US 3577816 A
Description (OCR text may contain errors)
United States Patent 1 3,577,816
 Inventors Jerry Alexander ABSTRACT: A ratchet type wrench wherein a pair of swinga- 64 Hedgerow Lane, Jericho, N.Y. 11753; ble handles swing around a ratchet and have a pair of pawls IrvingJ. Stevens, 130 Margaret Blvd., which respectively coact with the ratchet to turn the latter in Merrick, N.Y. 11566 one direction with respect to one handle when the other han-  Appl. No. 815,074 dle is turned in a given direction and prevents backlash while  Filed Apr. 10, 1969 providing positive ratcheting both forward and reverse  Patented May 4, 1971 without friction applied to the wrench. The wrench is of a relatively small size and is extremely thin so that it is capable of being used where only a small operating space is afforded. A
 RATCHET WRENCH very small radius of arc is required to effect a ratchet move- 10 Claims, 5 Drawing Figs. ment. The pair of handles are relatively thin and are main-  Us fl 81/63 1 tained close to each other with these handles respectively hav-  Int Bzsb ing outer exterior side surfaces directed away from each other [501 aidorsea3333;313:1133:11113111333333?"1133313331: 81/60 61 andrespectivelwmdSubstantiallyplanesnmlwthe axis of the rotary ratchet. The distance between these planes is l 5739 actually the maximum thickness of the entire wrench. One
56] R f n e Ci d handle is used for stabilizing the wrench, and the other is used UNITED STATES PATENTS for driving the ratchet. In addition, the entire wrench is composed of components which require no lubrication for effec- 871,690 11/1907 Gehner 81/63.1 five o peration and which can be sterilized without suffering 3,0 Gl'lSSOm 8 y deleterious r so h the wrench lends to medi Primary Examiner-Travis S. McGehee cal uses such as, for example, in connection with dental opera- AttameySteinberg and Blake tions.
Patented May 4, 1971 3,577,816
' nvvmv'rons JERRY ALEXANDER IRVING J.STEVENS BACKGROUND OF THE INVENTION The present invention relates to wrenches.
In particular, the present invention relates to ratchet wrenches of the type where a pair of swingable handles coact through a pair of pawls with a rotary ratchet for turning the latter in one direction with respect to one handle when the other handle is turned in a given direction.
Conventional wrenches of this general type have only one handle and therefore ratchetting occurs only when friction is encountered. In addition, they are large and bulky since they are required to exert a considerable torque. The moving components of such wrenches require a large radius of arc for ratchet movement, require lubrication for their best operation, and the conventional wrenches are heavy and incapable of being used at locations where only a small operating space is available. Moreover, the components of conventional wrenches are such that they will corrode, particularly if proper lubrication is lacking.
SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a wrench of the above general type which will avoid the drawbacks encountered in conventional wrenches, as set forth above.
Thus, it is an object of the present invention to provide a ratchet type of wrench which while. having a pair of handles which can be turned one relative to the other to operate the wrench, nevertheless is exceedingly small and compact so as to make it possible to carry out operations in confined locations where little operating space is available, and perform positive ratchetting in either direction without backlash.
In particular, it is an object of the invention to provide a wrench of this type which can be operated within the mouth of a dental patient.
It is also an object of the present invention to provide a wrench of this general type which requires no lubrication for proper operation and which can be subjected to sterilization procedures without suffering any deleterious effects.
Furthem'lore it is an object of the invention to provide a wrench of this general type which can be operated without the possibility of injuring or marring surfaces in the region of the wrench during the operation thereof.
Thus, it is an object of the invention to provide a wrench of this general type which is composed of a small number of rugged reliably operating elements easy to assemble and disassemble so that the wrench can be manufactured and sold at a relatively low cost.
The wrench of the invention includes a rotary ratchet means and a pair of handle means extending around the rotary ratchet means for swinging movement with respect thereto. The pair of handle means are located beside each other along the axis of the rotary ratchet means and respectively carry a pair of pawl means which respectively coact with the rotary ratchet means for turning the latter with respect to one of the handle means when the other of the handle means is turned in a given direction. The pair of handle means respectively have exterior side surfaces which are directed away from each other and which are located substantially in planes normal to the axis of the rotary ratchet means, and the distance between these planes determines the maximum thickness of the entire wrench.
BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:
FIG. 1 is a top plan view of a wrench of the invention showing the pair of handle means angularly displaced one with respect to the other;
FIG. 2 is a side elevation of the wrench of FIG. I where the pair of handle means are shown, however, in angular alignment one above the other;
FIG. 3 is a transverse sectional elevation taken along line 3-3 of FIG. I in the direction of the arrows;
FIG. 4 is a sectional plan view taken along line 44 of FIG. 3 in the direction of the arrows; and
FIG. 5 is a sectional plan view taken along line 5-5 of FIG. 3 in the direction of the arrows.
DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, the ratchet wrench 10 of the invention illustrated therein includes a rotary ratchet means 12. This rotary ratchet means 12 is in the form of a cylindrical body made, for example, of stainless steel, and being formed with an axial bore extending completely therethrough. The rotary ratchet means 12 has the configuration of a simple right cylinder which is formed with an axial cylindrical bore passing therethrough, except for the exterior surface of the rotary ratchet means 12. Thus, as is shown in FIG. 3, the rotary ratchet means 12 is formed at its exterior surface with a pair of annular grooves 14 coaxially surrounding the axis of the ratchet 12. In addition the teeth of the ratchet 12 are in the form of a pair of circumferential rows of indentations 16. As is apparent from FIG. 4 as well as FIG. 3 these indentations 16 each have the configuration of part of a simple right cylinder at an end of the latter. Finally, the rotary ratchet means 12 is fonned, as indicated most clearly in FIG. 5, with a pair of coaxial opposed interiorly threaded radial bores 18 for a purpose referred to below.
A pair of handle means 20 and 22 respectively surround and are swingable with respect to the rotary ratchet means 12. The pair of handle means 20 and 22 respectively have head members 24 and 26 which aresituated next and coact directly with the rotary ratchet means, while the pair of handle means respectively include elongated rods 28 and 30 which can conveniently be manipulate to operate the wrench 10. Thus, at their outer ends which are distant from the rotary ratchet means 12 the pair of heads 24 and 26 may respectively be formed with bores which have inner closed ends and which receive elongated end portions of the rods 28 and 30. Cross pins 32 and 34 (FIG. 1) respectively extend into aligned bores of the heads 24 and 26 and transversely through and beyond transverse bores respectively formed in the rods 28 and 30 at their inner end regions which are received in the bores of the heads, so that in this way the rods 28 and 30 are fixed with the heads 24 and 26, respectively. These head members 24 and 26 may be made of a lighter metal which will not corrode, such as aluminum, for example, although if desired the head members 24 and 26 also may be made of stainless steel. They are fonned with coaxial bores in which the ratchet 12 is received with a snug fit providing for direct sliding engagement of the handles with the exterior side surface of the ratchet 12, but requiring no lubrication. The rods 28 and 30 may be made of stainless steel, for example. i
As is apparent particularly from FIG. 3, a washer 36 surrounds the ratchet 12 and is situated between and engages the pair of head members 24 and 26 so that the thickness of this relatively thin washer 36 provides the slight clearance between the pair of head members 24 and 26 of the pair of handle means 20 and 22, respectively.
A retaining means is provided for retaining the ratchet means 12 against axial movement with respect to the pair of swingable handle means. This retaining means in the illustrated example includes a pair of springy flat snap rings 38 and 40 respectively received within the grooves 14 and respectively engaging exterior side surfaces of the head member 24 and 26 which are directed away from each other. As is apparent from FIG. I, the snap rings have spaced elongated endportions 42 formed with openings for respectively receiving the tips of a spreader tool which spreads each snap ring in connection with assembly and disassembly of the components, in a well-known manner.
As is apparent from FIG. I, the exterior surface 44 of the head member 24, where the snap ring 38 is located, is provided with an inscribed radial line 46 while the exposed end face of the ratchet 12 is provided with a radial line 48. Therefore, assuming that the wrench is arranged as shown in FIGS. 1 and 2 with the lower handle 22 maintained stationary, the angular displacement of the lines 46 and 48 one with respect to the other during operation of the wrench will give an indication of the extent to which the ratchet 12 has been turned.
The pair of head members 24 and 26 are respectively formed with bores 50 and 52 extending from the surfaces of the head members 24 and 26 visible in FIG. 2 all the way up to the bores of the head members which receive the ratchet 12 with the rightmost parts of the bores 50 and 52, as viewed in FIG. 1, extending tangentially with respect to the exterior surface of the ratchet 12. These bores 50 and 52 are respectively threaded in the'region of their outer ends and respectively slidably carry pawl members 54 and 56 in the region of their inner ends to extend through and beyond these inner bore ends into engagement with the ratchet 12. The outer interiorly threaded portions of the bores 50 and 52 receive the set screws 58 and 60, respectively. The pair of pawl means include not only the pawls 54 and 56 as well as the set screws 58 and 60 but also springs 62 and 64 which are respectively accommodated together with the pawls and set screws in the bores 50 and 52 in the manner shown in FIGS. 3 and 4. Thus it is possible to turn the set screws 58 and 60 so as to adjust, respectively, the compression of the springs 62 and 64 and thus adjust the pressure with which the pawls 54 and 56 are respectively urged toward the ratchet 12. The indentations l6 each form part of a right cylinder which has with respect to the axis of the ratchet an inclination matching that of the bore 50 or the bore 52 when the pawl 54 or 56 is received in an indentation 16. The surface of each pawl indentation 16 which engages the end of the pawl member 54 or 56 is at the time of engagement normal to the axis of the pawl while the concave side surface of each indentation 16 extends along a cylinder matching the cylindrical side surface of the pawl 54 or 56, so that in this way an exceedingly efficient coaction is provided between the ratchet and pawl members while the latter can be very inexpensively manufactured of elements in the configuration of simple right cylinders.
In the illustrated example the hollow interior bore of the ratchet means 12 receives a socket means 66 made up of a pair of components 68 which coact to form a split socket member having an axial bore of square cross section in the illustrated example. The pair of components 68 are respectively formed with indentations which receive the inner ends of a pair of set screws 70 respectively threaded completely into the opposed threaded radial bores 18 of the ratchet 12, so that in this way the coacting pair of components 68 of the split socket member are releasably fixed in the ratchet against axial or angular movement with respect thereto.
As is apparent particularly from FIGS. 2 and 3, the pair of handle means 20 and 22 respectively have exterior side surfaces 72 and 74 which are directed away from each other and which are located substantially in a pair of parallel planes 76 and 78, respectively, which are normal to the axis of the rotary ratchet means 12. These parallel planes 76 and 78 are spaced from each other by a distance a which determines the maximum thickness of the entire wrench 10. Thus, although the free ends of the rotary ratchet 12 extend beyond the undercut surfaces of the heads 24 and 26, they terminate substantially at the planes 76 and 78. Moreover, all of the remaining components of the entire wrench are situated between these planes 76 and 78. Because it is possible with the structure of the invention to make the head members 24 and 26 relatively thin as well as to situate them relatively close to each other as determined by the thickness of the washer 36, the maximum thickness a of the wrench can be maintained at an extreme ly small value enabling the entire wrench to be situated within an extremely confined space such as within the mouth of a dental patient. Thus, the wrench of the invention can be used, for example, to turn the square shank of a dental implant with this square shank extending into the bore of the socket means 66. Moreover, because all of the components are made of materials which will not corrode and which do not require any lubrication, it is possible to subject the entire wrench to sterilizing operations without any deleterious effects.
As is apparent from the drawings, the wrench 10 can be situated in its position of use with the rod 30 of the lower handle 22 held by the fingers of one hand while the rod 28 is swung back and forth with the remainder of the handle 20 about the axis of the ratchet. With such an arrangement when the upper handle 20 is swung in a clockwise direction, as viewed in FIGS. 1 and 2, the ratchet will be turned with respect to the lower handle 22, while when the upper handle 20 is swung back to the region of its initial position the upper pawl 54 will simply ride along the exterior of the ratchet 12 which is maintained against turning by the lower pawl 56. in this way the upper handle 20 can be conveniently swung back and forth the number of times required to achieve the desired extent of turning of an element received in the socket 66. Moreover, the extent of turning will be indicated by the inscribed lines 46 and 48.
To obtain rotary movement of an element in the reverse direction the wrench need only be turned over so that the handle 20 is maintained stationary while the handle 22 is swung back and forth in the same way. The lower end face of the ratchet 12, as viewed in F 16$. 2 and 3, and the lower undercut surface of the lower handle 22 of FIGS. 2 and 3 are respectively provided with inscribed lines corresponding to the lines 46 and 48 so that when the wrench is reversed there will also be an indication of the extent of angular turning of the socket.
1. A wrench comprising rotary ratchet means, a pair of elongated handle means extending around and being swingably connected with said rotary ratchet means, said pair of handle means being located beside each other along the axis of said rotary ratchet means, retaining means coacting with said pair of handle means and said rotary ratchet means for retaining the latter against axial movement with respect to said pair of handle means, and a pair of spring-pressed pawl means, respectively carried by said pair of handle means and respectively coacting with said rotary ratchet means for turning the latter about its axis with respect to one of said handle means when the other of said handle means is turned in a given direction, said pair of handle means respectively having in the region of said ratchet means a pair of exterior side surfaces located substantially in planes, respectively, normal to the axis of said rotary ratchet means and situated from each other by a distance which determines substantially the maximum thickness of the entire wrench.
2. The combination of claim 1 and wherein a socket means is removably carried by said rotary ratchet means in the interior thereof.
3. The combination of claim 1 and wherein said pair of handle means are respectively formed in the region of said exterior side surfaces thereof with undercut portions beyond which opposed end portions of said rotary ratchet means extend while remaining substantially within the space between said planes.
4. The combination of claim 1 and wherein a washer surrounds said rotary ratchet means and is situated between said pair of handle means for maintaining them at a distance from each other determined by the thickness of said washer, said retaining means including a pair of snap rings situated at exterior surfaces of said pair of handle means which are respectively directed away from said washer and surrounding and engaging said rotary ratchet means to maintain the later against axial movement with respect to said pair of handle means.
5. The combination of claim 1 and wherein said pair of pawl means are respectively situated entirely within said pair of handle means except for active end portions of said pair of pawl means which respectively coact with and engage said rotary ratchet means.
6. The combination of claim 5 and wherein said rotary ratchet means is formed with two circumferential rows of indentations respectively situated at the elevation of said pair of an end region thereof for receiving a substantially matching end region of a pawl member.
9. The combination of claim 1 and wherein a socket means is removably carried by said ratchet means in the interior thereof, said socket means including a pair of components forming a split socket member and capable of being individually introduced into said ratchet means when displaced axially therealong, and a pair of set screws carried by said ratchet means and coacting with said components to releasably maintain the latter within said ratchet means while preventing axial or rotary movement of said socket means with respect to said ratchet means.
10. The combination of claim 1 and wherein all of the components which make up the entire wrench are made of materials which are capable of operating effectively without lubrication and which are capable of being sterilized without any deleterious effects.