pair of rollers in the internal wall surface (121). The compression method is a known art, and therefore, need not be explained here. After assemb. ly, the central holes (41) of the pair of plates (40) are aligned with the central rectangular openings (23) of the pair of i is 6 - rollers (21).

A driven shaft (60) has two ends (63) and a.rectangular shoulder (61) in the intermediate portion of the same. The driven shaft is disposed in the central rec-tangular openings (23) of the pair of rollers -and held by the rectangular shoulder (61) so that it can move slidably and axially in the rectangular openings. The two ends (63) of the driven shaft protrude from either side of the plair of plates. The pair of plates (40) also retains the driving shaft from sliding out of the7central rectangular openings of the pair. of rollers. Thus the driven shaft (60) is rotatable with the pair of rollers.

The operation of the socket wrench will be explained with reference to Figs. 2 and 3. The configuration of this wrench assembly leaves a gradually narrowed portion (25) between the wall and the eccentric shaft which stretches between the two arm portions of the C-shaped ring. The intermediate part of the narrowed portion is the narrowest. When the handle (13) of the box end is rotated in the direction shown by the arrow, see in Fig. 2, the internal wall surface, the pair of rollers and the Cshaped ring though have a little clearance between them. The-radial movement of the handle causes friction between- them, and urges the rollers and the C-shaped ring to rotate with the internal wall. Since one arm portion (35) of the C- is shaped ring (30) is stopped by the pin, C-shaped ring (30) is prevented from rotating with the internal wall (121), thereby the rollers are also stopped from rotating with the internal wall surface. This causes the internal wall surface to rotate idly, that is, the pair of rollers and the C-shaped ring are stationary with respect to the internal wall. as shown in Fig. 4.

When the handle (13).o.f the box-end is notated in the opposite direction, as indicated by.the arrow,. in Fig. 3. the friction force.between the internal wall -surface (121)r the C-shaped ring (30), and the pair of rollers, urge all' of them to rotate in the same direction. At this timel the arm portion (35) of the C-shLped ring associated with the pin (50) moves. away from the pin, the other arm portion (36) enters into the gradually narrowed portion, serving as a viedger and the friction force between the internal wall surfacei C-shaped ring and the pair rollers urges them to rotate in the same direction, see Fig. 5. The farther the handle is rotated, the farther.the.arm portion of the C-shaped ring which is associated.with the pin moves away from the pin member (50), and the. deeper the other arm portion enters into the gradually narrowed portion between the wall and the eccentr.i.c shaft, serving as a wedge, thus driving the rollers-(21)-together with the C-shaped ring and the internal wall surface. Since the driven shaft is rotatably fixed in the rollers, the i driven shaft is also driven. When securing or loosening a nut. the driven shaft engaged a socket member.

In another embodiment, the C-shaped ring (30') has set of first teeth on the periphery (331) of the same. Each of the pair of rollers (211) has a second set of teeth to compliment the first set of teeth. The two sets of teeth help to create more frictlon between the inte'rnal wall surface, the pair of rollers and the Cshaped ring. The remaining parts are the same as above, and the features are all the same as already described.

Claims

I CLAIM:

1. A wrench used with a socket member, saidwrench comprising:

a handle (13) having a box end (11) connected thereto, said box end (11) having a circular central hole (12) formed therethrough, and an internal wall surface (121). confining said circular central hole (12); 1" a pair of rollers (21) received in said central hole (12) of said box end (11), said rollers having a common axis parallel to the said central hole of said box endr and an shaft (22) connected therebetween forming a narrowed portion (25) between the outer face eccentric shaft (22) and said internal wall surface (121) of said box end (11), the intermediate portion of said gradually narrow portion being the narrowest part of the same. said pair of rollers (21) having a stop member (50) formed therebetween near said gradually narrowed portion (25), each of said pair (21) having a central rectangular opening are in alignment with one another; a substantially C-shaped ring (30) having a circular notch (32) with a first and a second arm portion (35, 36), said first and said second arm portion each being respectively disposed on either side of said circular notch (32), said C-shaped ring (30) 1 is circular pair of axis of eccentric gradually of said of rollers (23) which 1 being rotatably mounted on said eccentric shaft (22) with said notch in such a manner that said first and second arm portions surround part of the outer surface of said eccentric shaft and extend toward said gradually narrowed portion, the outer rim of said C shaped ring (30) being generally flush with the outer rims of said pair of rollers (21), said C-shaped ring (30) being rotated by friction produced by contact between said rim of said C-shaped ring (30) and said internal wall surface (121) to enable the first arm portion (35) to entex said narrowest part of said gradually narrowed portioh (25) and be wedged therein when said handle (30) is rotated about said box end (11) in a first direction and to enable said second arm portion (36) to abut said stop member (50) to prevent from movement bf said second arm portion (36) into said narrowest part of said gradually fiarrowed portion (25) when said handle (13) is rotated about said box end (11) in a second direction opposite to said first direction, so that said box end (11) can have a idling rotation with respect to said C-shaped ring (30) and said pair of rollers (21); a pair of retaining plates (40), detachably mounted to said box end (11) respectively on either side of said pair of rollers (21) to retaip said pair of rollers in said circular central bole (12) of said box end (11), each of said retaining plates (40) having a central round hole'(41) formed therein which is aligned with said central rectangular openings (23) of said pair of rollers (21)-and has a diameter. smaller than the diagonal length of said central rectangular openings (23) of said pair of rollers (21); and a driven shaft (60) having a rectangular shoulder (61) in the intermediate portion thereof, slidably and axially fitted ip said central rectangular openings (23) of said pair of rollers (21) and two ends portions (63) respectively protruding out said two central round holes (41) of said pair of retaining plates (40), so that said driven shaft (60) can be used with said socket member to rotate a screw nut when said handle (13) is rotated in said first direction.

2.. A wrench as claimed in Claim 1, wherein said stop member (50) is pin!ccentrically connected to said pair of rollers (21).

3. A wrench as claimed in Claim 1, wherein said Cshaped ring (301) has a. first set of teeth (331) on the rim of the samer and each of said pair of rollers (211) has a second set of teeth (211) to be meshed with said first- set of teeth (331) when said box end (11) is rotated in said first direction.

4. A wrench substantially as herein described with reference to the accompanying drawings.