US 3894450 A
A combined screw driving and screw gripping tool with which a screw, being attached to the tool, can be moved towards and away from a screw hole without fear of being accidently dislodged from the tool. The screw driving portion of the tool is provided with at least one resilient tongue like element which extends in the longitudinal direction of the tool and which, when inserted in the tool receiving cavity of a screw or the like, exerts a spring force of such magnitude against its contacting surface of the cavity that the screw is held on the tool against accidental dislodgement therefrom.
Description (OCR text may contain errors)
United States Patent [1 1 Hill et al.
1 COMBINED SCREW DRIVING AND SCREW GRIPPING TOOL  Inventors: Tore L. Hill. Carl Tunbergs vag 9,
Solna; Robert Mankowitsch, Skondalsbrovagen 21, Farstu, both of Sweden  Filed: Apr. 22, 1974  Appl. No.: 462,953
Related U.S. Application Data  Division of Sert No. 236,143. March 1972. Pat.
 Foreign Application Priority Data Mar. 25, 1971 Sweden 1. 3924/71  U.S. Cl 81/72; 145/50 D; 145/50 E;
 Int. Cl... B25b 13/02; B25b 15/02; B2lk 5/16  Field of Search. 145/50 R, A, 50 D. 50 E; 81/72, 76/101 D  References Cited UNITED STATES PATENTS 5l8 472 4/1894 Snyder n /50 E 1 July 15, 1975 2.729998 1/1956 Deliso [45/50 E X 3.286149 1 H1966 Learned 145/50 D FOREIGN PATENTS OR APPLICATIONS 279.711 3/1952 Switzerland 145/50 E Primary Examiner-Donald G. Kelly Assistant Examiner-Marc R. Davidson Attorney, Agent, or Firm-Stevens, Davis, Miller and Mosher  ABSTRACT A combined screw driving and screw gripping tool with which a screw, being attached to the tool, can be moved towards and away from a screw hole without fear of being accidently dislodged from the tool. The screw driving portion of the tool is provided with at least one resilient tongue like element which extends in the longitudinal direction of the tool and which. when inserted in the tool receiving cavity of a screw or the like, exerts a spring force of such magnitude against its contacting surface of the cavity that the screw is held on the tool against accidental dislodgement therefrom.
4 Claims, 15 Drawing Figures ATENTFP .mL I 5 ms SHEET COMBINED SCREW DRIVING AND SCREW GRIPPING TOOL This is a division of application Ser. No. 236,143, filed Mar. 20, 1972, now US. Pat. No. 3,831,648.
The present invention relates to a combined screw driving and screw gripping tool having a tool portion intended to be brought into engagement with a tool receiving recess in the head of the screw for the purpose of turning the screw and gripping the same against accidental displacement.
Screw driving tools of the above type are known which, in addition to a profiled portion intended to fit into the tool receiving recess of the screw are also provided with gripping means, which, when the tool is inserted in the screw, hold the screw firmly in a manner such that the screw can be moved with the tool and inserted in the intended hole without accidental displacement of the screw. The gripping means of the known screw driving tools are active in turning the screw during at least the initial turns and greatly facilitate the task of inserting and removing screws into and out of difficultly reached screw holes, with which the risk of dropping the screw when using a conventional screw driver is ever present.
A screw driver has also been proposed with which there is provided exchangeable screw driving blades which are divided transversely to form two resilient tongues, each of which is offset in a direction opposite to the other. When using screw drivers of this latter type one tongue is placed in the slot of the screw, whereafter, while using the side walls of the slot as a surface of reaction and the resilient properties of the inserted tongue, the other tongue is bent or twisted into the slot, the force exerted by the resilient, oppositely directed tongues against opposing flank surfaces of the slot being sufficient to hold the screw in engagement with the screw driver. In addition to this function, the tongues are also active in turning the screw in the required direction, as with a conventional screw driver.
However, although known tool constructions of the type envisaged are advantageous from the aspect of their gripping function, such tools are often too weak to serve satisfactorily as a screw turning tool, and, moreover, are normally of relatively complicated construction, a fact which is often reflected in the relatively high retail price of such tools. Further, the screw gripping elements, which are secured to the known tool construction as by welding or by other suitable means, are often clumsy and obstruct the view of the person using the tool, which is particularly disadvantageous with respect to small screws.
Further, it is often difficult with such previously known combined screw-driving and screw-gripping tools to insert the blade portion of the tool and its screw-gripping means into the slot of a screw, especially when the screw is located in difficulty reached places, where the view is obstructed or poor.
The object of the present invention is therefore to eliminate the aforementioned disadvantages and to provide combined screw-driving and screw-gripping tools which are relatively easy to manufacture, which are easy to use and reliable, and which are sufficiently strong to fulfil their principle function of tightening and untightening screws.
In accordance herewith the invention is mainly characterized in that there is formed in the profiled portion of the tool as an integral portion therewith at least one resilient tongue which is offset relative to its active position in the receiving cavity of the screw, wherein the profiled portion and the resilient tongue are capable of being simultaneously inserted into the receiving cavity of the screw against the action of the spring force exerted by the tongue, to establish frictional engagement of the tool with the screw.
According to one aspect of the invention, the resilient tongue is connected to the profiled portion of the tool along the whole of its length.
According to another aspect of the invention, the tongue is formed in the profiled portion of the tool so as to be partially separated therefrom.
The invention will now be described in more detail with reference to a number of embodiments thereof diagrammatically illustrated in the accompanying drawing, further features of the invention being disclosed in connection therewith.
In the drawing, FIG. I is a front view of the actual driving portion hereinafter called the blade of a conventional screw driver provided with one embodiment ofa screw-gripping means according to the inven tion and shows the attitude of the gripping means in relation to the remainder of the blade before the blade is inserted in the screw.
FIG. 2 is a side view of the embodiment illustrated in FIG. 1,
FIG. 3 is an end view of the embodiment illustrated in FIG. 1,
FIG. 4 is a front view of a modified form of the embodiment illustrated in FIG. 1 showing the attitude taken by the gripping means before the blade is inserted in the screw,
FIG. 5 is a side view of the embodiment of FIG. 4,
FIG. 6 is an end view of the embodiment of FIG. 4,
FIGS. 7 and 8 illustrate in perspective a Phillips-type screw driver provided with gripping means according to the invention, and showing the tool in different positions of rotation relative to the longitudinal axis of the screw driver,
FIG. 9 is an end view of the embodiment of FIG. 7 and FIG. 8,
FIG. 10 is an end view of a wrench of the Allen key pattern, provided with gripping means according to the invention,
FIG. II is a side view of the embodiment of FIG. 10,
FIG. 12 illustrates a wrench of the Allen key type ac cording to the invention under manufacture, the starting blank of the wrench comprising a stock having, in cross section, the form of an irregular hexagon,
FIG. 13 is a side view of the embodiment of FIG. I2,
FIG. 14 is an end view of the finished Allen key according to the invention, and
FIG. 15 is a side view of the Allen key illustrated in FIG. 14.
In FIGS. 1-3, which illustrate the blade portion of a conventional screw driver provided with screw gripping means according to the invention, there is shown a screw driver blade 10, which is normally made ofa suitable steel or steel alloy material, preferably one possessing relatively good spring qualities. The actual blade 10 may comprise an integral portion of the screw driver shank or may be produced separately and joined to the shank as by swaging for example. The shank of the screw driver normally being made of a material of poorer quality than steel, normally iron.
As will be seen from FIGS. 1-3, the screw driver according to the invention illustrated therein resembles a conventional screw driver and is intended to be used for turning screws of the type having a slot which extends diametrically across the head of the screw.
The illustrated screw driver of the invention comprises a combined screw-driving and screw-gripping tool and, for the purpose of gripping the screws in a manner to prevent them from being accidentally dislodged from the tool, there is provided a special gripping means in the form of one, at least slightly resilient tongue 11 which along the whole of its length is integral with and forms a coherent part of the blade 10. In the illustrated example of FIGS. 1-3, the tongue 11 is thin ner than the remaining portion of the blade 10, and thereby possesses relatively good spring properties. As will best be seen from FIGS. 2 and 3, the tongue is also deformed, as by swaging for example, so that the tongue is offset relative to its active, gripping and driving position in the slot of the screw, namely the position which the blade of the screw driver adopts when inserted and pressed into the slot of the screw. Another important property of the tongue resides in the fact that the outermost end 12 thereof located adjacent the edge of the blade is generally in alignment with the remaining portion of the blade edge 13 while the remainder of the tongue curves away from the end 12, in the illustrated manner. The construction of the screw driver blade is such that together with the resilient tongue 11 it can initially be inserted in the screw slot without the use of force, in the same manner as with a conventional screw driver, whereafter as the blade is pushed deeper into the slot the curved portion of the tongue 11, as a result of its abutment with the coacting sides of the slot, is caused to spring aside, thereby providing such frictional engagement with the sides of the slot that the screw is held firmly on the screw driver blade until such time as the screw driver is intentionally wrenched from the screw. This applies both when putting a screw into its intended hole and when removing a screw from a corresponding hole, and is particularly advantageous in the case of screws located in relatively inaccessable positions. The curve on the tongue 11 can, of course. be arranged in different ways with respect to the profile of the blade and the width or the depth of the slot in the screw.
FIGS 4-6 illustrate a modified embodiment of the combined screw driving and screw gripping tool of the invention, the reference numeral 14 indicating a screw driver blade which generally coincides in shape with the blade of the embodiment shown in FIGS. 1-3, although in the present embodiment the screw driver blade 14 has formed in the longitudinal direction thereof a slot 15 which separates a resilient tongue 16 from the remainder of the blade.
As will best be seen from FIG. 6, the tongue 16 at the actual screw driving end of the tool has an end surface 17 which forms a portion of the original screw driver blade edge 18, that is to say before the slot 15 was made in the blade 14. As will also be evident from FIG. 6, the tongue 16 and the end surface 17 are offset from the remaining portion of the blade edge 18, in accordance with the principle of the invention. It is, however, important that the portion 17 is defined by chamfered portions 19, which are intended to facilitate free insertion of the screw driver into the slot of the screw when seeking the slot with the screw driver blade and tongue. Both when seeking the slot of the screw and when pushing the blade of the screw driver deeper into the slot, in accordance with the invention, the larger charnfered portion 19a of the embodiment illustrated in FIG. 6 ensures that the tongue is suitably located relative the adjacent edge of the slot, whereby the end portion of the tongue is forced into alignment with the blade edge 18 while simultaneously being moved substantially back to its original, uncut position of alignment with the blade edge 18, whereby there is obtained a strong frictional grip between the blade 14 and the screw, sufficient to hold the screw to the blade. The screw can then be carried with the screw driver to the intended hole and inserted and tightened therein without fear of dropping the screw, or conversely the screw can be removed from the hole without fear of it being dislodged from the end of the screw driver.
FIGS. 1-6 illustrate the principle of the invention applied to a conventional screw driver intended for screws having a generally straight slot extending diametrically across the screw head. During recent years, however, screws have been produced which present two slots which intersect each other to form a cross. Concurrently herewith there has also been produced a screw driver provided at the screw driving end thereof with lands and grooves intended for engagement with respective radial portions of the cross-shaped cavity in the screw head. The invention can also be applied with particular advantage to such screw drivers, sometimes generally designated Phillips screw drivers.
FIGS. 7-9 illustrate a Phillips-type screw driver according to the invention in perspective and in end view respectively. FIGS. 7 and 8 illustrate a screw driver in two different positions of rotation around its centre axis. The illustrated screw driver comprises a shank 20 around the end of which grooves 21 have been formed in a conventional manner, the grooves defining lands 22 extending substantially in the longitudinal direction of the shank and converging towards the point of the screw driver; the lands being intended for insertion in corresponding parts of the cross-shaped cavity in corresponding screws.
As will be seen from FIGS. 7-9, and particularly from FIG. 9, one such land 22 is slotted in two radial directions so as to be partially separated from the remaining portion of the screw driver. In the illustrated example, the slot has been produced by milling slots 23 extending in the longitudinal direction of the tool substantially radially to the centre axis thereof, so that the resulting tongue 22 in its longitudinal direction is separated from the tool but retained thereto at the end remote from the screw driver edge. In accordance with the invention, the thus parted land 22 as best seen in FIG. 9 is offset from its active position, i.e., the position it takes in the tool receiving cavity of a screw. The separated land or tongue should have a certain degree of resiliency and should be slightly chamfered on its edge surface to facilitate insertion thereof into the screw slot, whereafter the land is pushed further into the slot. When the screw driver is pushed fully into the screw slot, the land 22 will be forced into alignment with the slot, and in the fully inserted position bears yieldingly against a flanking surface thereof. Depending on the material from which the screw driver is made, the frictional engagement thus obtained may be of such magnitude as to render it necessary to use considerable force when removing a screw from the screw driver.
The principle of the invention can also be applied to screw driving tools of polygonal cross section, such as so-called Allen Keys, i.e., hexagonal bar wrenches used for tightening and untightening fillister head cap screws with a socket head. As mentioned, such tools are made of hexagonal stock and are intended to be inserted in recesses of complementary shape in the heads of bolts, screws etc.
FIGS. and ll illustrate an embodiment of such a wrench constructed in accordance with the present invention, the reference numeral 24 indicating a solid, regular hexagonal profile provided on the actual screw driving end of the tool with chamfered edge surfaces 25, intended to facilitate insertion of the wrench into a corresponding complementary recess in the screw head. By forming a groove or a slot 26 in the wrench from the screw driving end portion thereof, a partially parted resilient tongue 27 is formed, which as shown in FIG. 11 is slightly bent outwardly away from the sectional surface of the tool. When the tool is inserted in the corresponding complementary recess ofa screw, the tongue 27 is guided into the recess by the chamfered surface 28 and is urged into resilient abutment with a flanking surface of the screw recess, to provide strong frictional contact with the flanking surface, with the remaining surfaces of the tool bearing firmly against their respective surfaces of the recess, these surfaces acting as surfaces of reaction. By means of this arrangement, the tool is able to hold the screw, bolt or the like with a relatively large force, and hence it is only necessary to use one hand when inserting the screw into its respective hole or when backing-off the screw and removing it from the hole.
The embodiment of FIG. 10 and 11 presumes that the tool is made of regular hexagonal stock. As will be particularly seen from FIG. 11, the tongue 27 of the tool illustrated therein when inserted in the screw, i.e., when taking its screw driving position, is located at the original slot distance from the remaining portion of the tool, which normally means that the tongue is unable to transmit the same torsional force as the remaining, coherent surfaces located around the centre of the tool.
It is, however, desirable in certain cases to improve the turning effect afforded by the tongue, and with this purpose in mind the tool as illustrated in FIG. 12 I5, can be made from a stock having a slightly modified, somewhat irregular hexagonal cross section. As will be seen from FIGS. 12 and 13, a hexagonal stock can be produced, e.g. by drawing, whose one flat 29 is located further away from the centre of the stock than the remaining flats, whereby the tongue 30, produced by making a slot substantially parallel to one flat, is unable to pass directly into the recess of a corresponding screw.
By deforming the tongue at the root end thereof, as by swaging for example, the tongue 30 is brought into closer alignment with the recess in the screw and when pressed into the recess affords the same efficient gripping effect as the tongue of the embodiment illustrated in FIGS. 10 and 11. Further, the tongue 30 when inserted fully in the slot bears directly against the surface of the tool 32, whereby the tool as a whole, including the tongue, acts as a complete wrench for turning the screw.
Although the embodiment of FIGS. 10 15 has been illustrated with reference to a hexagonal wrench, it will be readily understood that the principle of the invention can also be used with other tools of varying cross section intended for turning screws etc. Further, more than one resilient tongue can be formed.
The resilient tongue may be given any suitable cross section with all the described and illustrated embodiments.
The invention is not restricted to the described and illustrated embodiments thereof, but can be modified within the scope of the following claims.
1. An elongated tool for turning a screw having a recessed head with a plurality of engaging surfaces in said recess, said tool comprising a hexagonal wrench having six lands intended to fit into the complementary recesses in a corresponding screw, all of said lands except one being positioned so that the longitudinal plane of the land is parallel with the longitudinal axis of the too], said one land being sprung away from parallel relationship with its longitudinal plane at an angle to said longitudinal axis thus forming a resilient tongue which will internally grip the screw head recess in a snugly fitting manner, said one land being defined by a groove cut into the solid portion of the tool from one end thereof, said groove being in the longitudinal direction of the tool and separating the resilient tongue from the remaining portion of the tool, said tongue being bent outwardly from the center of the tool with the end surfaces of the tool including the end surface of the resilient tongue being chamfered to facilitate insertion of the tool into the complementary recess in the screw.
2. A method for producing a hexagonal wrench intended to fit into the complementary recesses in a corresponding screw, from a stock having a somewhat irregular hexagonal cross section in which one flat is located further away from the center of the stock than the remaining flats comprising making a slot substantially parallel to said one flat whereby a tongue is produced and deforming said tongue at the root end thereof whereby the tongue is brought into closer alignment with the reinforcing portion of the stock and is adapted to be pressed into the recess of the screw.
3. A method according to claim 2 wherein said stock having the somewhat irregular hexagonal cross section is obtained by drawing.
4. A method according to claim 2 wherein said deforming step is preformed by swaging.