US 3279510 A
Description (OCR text may contain errors)
Oct' 18,A 1966 D. 1 DREYER ETAL 3,279,510
SCREW HOLDER AND DRIVER Filed Aug. lO, 1964 57 4235 M f7 g77/.ZH
United States Patent O 3,279,510 SCREW HOLDER AND DRIVER David L. Dreyer, Box 339, R.F.D. 1, Zion, Ill., and Albert H. Allman, 2721 S. 70th, Milwaukee, Wis. Filed Aug. 10, 1964, Ser. No. 388,486 8 Claims. (Cl. 14S-50) This invention relates to screw holders and drivers and, in particular, to a novel screw holder and driver for use with Phillips screws. y
A primary object of the present invention is to provide a screw starter or holder for Phillips screws which is easy to use and reliable in operation.
It is another object of the present invention to provide a Phillips screw holder and driver which is particularly adapted to enable the insertion and withdrawal of Phillips screws to and from congested or otherwise difficult and hard-to-reach locations.
It is a further object of the present invention to provide a screw holder and driver for Phillips screws in which a pair of blades disposed transversely of one another respectively exert a pair of opposite relative force couples to securely grip the screw head. Further, it is a particularly salient characteristic of the present invention that the effective lever arms of the relative force couples are substantially the same in length, thereby enabling the exertion of maximum gripping torques consistent with minimum wear of the blades.
It is a still further object of the present invention to provide a screw holder and driver for Phillips screws having a pair of transversely disposed blades which unlock and apply opposed gripping torques to the screw head Y when suiicient push force is exerted on the screw holder and driver and which lock in a right angle non-gripping relationship when sufhcient resistance to insertion torque is encountered. v
It is an additional object of the present invention to provide a screw holder and driver for Phillips screws having a pair of transversely disposed blades which unlock and apply opposed gripping torques to the screw rhead when a push force is exerted on the screw holder and driver and which continue to apply the opposed gripping torques as withdrawal torque is applied to the screw.
These and other objects and features of the present invention will be apparent from the specification taken together with the accompanying drawings.
In the drawings:
FIGURE 1 is a side view in elevation of a preferred embodiment of the present invention.
FIGURE 2 is an exploded view illustrating the constituent parts of the embodiment of FIGURE l.
FIGURE 2A is a supplementary ligure to FIGURE 2 to aid in the description of the invention.
FIGURE 3 is an enlarged, diametrical view, partially in section, of the forward portion of the FIGURE l ernbodiment in the unlocked, gripping condition.
FIGURE 4 is a View similar to FIGURE 3 with FIG- URE l embodiment in locked set condition.
FIGURE 5 is an end view ofFIGURE 3 with a diagrammatic illustration of the force couples exerted by the blades.
FIGURE 6 is an end view of FIGURE 4.
FIGURE 7 is a cross-section taken at 7-7 of FIG- URE 3.
FIGURE 8 is a side view in elevationof the forward portion of another embodiment in which the locking mechanism is omitted.
FIGURE 9 is a cross-section taken at 9-9 of FIG- URE 8.
Briey, the present invention provides a lholder and driver for a screw of the type having a head provided with a pair of beveled slots intersecting at right angles. The holder and driver comprises rst torque means in- 3,2 79,5 l0y Patented oct. 1s, 1966 ICC cluding a first blade adapted to engage in one of the beveled slots and second torque means including a second blade adapted to engage in the other one of the pair of beveled screw slots. The rst and second torque means are cooperatively adapted to apply a pa-ir of opposing force couples through the first and second blades to the screw head so as to grip the screw. The holder and driver further comprises a drive member on which the rst and second torque means are cooperatively mounted.
Referring now to FIGURES l and 2, there is shown a preferred embodiment of the present invention which includes a drive member 20 which is depicted as a conventional screw driver handle. The handle is not a limitation of the invention since other forms of drive members may be utilized, such as a chuck adapted to be inserted in another tool. In this embodiment, the rst torque means comprises the flat torque member 21 which is fabricated preferably of tool steel or spring steel. The torque member 21 consists of a flat blade 22 and a stem 23 integral with the blade 22. The blade 22 is provided with a pair of beveled side edges 24 which adapt the blade 22 to engage in one of the pair of intersecting beveled slots found in a Phillips screw head. In order that the blade 22 will be compatible with most standard Phillips screw heads, it is preferred that the side edges 24 each be beveled at an angle of approximately 30 and that the beveled edges 24 terminate at a blunted leading edge 2S. It may be found desirable to harden the beveled edges 24 to minimize wear and damage.
The second torque means in this embodiment comprise essentially the torque member 26 together with the spring 27. The torque member 26 is preferably fabricated of-tool steel or punched spring steel and hardened to minimize wear and damage. The torque member 26 consists of a cylindrical casing 28 open at one end and provided at its other end with an inwardly extending annular shoulder 29 on which is carried a flat blade 30 integral with the casing 28. The blade 30 is provided with a central longitudinal :aperture 31 which is co-linear with the axis of the cylindrical casing 28 and which communicates with the interior of the casing 28 through the aperture 32 defined by the annular shoulder 29. The blade 30, like the blade 22, includes a pair of side edges 33 beveled at an angle of approximately 30 and terminating in a blunted leading edge 34. The widths of the respective blades 22 and 30 between their respective pairs of beveled edges 24 and 33 are substantially the same at corresponding points along the lengths of the respective blades 22 and 30. For example, as depicted in FIGURE 2A, the width w at a random point along the length of the blade 30 is substantially the same as the Width w at the corresponding point along the length 0f the blade 22.
The spring 27 is both a compression and torsion spring as will be explained further on. At this point, it suflices to note that the spring 27 includes a projecting end 35 which is adapted to be anchored in the retaining aperture 36 provided in the cylindrical casing 28. The opposite end of the spring 44 is preshaped to lock about the stem 23 of the torque member 21, as depicted in FIGURE 7.
The means for mounting the torque members 21 and 26 on the drive member 20 in this embodiment comprise a plunge-r 36, a locking member 37, and a set screw 45. The plunger 36 is preferably fabricated of tool steel and consists of a shaft 38 provided at one end with a cylindrical head 39. The rearward portion of the head 39 is provided with one or more longitudinal detents or lock notches 40. An axial bore 41 extends through the length of the plunger 36.
The lock member 37 is fabricated, prefer-ably of tool steel, as a cylindrical member provided With one or more locking lugs 42 forwardly extending from its front face. The lock member 40 is further provided with an axial bore 43 extending therethrough.
Referring now particularly to FIGURES 3 and 4,it
is seen that the foregoing constituent parts of this em` 31 is slightly greater than the thickness of the blade 22 so as to permit limited rotation of the torque member 26 relative to the torque member 21. The rearward end of the stem 23` is crimped in the bore 41 of the plunger 36. The shaft 38 of the plunger 36 is, in turn, rigidly atlixed `in the drive member` 20 by the set screw 45. Hence, the torque member 21 is rigidly aiixed to the drive member 20.
The cylindrical casing 28 is rotatably mounted on the cylindrical plunger head 39 with the locking member 37 securely press-lit into the end of the casing 28 and rotatably mounted on the plunger shaft 38. In order to minimize the frictional contact between the plunger head 39 and the cylindrical casing 28, the plunger head 39 is preferably beveled intermediate its ends so as to effectively provide spaced double-ring contact with the cylindrical casing 28. The spring 27 is confined in the cylindrical casing 28 between the forward face. of the plunger head 39 and the annular shoulder 29 in an encircling relationship with the stem 23 of the torque member 21. The projecting end 35 is anchored in the retaining aperture 36 while the opposite end 44 is locked to the stem 23 of the member 21 as shown in FIGURE 7. With this arrangement the spring 27 exerts a torsional force on the torque mem'ber 21 which urges rotation of the torque member 26 with respect to the drive member 20 and torque member 21. In addition, the spring 27 exerts an expansion force which urges the torque member. 26 forwardly with respect to the drive member 20 and torque member 21.
In operation, if the drive is not in the set position shown in FIGURES 4 and 6, the torque member 26 is manually gripped `by its serrated surface 46 and manually rotated against the torsional urge of the spring 27 until it reaches the set position in which the blade 30 isA normal to the blade 22 `as shown in FIGURE 6. At this point, the
`lugs 42 are in alignment with the detents 40'and the expansion urgel of the spring 27 causes the torque member 26 to move forwardly with respect to the drive member 20 and torque member 21, locking the lugs 42 in the detents 40. In this position, the blade 30 is extended a slight distance ahea'd of the blade 22, specifically, a distance equal to the length of protrusion of the lugs 42.
r'The device is now inthe set position shown in FIGURES of the spring 27 causes rotation of the torque member-26 with respect to the drive member 20 and torque member 21 forcing the blades 22 and 30 into the canted relationship depicted in FIGURES 3 and 5 in which the blades bear against respective inner faces of the screw slots. The torsional urge of the spring 27 causes the blades 22 and 30 to respectively apply opposing forcecouples M1 and M2 to the screw head as shown diagrammatically in FIGURE 5, thereby locking the screw to the blades 22 and 30.
It should be noted at this juncture that, with the device in the gripping position of FIGURES 3 and 5, the lead-` ing edges 25 and 34 of the' blades 22 and 30 are substantially coplanar and since the widths of the blades 22 and 30 are the same at corresponding points as previously mentioned and illustrated in FIGURES 2 and 2A, the equal force-vector components F1 of the force couple M1 applied by the blade 22 are exerted with an effective lever arm length D1 which is of substantially the same length as the effective lever arm length D2 of the force couple M2 at which the equal force-vector components F2 are applied by the blade 30. As is well known, the torque M exerted -by any force couple is the product of the magnitude of one of the two equal forces F and the effective lever arm length D. By insuring thatDl. and D2 are substantially the same lin magnitude in thepresent device, the optimum condition of maximum gripping torques consistent with a minimum force-vector magnitude level is achieved, thereby minimizing `wear on the blades 22 and 30 at any given magnitude of gripping torques, a salient feature of this invention.
To this point, it has been assumed `that no driving torque has been applied to the drive member 20. to turn the Phillips screw into its socket. When such insertion torque is initially applied to the screw, it is exerted primarily through the blade 22 since the direction ,of insertion torque exerted on the screw head is opposite` to direction of the gripping torque exerted by the blade 30 on the screw head. However, as resistance to insertion is presented by the screw, the insertion torque overcomes the gripping torque exerted by the blade 30 such that the blade 30 is rotated back toward the set position. When 1 the resistance reaches a suflicient level, the bladeA 30 locks in the set position and the insertion drive torque is equally applied to the screw head by both blades 22 Land 30. This operationalcharacteristic'is advantageousnot only from the .aspect of distributing the insertion torque load to the two blades when the resistance to insertion becomes appreciable, thereby minimizing damage and wear to both the blade` 22 and the screw head, but also because it results in the device beingautomatically returned to set condition when the screw is seated, ready to grip a new screw.
A different operational characteristic occurs whena screw is gripped and withdrawn from a socket. In this circumstance, the direction of withdrawal torque is in the same direction as the gripping torque applied by the blade 30 and there is no tendency to rotate the torque member 26 back into the set position as resistance to withdrawal torque is encountered. Hence, the screw remains locked to the blades 22 and 30 until it is removed by manual rotation of the torque member 26 applied to the serrated surface 46 as previously described. This, of course, is desired in order to withdraw Phillips screws from congested or otherwise dicult locations.
Referring now to FIGURES 8 and 9, there is shown a modified form of the screw holder and driver in which no locking mechanism `is provided. In this modification, the member 50 is identical in structure to the torque member 21 shown in the preceding embodiment withithe limitation that the stem 54 must have sut`n`cient torsional resiliance and, hence, the member-50 is preferably fabrica-ted of spring steel. The torque member y51, in turn, is similar to the torque member 26 inthe preceding embodiment with the blade 52 `being identical to the blade 30 in the preceding embodiment. The torque member 51 is different from the torquemember 26 in the preceding.
embodiment in that it is provided with a longitudinal bore 53 with a diameter only very slightly greater than the width of the stem 54 of the` torque member 50 and includes a threaded radial bore 55 extending through its sidewall to the axial bore 53.l Y
The torque rmember 51 is press-fit into nor otherwisey important to understand that the radial bore 55Nmust be oriented such that when the torque member 50 is mounted in the torque member 51, -the blade 57, when unstressed, is canted with respect to the blade 52. The particular angle of unstressed cant is a matter of design.
In this form of the device, the opposing force couples to grip the Phillips screw head are generated by the torsional resilience of the stem 54 which is caused to twist when blades 52 and 57 are forceably inserted into the respective beveled slots of a Phillips screw head. Hence, in operation the screw must be forced onto and off the blades 52 and 57. This tends to cause wear of the blades 52 and 57, and it is preferably that the beveled edges of these blades be hardened to resist wear. Y
Although certain specific embodiments have been used in illustrating this invention along with specific terminology, it is to be understood that this is merely by way of example and in no manner to be construed as a limitation. It is contemplated that certain modifications may be made within the scope of the claims without departing from the spirit of the invention. For example, it is contemplated that in some instances the blades may be provided with notches or serrations to enhance their gripping capabilities.
What is claimed is:
1. A holder and driver for a screw yof the Phillips type, having a head provided with a pair of beveled slots intersecting at right angles, comprising: a drive member; a first torque member having torisional resilience and provided with an elongate stem integral at one end with a first blade adapted to engage in one of said pair of beveled screw slots; and a second torque member cornprising a cylindrical casing encircling said stem of said first torque member, carrying a second blade at one end, and afiixed to said drive member at its opposite end, said second blade having a longitudinal aperture therein in which said first blade is transversely disposed, said stem of said first torque member being anchored at its other end to said second member in a position such that said first blade is canted with respect to said second blade, whereby when said first and second blades are forceably inserted into said beveled screw slots, opposing relative force couples are exerted upon said screw head by said first and second blades so as to grip said screw head.
2. The holder and driver defined in claim 1 wherein said first and second blades are each provided with beveled side edges and are both substantially the same in width at corresponding points between their respective beveled side edges such Ithat the effective lever arm lengths of said relative opposing force couples are of substantially the same length.
3. A holder and driver for a screw of the type having a head provided with a pair of beveled slots intersecting at right angles, said holder and driver comprising: a drive member; a plunger rigidly affixed in the forward end of said drive member, said plunger comprising a cylindrical shaft provided with an enlarged cylindrical forward head, said cylindrical head being provided with detent means at its rearward end; a first torque member comprising a first blade adapted to engage in one of said pair of beveled screw slots and a stem integral at its forward end with said first blade and rigidly affixed relative to said plunger at its rearward end; a second torque member comprising a second blade adapted to engage in the `other one of said pair of beveled screw slots and provided with a longitudinal aperture therein and a cylindrical casing integral at its forward end with said second blade, mounted for rotation and limited axial movement on said plunger head and encircling said stem of said first torque member with said first blade transversely disposed in said longitudinal aperture; a Ecylindrical lock member mounted for rotation and limited axial movement on said plunger shaft rearwardly of said plunger head and rigidly affixed in the rearward end of said cylindrical casing, said lock member having locking means at the forward end thereof, said locking means being adapted to be aligned and axially engaged with said detent means, said locking means and said detent means being disposed within the interior of said cylindrical casing; a torsion and compression spring interconnecting said first and second torque members and confined within said cylindrical casing between said plunger head and a forward end portion of said cylindrical casing, said spring rotatably biasing said second torque member toward a position wherein said second blade is canted with respect to said first blade and said locking means is not aligned with said detent means, said spring axially biasing said second torque member forwardly with respect to said first torque member, said second torque member being thereby adapted to be forcibly rotated against the force of said spring to a set position wherein said second blade is disposed at right angles to said first blade, 'and lsaid locking means is aligned with said detent means such that spring causes said locking means t-o move forwardly into locking engagement with said detent means and causes said second blade to protrude forwardly of said first blade, said second torque member being further adapted to be unlocked from said set position when said first and second blades are inserted in said beveled screw slots and push force is applied to said drive member moving said locking means rearwardly out of engagement with said detent means such that said spring rotates said second torque member causing vsaid first and second blades to exert relative for-ce couples on said screw head so as to grip said screw head.
4. A holder and driver as defined in claim 3 wherein said detent means comprises a slot disposed axially in the rearward end of said plunger head and said locking means comprises an axially-disposed projection at the forward end of said locking member adapted to be received within said slot.
5. A holder and driver as defined in claim 3 wherein said first and second blades are each provided with beveled side edges and are both substantially the same in Width at ycorresponding points between their respective beveled side edges such that the effective lever arm lengths of said relative yopposing force couples are of substantially the same length.
6. A holder and driver as defined in claim 3 wherein said second torque member rotates into said set position and is locked therein by said xlocking means when substantial resistance to insertion torque is presented by said` References Cited by the Examiner UNITED STATES PATENTS 7/1929 Spofford 145-50 5/ 1962 Ericson l45-50 WILLIAM FELDMAN, Primary Examiner.
R. V. PARKER, I R., Assistant Examiner.