US3789707A

US3789707A - Two speed wrench

Info

Publication number: US3789707A
Application number: US00299762A
Authority: US
Inventors: J Belknap
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-24
Filing date: 1972-10-24
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05

Abstract

A wrench having a first handle in which a rotatable drive member surrounded by a drive ratchet is journalled, and a second handle is pivotally connected to the first handle. A linkage assembly including a drive pawl connects the second handle to the ratchet so as to cause rotation of the drive member at a faster rate than the rate of pivotal movement of the second handle relative to the first handle. The linkage also connects the second handle to the drive member so as to lock the drive member with respect to the first handle, when the second handle is held in fixed relation to the first handle, so that the two handles and drive member may be turned in unison.

Description

United States Patent [.191 Belknap Feb. 5, 11974 Two SPEED WRENCH 76] Inventor: James R. Belknap, 1188 Coast Village Rd., Santa Barbara, Calif. 93103 '22 Filed: Oct.24, 1972 21 Appl.No.:29 9,762

[52] US. Cl. 81/5739 [51] Int. Cl B251) 13/46 [58] Field of Search 81/5739, 57.46

[56] References Cited UNITED STATES PATENTS 919,260 4/1909 Smith .1 8l/57.46 3,616,714 11/1971 Gregory.....

3,019,681 2/1962 Gris som 81/5739 X FOREIGN PATENTS OR APPLICATIONS 9/1970 Canada 81/5737 Primary Examiner.lames L. Jones, Jr. Attorney, Agent, or FirmLyon & Lyon 57] ABSTRACT A wrench having a first handle in which a rotatable drive member surrounded by a drive ratchet is journalled, and a second handle is pivotally connected to the first handle. A linkage assembly including a drive pawl connects the second handle to the ratchet so as to cause rotation of the drive member at a faster rate than the rate of pivotal movement of the second handle relative to the first handle. The linkage also connects the second handle to the drive member so as to lock the drive member with respect to the first handle,

. when the second handle is held in fixed relation to the first handle, so that the two handles and drive member may be turned in unison.

7 Claims, 6 Drawing Figures 1 TWO SPEED WRENCH The present invention is directed to a two speed wrench and is summarized in the following objects:

First, to provide a novelly constructed two speed wrench having amain handle and a second handle which, when moved relatively, advances a torquing tool rapidly and which, when moved in unison, turn the torquing tool in unison therewith.

Second, to provide a two speed wrench, as indicated in the preceding object, which incorporates a novel linkage and drive means between the torquing tool and second handle wherein a drive ratio in the order of 9 to 1 may be obtained, so that relatively small movement of the second handle with respect to the main handle, easily obtained by clenching and relaxing ones hand, effects rapid rotation of the torquing tool.

Third, to provide a two speed wrench, as indicated in the other objects which, although comprising inexpensive parts, is particularly sturdy and fully capable of withstanding the forces applied in use.

FIG. 1 is a side view of the twospeed wrench shown in its normal position.

FIG. 2 is an enlarged fragmentary sectional view taken within circle 2 of FIG. 1 showing the parts in their normal position.

FIG. 3 is a similar fragmentary sectional view showing the parts as they appear on completion of a high speed torquing stroke.

FIG 4 is a sectional view taken through 44 of FIG. 2.

FIG. 5 is a sectional view taken through 55 of FIG.

FIG. 6 is a sectional view taken through 66 of FIG.

The two speed torquing wrench includes a main handle 1 formed of heavy gauge sheet metal and including a portion having parallel side walls 2 joined by a connecting web 3 and a handle portion 4 which is essentially tubular. The side walls 2 increase in width as they continue from the handle portion 4 and are, provided with a pair of opposed bearing apertures 5.

A drive member 6 is provided with a central ratchet 7 which fits between the side walls 2 and is borderl 'by journals 8 which are received in the bearing'apertures 5. Drive projections 9 extend from the journals 8. The projections are polygonal in cross section, preferably square, and dimensioned to receive conventional torquing tools such as wrench sockets. While drive projections are preferred, the drive member 6 may be provided with a polygonal bore for connection to wrench sockets by means of torquing bars. In either case, the manner of connection to a wrench socket or similar torquing tool is conventional.

.IDLLM? Speed ch .fllilkiii filfiiifiwnq handle 10 515865556 of heavy gauge sheet metal and including a portion having parallel side walls 11 joined by a web 12. A handle portion 13 of essentially tubular cross section extends from the web and side walls.

The

handles

1 and 10 are joined by a link member 14 pivotally connected by *

pivot pins

15 and 16. The link member 14 is located in the regions of the handles near the junctures between their handle portions and between the

parallel side walls

2 and 11.

A crescent shaped pawl drive lever 17 is pivotally mountedbetween the side walls 2 adjacent the ratchet 7 and joined to the main handle by a pivot pin 18. A

second pivot pin 19 near the pivot pin 18 connects the drive lever 17 to the side walls 11 of the handle 10. The side walls 11 project beyond the web 12 for this purpose.

A spring 20 is connected between the link member 14 and the pawl drive lever 17 to provide a-force tending to move the second handle 10 away from the main handle 1. This movement may be limited by suitable stops, such as a stop 21 engaged by the pawl drive lever 17.

The extended end of the pawl drive lever 17 is provided with a drive pawl 22 which engages the ratchet 7. A spring 23 normally holds the pawl 22 in position for engagement with the ratchet during a drive stroke, wherein the ratchet is turned in a clockwise direction but permits a return stroke without corresponding movement of the ratchet. To prevent such backward movement, a second pawl 24 backed by a spring 25 engages the ratchet.

Operation of the two speed wrench is as follows:

The wrench as viewed in FIGS. 1, 2 and 3 is in position for rotating a nut in a clockwise direction with respect to its bolt. Assuming a right handed thread, this movement screws the nut onto its bolt. By turning the wrench over, the nut may be unscrewed from its bolt.

In either case, while the nut is loose on its bolt, the secondhandle 10 is oscillat ed betweeuhe solid line 2 and respectively; the drive member, including its ratchet 7, is advanced rapidly with respect to the main handle.

Because of the relative proportions of the linkage bev tween the

pivot pins

15 and 16 and between pivot pins 18. and 19, the second handle 10 moves longitudinally with respect to the main handle 1 so as to apply a thrust force on the lever 17 when the handle 10 is oscillated.

Assuming the mechanism between the second handle 10 and the ratchet is proportioned essentially as shown in FIGS. 1, 2 and 3, an 1 1 movement of the handle will cause a movement of the drive member, a ratio of almost 9 to l. A greater ratio may be obtained by reducing the distance between the pivot pins 18 and 19 or increasing the length of the link member 14, or both. It is desirable to maintain the drive ratio so that the amount of movement required of the second handle is well within the' range of movement of ones hand as it is extended and clenched.

When the nut reaches the end of its free travel, and additional force is required to turn the nut, a point is readied...whs iqlatfismqvcment f. t flfles ceases and the handles are turned in unison. When this occurs, further movement of the handles in unison turns the drive member 6 in unison therewith.

Whether the fast movement obtained by oscillation of the second handle 10 occurs or the slower but more powerful movement obtained by the handles moving in unison, the ratchet and pawls operate to turn the nut in a selected direction but permit reverse movement of the handles while the drive member remains fixed; that is, a ratcheting movement may be accomplished.

In the removal of a nut, the slow movement of the handles in unison is first utilized to loosen the nut,

- thereupon the fast movement is used to remove the nut from its bolt.

While a particular embodiment of this invention has been hpwp anqrtes nhe tiSnQLintQQQwlmi the same to the details of the construction set forth, but n ad therinvqnt tt m aces uqhopha s, QQSl fications and equivalents of the various parts and their relationships as come within the purview of the appended claims.

I claim:

1. A two speed wrench, comprising:

a. a main handle;

b. a drive means including a ratchet and a torquing element journalled adjacent one end of the main handle;

c. a drive pawl and a reverse motion preventing pawl engaging the ratchet to limit the drive means to unidirectional rotation with respect to the main handle;

d. a second handle;

e. a first link member and a second link member each pivotally connected to the main handle and second handle and proportioned to cause longitudinal movement of the second handle with respect to the main handle when the second handle is oscillated with respect to the main handle;

. f. one of the link members having an arm continuing therefrom and carrying the drive pawl to effect rotation of the drive means with respect to the main handle when the second handle is oscillated with respect to the first handle.

2. A two speed wrench as defined in claim 1,

wherein:

a. the relative locations of the pivotal axes of the pivotal connections between the link members, and handles and the length of the continuing arm with respect to its link member being such that the extent of rotation of the drive means materially exceeds the extent of the oscillating movement of the second handle with respect to the main handle.

3. A two speed wrench as defined in claim 1,

wherein:

a. the main handle is a single piece member having flat parallel walls in the region receiving the drive means and link members, and having a hand engaging portion of essentially circular cross section.

4. A two speed wrench as defined in claim 2,

wherein:

a. the second handle is a single piece member having flat parallel sides in the region receiving the link members, and having a hand engaging portion of essentially circular cross section.

5. A two speed wrench as defined in claim 1,

wherein:

a. and a spring connects the link members to urge the second handle away from the main handle.

6. A two speed wrench, comprising:

a a main handle including parallel side walls at one end portion having aligned bearing apertures therein;

b. a drive means having journal portions received in the apertures, a ratchet between the walls, and an exposed torquing element;

c. a crescent shaped arm member pivotally mounted between the walls and movable between a retracted position and a partially encircling position with respect to the ratchet;

d. a drive pawl carried by the arm member engageable with the ratchet to effect rotation of the drive means in one direction with respect to the main handle;

e. a pawl carried by the main handle for preventing reverse rotation of the drive means;

f. a second handle oscillatably connected to the arm member in proximity to the pivotal connection between the arm member;

g. a link member extending between and interconnecting the handles arranged to cause the second handle to thrust and retract the arm member and pawl thereby to effect rotation of the drive means when the second handle is oscillated with respect to the main handle.

7. A two speed wrench as defined in claim 6,

wherein:

a. the second handle, when held in fixed relation with respect to the main handle, locks the drive pawl against movement thereby to fix the ratchet against movement in one direction with respect to the main handle, and cause the drive means to turn in unison with the handles upon turning the handles in unison.

Claims

1. A two speed wrench, coMprising: a. a main handle; b. a drive means including a ratchet and a torquing element journalled adjacent one end of the main handle; c. a drive pawl and a reverse motion preventing pawl engaging the ratchet to limit the drive means to unidirectional rotation with respect to the main handle; d. a second handle; e. a first link member and a second link member each pivotally connected to the main handle and second handle and proportioned to cause longitudinal movement of the second handle with respect to the main handle when the second handle is oscillated with respect to the main handle; f. one of the link members having an arm continuing therefrom and carrying the drive pawl to effect rotation of the drive means with respect to the main handle when the second handle is oscillated with respect to the first handle.

2. A two speed wrench as defined in claim 1, wherein: a. the relative locations of the pivotal axes of the pivotal connections between the link members, and handles and the length of the continuing arm with respect to its link member being such that the extent of rotation of the drive means materially exceeds the extent of the oscillating movement of the second handle with respect to the main handle.

3. A two speed wrench as defined in claim 1, wherein: a. the main handle is a single piece member having flat parallel walls in the region receiving the drive means and link members, and having a hand engaging portion of essentially circular cross section.

4. A two speed wrench as defined in claim 2, wherein: a. the second handle is a single piece member having flat parallel sides in the region receiving the link members, and having a hand engaging portion of essentially circular cross section.

5. A two speed wrench as defined in claim 1, wherein: a. and a spring connects the link members to urge the second handle away from the main handle.

6. A two speed wrench, comprising: a . a main handle including parallel side walls at one end portion having aligned bearing apertures therein; b. a drive means having journal portions received in the apertures, a ratchet between the walls, and an exposed torquing element; c. a crescent shaped arm member pivotally mounted between the walls and movable between a retracted position and a partially encircling position with respect to the ratchet; d. a drive pawl carried by the arm member engageable with the ratchet to effect rotation of the drive means in one direction with respect to the main handle; e. a pawl carried by the main handle for preventing reverse rotation of the drive means; f. a second handle oscillatably connected to the arm member in proximity to the pivotal connection between the arm member; g. a link member extending between and interconnecting the handles arranged to cause the second handle to thrust and retract the arm member and pawl thereby to effect rotation of the drive means when the second handle is oscillated with respect to the main handle.

7. A two speed wrench as defined in claim 6, wherein: a. the second handle, when held in fixed relation with respect to the main handle, locks the drive pawl against movement thereby to fix the ratchet against movement in one direction with respect to the main handle, and cause the drive means to turn in unison with the handles upon turning the handles in unison.