US2708856A - Slidable side jaw wrench - Google Patents

Description

y 1955 P. s. BRYNGE SLIDABLE SIDE JAW WRENCH Filed July 1. 1953 FIG.

INVENTOR.

GUNNAR BRYNGE PER ATTORNEY United States atent SLIDABLE SIDE JA'W WRENCH Per Gunnar Brynge, Fannalund, Enkoping, Sweden Application July 1, 1953, Serial No. 365,451

Claims priority, application Sweden May 7, 1953 1 Claim. (Cl. 81-165) The present invention relates to an improvement in such wrenches in which a movable jaw is guided in the head of the wrench, partly by means of a rod-shaped cam provided with teeth at its enlarged outer edge, said guide cam running in a longitudinal guide groove in the head of the wrench, which guide groove widens towards its bottom, and partly by flat sliding planes formed on the movable jaw, said planes being displaceable along fiat guide planes provided on both sides of the opening of the guide groove.

In the manufacture of such wrenches it is important that the movable jaw is guided with as little play as possible in the head of the wrench. Such a guiding can be eifected in several ways. Hitherto the enlarged portion of the guide cam has usually been formed so as to fit as exactly as possible in a cylindrical groove portion at the bottom of the guide groove. T o fit the guide cam in such a manner requires a highly developed work of precision, as a comprehensive grinding must be carried out'after the head of the wrench and the movable jaw have been hardened. However, in the mass-production which is concerned in this case such a work of precision is not well adapted, and for a long time it has been tried to mount the guide cam in such a manner, that such an accurate and comprehensive work will not be necessary.

According to the present invention this is made pos- 1 sible by abandoning a comprehensive mounting of the enlarged portion of the guide cam, said guide cam being at the sides facing the opening of the guide groove formed with flat, inclined sliding planes, which form an obtuse angle with the side walls of the guide groove and rest against correspondingly inclined guide planes in the wall of the widened guide groove portion, so that the movable jaw is guided completely in the horizontal as well as in the vertical direction by the said sliding planes and guide planes, only in connection with the sliding planes and guide planes cooperating with each other at the opening of the groove. Thus, according to the invention the enlarged portion of the guide cam is not mounted against cylindrical guide surfaces, which provides a satisfactory guiding only if there is no play between the guide cam and the cylindrical guide surfaces. Otherwise the mounting will not be satisfactory and will only cause linear contact. Due to the fact that the movable jaw is mounted in accordance with the present invention the position of the jaw, horizontally as well as vertically, will be entirely determined by the sliding planes and the guide planes alone, and the tolerances of these planes, both with regard to the mutual distance and to the angular position and the plane parallelism, can easily be obtained by grinding after the hardening, which grinding is necessary on account of the deformation by hardening. Thus, the demands for accuracy are limited to the sliding planes, and the guide planes, whereas the shape of the guide groove does not influence the adequate mounting of the movable jaw. Guided by the guide planes formed in the widened portion of the guide groove an adjustment grinding of the two guide planes provided at the opening of the guide groove can easily be carried out after the hardening.

According to one embodiment of the invention the latter guide planes may either be located in the same plane or inclined in relation to each other. If the guide planes are inclined so much that they form an acute angle with the side walls of the guide groove, the movable jaw will at the same time serve as a bridge portion uniting the walls of the guide groove, said bridge portion preventing the walls of the guide groove from moving away from each other, if the wrench is subjected to too great strain. An embodiment of the invention is illustrated in the accompanying drawing in which Fig. 1 shows a perspective view of the wrench and Fig. 2 a wrench taken apart, also in perspective view. Fig. 3 shows a cross section of the wrench according to Figs. 1 and 2. Figs. 4 and 5 show other embodiments in similar cross sections. The reference numeral 1 designates the head of the wrench with a stationary jaw 2 and a handle 3, and 4 designates the movable jaw. In the head 1 of the wrench a guide groove is provided in the form of a narrow groove 5 and a groove 6 widened towards the bottom. On both sides of the opening of the guide groove 5 a pair of guide planes 7 are provided, which planes in the embodiment according to Figs. 1 3 are located at right angles to the side walls 8 of the guide groove 5. On both sides of the groove 5 the walls of the groove 6 are made in the form of plain guide planes 9 which are inclined in relation to each other and form an obtuse angle with the side walls of the groove 5. The guide cam of the movable jaw 4 consists partly of a web portion 10 corresponding substantially to the guide groove 5, and a rod-shaped portion 11. At the union between the web portion 10 and the jaw proper 4 this is formed with a pair of sliding planes 12 corresponding to the guide planes 7, while a pair of inclined sliding planes 13 are formed at the union between the web portion 10 and the rod-shaped portion 11. These sliding planes are intended to engage the guide planes 9, and the distance between the guide planes 7 and 9 is so measured in relation to the distance between the sliding planes 12 and 13 of the movable jaw 4, that there will be as little play as possible between the head 1 of the wrench and the movable jaw 4, when said jaw is displaced in the head. The rod-shaped portion 11 of the guide cam is in the usual manner provided with teeth 14 intended to cooperate with an adjustment screw 17 turnable on a pivot 16 and inserted in an opening 15 in the head 1 of the wrench, said screw 17 being given a certain resilient self-adjustment on the pivot by means of a screw spring 18 threaded on said pivot and acting against the adjustment screw.

As can be seen, particularly from Fig. 3, the movable jaw is very well fitted in the head 1 of the wrench according to the present invention, solely by the cooperation of the sliding planes 12, 13 with the guide planes 7 and 9 respectively because a guidance vertically as Well as a guidance horizontally are obtained, due to the inclined guide planes and sliding planes 9 and 13. Due to the fact that these guide planes and sliding planes 9 and 13 are inclined, as stated above, so that obtuse angles are formed between the transition of the planes into the adjacent parts of the guide groove walls 8 of the stationary wrench head respectively into the web portion 10 of the guide cam, the grinding of the guide planes and the sliding planes is greatly facilitated, and sharp edges, which are easily damaged, are avoided.

In the embodiments according to Figs. 4 and 5 the guide planes 7 and the sliding planes 12 corresponding to said guide planes are placed angularly in relation to each other, whereby an additional horizontal guiding of the movable jaw is obtained. By choosing the inclination of the guide planes 7, as shown in Fig. 4, so that they form an acute angle with the side walls 8 of the guide groove 5, the

movable jaw will as stated above, simultaneously serve as a bridge portion uniting the wall portions of the guide groove 5.

Having now particularly described the nature of my invention and the manner of its operation what I claim is:

In a slidable side jaw wrench, a stationary head formed with one jaw of the wrench and having an elongated slot, a movable member formed with the second jaw of the wrench and having an elongated key portion slidably fitted in said slot and formed with rack teeth, an adjusting Worm rotatably mounted in said head in mesh with said rack teeth for side way adjustment of the second jaw, said key having an upper portion with parallel side walls joined to the second jaw by plane guide surfaces forming an angle with said parallel side walls and an enlarged bottom portion joined to said upper portion by plane wall members forming an obtuse angle with said parallel side walls, and said key slot having an upper portion and an enlarged bottom portion fitting the respective portions of the key with a loose fit, said upper porportion by plane slanted wall members, the said guide surfaces and the said wall members of the key and the slot respectively being correlated as to slant and spacing in the direction of the depth of the slot so that the respective guide surfaces and wall members of the key and the slot engage each other with a close fit whereby the key is closely guided in longitudinal direction and perpendicularly thereto.

References Cited in the file of this patent UNITED STATES PATENTS 953,346 Newbauer Mar. 29, 1910 1,617,488 Johnson Feb. 15, 1927 1,805,298 Schweigert May 12, 1931 1,975,908 Swanson Oct, 9, 1934 2,596,266 McEnroe May 13, 1952 FOREIGN PATENTS 19,623 Great Britain 1894 409,652 France Apr. 28, 1910 102,430 Sweden Dec. 23, 1939

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