|Publication number||US3645161 A|
|Publication date||Feb 29, 1972|
|Filing date||Nov 18, 1969|
|Priority date||Nov 18, 1969|
|Also published as||CA927634A, CA927634A1|
|Publication number||US 3645161 A, US 3645161A, US-A-3645161, US3645161 A, US3645161A|
|Original Assignee||Pic Design Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Referenced by (51), Classifications (4), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Waited @tates Patent Weaker 5] Feb. 29, 1972  SULDER TIP SETSCREW 2,086,221 7/1937 Gwyn ..85/l SS 2,747,058 5/1956 Ulanet ...85/1 SS  went weske" East Rmkaway 3,501,993 3/1970 Swenson ..s5/1 ss P1 E  Asslgnee C Design Corp ast Rockaway N Y FOREGN PATENTS OR APPLICATIONS  Had: 1969 466,211 5/1937 Great Britain ..151/24  Appl. N0.: 877,695
Primary ExaminerEdward C. Allen 52 11.5.01. ..ss/1 ss Ammeyqames and Franklin  111}!- CI I ..Fl6|l) 35/00 57 ABSTRACT  Field of Search ..85/l SS; 269/249, 274;
2 7/529 51 24 A setscrew comprising a rounded soft metal tip extending from a threaded shaft. The soft metal tip is adapted to contact  References Cited a member against which it is forced without damaging deformation to the member or the tip. The setscrew is constructed UNITED STATES PATENTS by melting a piece of soft metal on to a recessed portion in the end of the threaded shaft. 1,046,823 12/1916 McBerty ..85/l SS 1,581,096 4/ 1926 Barnes 5 Claims, 6 Drawing Figures SOLDER TIP SETSCREW The present invention relates to a setscrew adapted to hold two members in substantially stationary relationship. The setscrew of the present invention is described in connection with preventing rotational movement of two concentric members but may be used with members of various shapes and designs.
Setscrews of the type here described generally consist of a threaded shaft adapted to be screwed into one member and to contact a second member and hold it in relative stationary relationship. In designing setscrews of this type a balance must be struck between three important considerations. First, the material at the end of the threaded shaft adapted to contact the second member must be of a type such as to cause a minimum of damage to the second member upon contact therewith and the application of compressive force. Second, the material must be of a type such as to withstand the compressive force applied upon contact with the second member without deforming to a shape in which it is-no longer useful for its intended purpose. Third, the engagement between the material and the second member must be effective to hold the second member stationary.
It is a primary object of the present invention to devise a setscrew with a tip portion of a material and shape particularly suitable for continued and repeated contacts in holding relationship with a member.
It is a further object of the present invention to devise a setscrew which is easily manufactured and in which a contacting tip is automatically formed in a desired shape without the necessity of machining.
It is still a further object of the present invention to devise a setscrew with a contacting tip of a soft metallic material in which a minimum of such material is wasted during manufacture.
It is another object of the present invention to devise a setscrew utilizing a contacting tip of a material and shape such that a minimum of tip material will sustain a maximum useful life.
The setscrew of the present invention comprises a threaded shaft with a recessed portion at one end. A soft metal insert is positioned in said recess and extends beyond the end of said shaft in a rounded or convex configuration.
It has been found that conventional setscrews of the type here described which utilize nonmetallic tip inserts, such as nylon, become inoperative after they have been used only a few times to lock two members in stationary relationship. The tip in such devices tends to deform and sometimes crack in outward radial direction upon the application of the compressive force necessary to hold the two members in stationary relationship. This spreading in an outward direction tends to interfere with the insertion of the threaded shaft into the first member. Moreover, continual use. of a setscrew with a tip which has been so deformed may result in a complete severance of the tip portion from the threaded shaft, the tip portion thereafter remaining jammed in its holding position. The difficulty is partially due to the conventional cylindrical shape of such tips. As is well known, a member of such shape will tend to deform radially outwardly upon the application of compressive forces at its ends. This type of deformation is aggravated if the surface of the member which contacts the cylindrical tip is rounded because in such a case the compressive force is exerted unevenly on the end surface of the cylindrical tip.
I have found that a setscrew comprising a tip of soft metal is particularly well suited for repeated compressive contact with a member adapted to be held. Moreover, I have found that such a soft metal tip when formed in a rounded or convex configuration displays a pattern of deformation, after repeated contact with the member to be held, which does not interfere with the insertion of the threaded shaft into the first member and does not weaken the tip, as by cracking.
Moreover, a soft metal tip of the type used in the present invention is more readily adapted to conform to the shape of the member it holds after repeated contact with such member. As
a consequence, the tip becomes more, rather than less, effective in preventing unwanted relative movement after repeated use.
To the accomplishment of the above, and to such other objects as may hereinafter appear, the present invention relates to a setscrew as defined in the accompanying claims and as described in this specification, taken together with the accompanying drawings in which:
FIG. 1 is a cutaway side elevation of the setscrew of the present invention, the cutaway portion showing the tip material inserted in a conical recess of the screw shaft;
FIG. 2 is a front view of the setscrew of FIG. 1;
FIG. 3 is a cutaway side elevation of the setscrew in its operative environment;
FIG. 4A is a side elevation of a prior art setscrew with a Cylindrical tip portion of a material such as nylon;
FIG. 4B is a side elevation of the setscrew of FIG. 4A showing the deformation of the tip material after repeated use; and
FIG. 5 is a side elevation of the setscrew of the present invention showing the deformation of the tip material after repeated use in the environment of FIG. 3.
As best shown in FIG. 1, the setscrew of the present invention comprises an externally threaded screw body generally designated 10 with a driving recess 12 at one end, as is conventional. In the form here shown the driving recess 12 is designed to accommodate an Allen-head wrench, but this is of course merely a matter of choice. The tip of the screw body 10 is provided with a tapered or bevelled portion 18 terminating in a flat circular end 19. A recess 14 extends axially into the screw body 10 from the tip end 19, and is provided with inwardly tapering walls, the preferred form here disclosed being substantially conical in shape. A slug 16 of soft metallic material is received within the recess 14 and extends axially out therefrom, the outwardly extending part terminating in a rounded configuration. It is preferred that the tapered scrcw surface 18 extend all the way to the recess 14 and that the rounded outer surface of the slug 16 extend all the way to the screw surface 18, preferably merging with the surface 18 with little or no discontinuity as illustrated in FIG. I.
The device may advantageously be manufactured by placing a mass of appropriate soft metal in or on the recess 14 and then melting the mass so that it flows into and conforms to the shape of the recess 14. The mass of soft metallic material in its original form may take any suitable shape, as determined by the availability of the material in question. Thus, it may be in the form of individually produced spherical globules, or in the form of small cylinders cut from a rod of the material in question, or even in the form ofa collection of small particles. The initial shape of the mass of soft metallic material is of little significance, since when it melts it will change its shape to conform to the particular configuration of the recess 14. The significant feature is that the amount of soft metallic material provided is appropriate to the volume of the recess 14 in order to substantially fill that recess and to project out therefrom. The mass of molten soft metal, when it cools and hardens, will inherently, by virtue of surface tension, solidify with a rounded exposed surface, the radius of curvature of which will depend upon the specific material employed, the amount of material present, and the size of the outermost perimeter of the recess 14 defined by end portion 19. Thus, it will be seen that the slug 16 may be formed to the desired shape without having to perform any machining operation, and without being limited to any specific initial shaping of the soft metallic material.
It is of course essential to proper operation that the slug 16 remain attached to the screw body 10. This may be accomplished in any convenient manner, as by providing a layer of material on the surface of the recess 14 which will bond the two operative parts 10 and 16 together. Thus, where as is preferred, the slug 16 is formed ofsilver solder, a conventional solder flux is applied to the surface of the recess 14 before the slug 16 is melted thereon.
FIG. 3 shows the set screw of the present invention in its operative environment. By way of illustration, a member 20 is shown carrying a cylindrical shaft 22 in a cylindrical passage 24. Within member 20 is a threaded passage 26 communicating with passage 24 and adapted to receive setscrew 8. Screw 8 is shown received in passage 26 so that tip 16 contacts shaft 23 at point 28. Shaft 22 is here shown purely by way of example, as cylindrical, but it should be noted that tip 28 will initially bear against the surface ofa member of any shape (other than a complementary concave surface) in point contact. After initial contact has been made, further turning of screw 8 will produce a slight deformation of the rounded tip 28 and a compressive settling of the tip material in conical recess 14. In this position screw 8 is adapted to firmly hold shaft 22 stationary with respect to member 20.
FIG. shows a setscrew of the present invention after repeated use in an environment such as that shown in FIG. 3. The concave configuration-of the tip 16 is due partially to deformation and partially to wear. It can be seen that the tip shape has tended to conform to the shape of the surface of shaft 24.
FIG. 4A shows a prior art construction of a setscrew of the type described. A cylindrical tip portion 30 of a synthetic material, such as nylon, is inserted in a cylindrical recess 32 in threaded shaft 34 having a tapered or bevelled surface 33. After repeated use in an environment such as that shown in FIG. 3, the tip material deforms to the shape shown in FIG. 48. Upon the application of axial compressive force the cylindrical tip bulges outwardly, as will any cylindrical member ofa deformable material. It will be readily apparent that this bulging effect once begun is self-perpetuating. Substantially all the deformation of tip 30 takes place exteriorly of the recess 30. Thus the material outside recess 30 is squeezed outwardly, weakening the material along a line separating the interior from the exterior portion. Continued use may result in complete severance of the exterior tip material from the portion within recess 32, whereby the setscrew is of no further use. Moreover, this severance is likely to occur while the screw is in use so that when the screw is loosened the severed portion may remain lodged against member 22, an obviously undesirable result.
It has been also found that the exterior material tends to develop cracks, such as 36 in FIG. 4B, emanating from the perimeter of recess 32. This effect is due to the localized compressive force exerted by the sharp edge formed at the intersection of the surface of recess 32 and bevelled surface 33. The portion extending beyond the perimeter of recess 32 may tend to sever completely from the tip material, again causing obviously undesirable results.
While the tip of a conventional set screw shown in FIG. 4A will show undesirable deformation after only a few uses, it has been found that the setscrew of the present invention can be used to lock and unlock two members over 100 times with a minimum of undesirable distortion.
Although all the reasons for the more desirable distortion pattern achieved with the setscrew of the present invention are not known, it is clear that the tip material used and its shape both contribute to the improved result. The following is offered as a partial explanation for this phenomenon.
As previously discussed, initial application of compressive force will occur by point contact at the center of tip 16. The tip, being constructed of a soft metal material, is readily adapted to flow and conform to the surface against which it is pressed. Thus, unlike a tip ofa material such as nylon, the initial deformation takes place substantially solely at the point of actual contact. That is, the compressive force exerted by member 28 has very little effect on tip material beyond the point of contact. While material is squeezed outwardly, this deformation is not harmful since the material in question is initially near the central axis of the tip and is not squeezed outwardly beyond the perimeter of recess 14 defined by end portion 19. The resulting flow pattern thus exhibits substantially very little outward bulging. Any bulging that does occur does not extend radially outwardly a sufficient distance to interfere with the insertion of threaded shaft 10 into member 20.
The present invention, therefore, comprises a setscrew which is easy to manufacture with a tip the shape and material of which exhibits substantially more durability than conventional setscrew tips.
While only a single embodiment of the present invention has been herein specifically disclosed, it will be apparent that many variations may be made thereto without departure from the scope of the invention as defined in the appended claims.
1. In a setscrew for holding a first member in substantially stationary relationship to a second member, comprising a threaded body adapted to be screwed into a threaded opening in said first member toward said second member, the improvement comprising said body having at a first end adapted to he directed toward said second member, a substantially axially extending recess, the sidewalls of which taper inwardly from said first end of said body, said recess being relatively shallow in comparison to the length of said threaded body, and a soft metal insert in said recess, fixedly secured to said body, and extending beyond the plane of said first body end, the extended portion thereof being convexly curved at least in the region of its farthest extending portion and being confined laterally within the limits of the periphery of said recess at said first end ofsaid body, said insert substantially filling said entire recess and being bonded to said body along substantially said entire recess, whereby said soft metal insert initially engages said second member in point contact thereby eliminating radial deformation beyond the outer periphery of said recess.
2. The setscrew of claim 1, wherein said soft metal insert is silver solder.
3. The setscrew of claim 1, in which said recess is substantially conical in shape.
4. The setscrew of claim 3, wherein said soft metal insert is silver solder.
5. The setscrew of claim 1, wherein said soft metal insert is formed of a single soft metal material, said soft metal material being exposed outwardly of said recess.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1046823 *||Feb 27, 1908||Dec 10, 1912||Western Electric Co||Electrical switch-contact.|
|US1581096 *||Aug 21, 1924||Apr 20, 1926||Howard S Barnes||Soft-nose screw|
|US2086221 *||Dec 10, 1934||Jul 6, 1937||Mallory & Co Inc P R||Contact assembly|
|US2747058 *||Aug 27, 1952||May 22, 1956||Ulanet Herman||Contact adjustment screws and contact assemblies|
|US3501993 *||Dec 17, 1968||Mar 24, 1970||Swenson Henry F||Setscrew with rotatable plastic end|
|GB466211A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5079508 *||Dec 17, 1990||Jan 7, 1992||General Electric Company||Electric power meter adjustment and indication method and apparatus|
|US5611325 *||Mar 27, 1996||Mar 18, 1997||Kudlacek; Donald S.||Archery bow stabilizer|
|US6440135 *||Dec 12, 2000||Aug 27, 2002||Hand Innovations, Inc.||Volar fixation system with articulating stabilization pegs|
|US6767351||May 30, 2002||Jul 27, 2004||Hand Innovations, Inc.||Fixation system with multidirectional stabilization pegs|
|US7320570 *||Feb 15, 2005||Jan 22, 2008||Czarnek And Orkin Laboratories, Inc.||Set screw with NiTi tip|
|US7425213||Nov 10, 2004||Sep 16, 2008||Depuy Products, Inc.||Method of endosteal nailing|
|US7527639||Jul 23, 2004||May 5, 2009||Depuy Products, Inc.||Fixation system with multidirectional bone supports|
|US7563263||Aug 24, 2005||Jul 21, 2009||Depuy Products, Inc.||Intramedullary fixation device for metaphyseal long bone fractures|
|US7645106 *||Sep 3, 2002||Jan 12, 2010||Mark Gordon||Cone-head thrust screw|
|US7695502||Sep 19, 2005||Apr 13, 2010||Depuy Products, Inc.||Bone stabilization system including plate having fixed-angle holes together with unidirectional locking screws and surgeon-directed locking screws|
|US7727264||May 9, 2003||Jun 1, 2010||Depuy Products, Inc.||Intramedullary fixation device for metaphyseal long bone fractures|
|US7780664||Nov 10, 2004||Aug 24, 2010||Depuy Products, Inc.||Endosteal nail|
|US7780711||Jul 23, 2004||Aug 24, 2010||Depuy Products, Inc.||Fixation system with multidirectional bone supports|
|US7857838||Sep 17, 2003||Dec 28, 2010||Depuy Products, Inc.||Anatomical distal radius fracture fixation plate|
|US7905909||Mar 20, 2006||Mar 15, 2011||Depuy Products, Inc.||Bone stabilization system including multi-directional threaded fixation element|
|US8057523||Jul 23, 2008||Nov 15, 2011||Warsaw Orthopedic, Inc.||Set screw with deformable member|
|US8403967||Jun 25, 2010||Mar 26, 2013||Biomet C.V.||Volar fixation system and methods of using the same|
|US8556945||Jun 1, 2010||Oct 15, 2013||Biomet C.V.||Anatomical distal radius fracture fixation plate with ulnar buttress|
|US8579946||Dec 20, 2010||Nov 12, 2013||Biomet C.V.||Anatomical distal radius fracture fixation plate|
|US9072558||Aug 14, 2013||Jul 7, 2015||Biomet C.V.||Distal radius fracture fixation plate with ulnar buttress|
|US9480512||Dec 10, 2013||Nov 1, 2016||Biomet C.V.||Volar fixation system with fixed-angle multi-hole drill guide|
|US9492213||Mar 8, 2013||Nov 15, 2016||Biomet C.V.||Volar fixation system|
|US9572609||Dec 10, 2013||Feb 21, 2017||Biomet C.V.||Method of using a volar bone plate on a fracture|
|US20040111090 *||Sep 25, 2003||Jun 10, 2004||The University Of North Carolina At Chapel Hill||Modification of percutaneous intrafocal plate system|
|US20040153073 *||Jan 22, 2004||Aug 5, 2004||Hand Innovations, Inc.||Orthopedic fixation system including plate element with threaded holes having divergent axes|
|US20040193155 *||Nov 29, 2003||Sep 30, 2004||Hand Innovations, Inc.||Fracture fixation plate with particular plate hole and fastener engagement and methods of using the same|
|US20040260292 *||Jul 23, 2004||Dec 23, 2004||Hand Innovations, Inc.||Fixation system with multidirectional stabilization pegs|
|US20040260293 *||Jul 23, 2004||Dec 23, 2004||Hand Innovations, Inc.||Fixation system with multidirectional stabilization pegs|
|US20040260294 *||Jul 23, 2004||Dec 23, 2004||Hand Innovations, Inc.||Fixation system with multidirectional stabilization pegs|
|US20040260295 *||Jul 23, 2004||Dec 23, 2004||Hand Innovations, Inc.||Fixation system with multidirectional stabilization pegs|
|US20050065520 *||Nov 10, 2004||Mar 24, 2005||Orbay Jorge L.||Endosteal nail|
|US20050065528 *||Nov 10, 2004||Mar 24, 2005||Orbay Jorge L.||Method of endosteal nailing|
|US20050159747 *||Mar 11, 2005||Jul 21, 2005||Orbay Jorge L.||Volar fixation system including guide|
|US20050180839 *||Feb 15, 2005||Aug 18, 2005||Czarnek And Orkin Laboratories, Inc.||Set screw with NiTi Tip|
|US20050187551 *||Jan 21, 2005||Aug 25, 2005||Orbay Jorge L.||Bone plate system with bone screws fixed by secondary compression|
|US20050191151 *||May 21, 2004||Sep 1, 2005||Doug Gethmann||Anti-rotation apparatus for use with threaded components|
|US20050240186 *||Mar 24, 2005||Oct 27, 2005||Orbay Jorge L||Bone fracture fixation systems with both multidirectional and unidirectional fixation devices|
|US20050245931 *||Jul 14, 2005||Nov 3, 2005||Orbay Jorge L||Volar fixation system|
|US20050277937 *||Jun 10, 2004||Dec 15, 2005||Leung Takkwong R||Bone plating system|
|US20050283154 *||Aug 24, 2005||Dec 22, 2005||Orbay Jorge L||Intramedullary fixation device for metaphyseal long bone fractures|
|US20060009771 *||Sep 19, 2005||Jan 12, 2006||Orbay Jorge L||Bone stabilization system including plate having fixed-angle holes together with unidirectional locking screws and surgeon-directed locking screws|
|US20060041260 *||Sep 30, 2005||Feb 23, 2006||Orbay Jorge L||Fixation system with plate having holes with divergent axes and multidirectional fixators for use therethrough|
|US20060100624 *||May 9, 2003||May 11, 2006||Orbay Jorge L||Intramedullary fixation device for metaphyseal long bone fractures|
|US20070088360 *||Mar 20, 2006||Apr 19, 2007||Orbay Jorge L||Bone stabilization system including multi-directional threaded fixation element|
|US20080226422 *||Sep 3, 2002||Sep 18, 2008||Mark Gordon||Cone-Head Thrust Screw|
|US20090192550 *||Apr 3, 2009||Jul 30, 2009||Ebi, L.P.||Bone plating system|
|US20100023063 *||Jul 23, 2008||Jan 28, 2010||Warsaw Orthopedic, Inc.||Set screw with deformable member|
|US20100241173 *||Jun 1, 2010||Sep 23, 2010||Orbay Jorge L||Anatomical Distal Radius Fracture Fixation Plate With Ulnar Buttress|
|US20100268283 *||Jun 25, 2010||Oct 21, 2010||Orbay Jorge L||Volar Fixation System And Methods of Using The Same|
|DE9209715U1 *||Jul 20, 1992||Nov 26, 1992||Langer, Georg, 5828 Ennepetal, De||Title not available|
|WO2016058677A1 *||Oct 7, 2015||Apr 21, 2016||KARL SCHÜSSLER GmbH & Co. KG||Clamping system|
|Aug 12, 1980||AS01||Change of name|
Owner name: BENRUS CORPORATION
Effective date: 19790828
Owner name: WELLS BENRUS CORPORATION
|Aug 12, 1980||AS||Assignment|
Owner name: WELLS BENRUS CORPORATION
Free format text: CHANGE OF NAME;ASSIGNOR:BENRUS CORPORATION;REEL/FRAME:003792/0790
Effective date: 19790828