Setscrew with rotatable plastic end

BACKGROUND OF THE INVENTION

Field of the invention ²⁵

The field of art to which this invention pertains is found generally in the class of Rod Joints or Couplings and in particular in the subclass of “collar, pulley or lever and shaft” and even more particularly in the subclass en- 30 titled “setscrew, pin or bolt.”

Description of the prior art

In the use of setscrews for retaining members on shafts, which shafts may be plain, with keys or with threads, it has been found highly desirable in most instances to use a soft face on the retaining member so that a burr is not raised upon the engaged member. In anticipation thereof, there are setscrews available wherein a nylon inserted tip is mounted in the end of the body of the setscrew. However, as far as is known, these nylon inserted tips have been a force fit in the end of the set screw body. When such a setscrew is turned tightly against a curved surface or against a threaded surface, the nylon end or soft insert, as it is rotated with the threaded body, is abraded and becomes mutilated or destroyed until it is rendered unsuitable for re-use. In certain of the presently commercially available setscrews, the setscrews are made from tubing and have a swaged drive socket formed in one end. The other end of the tubing receives and retains the soft tip which is a plug of nylon or other resilient material. This tip or plug, as the setscrew is turned forwardly, expands outwardly and rearwardly toward the retaining body, and is often cut when the setscrew is advanced against a curved surface or some other surface in which there is an irregularity. The abrading action providing the tendency of the fixed plug insert to be mutilated or destroyed is avoided in the instant invention.

BRIEF SUMMARY OF THE INVENTION

A solid setscrew body has its end shaped so as to receive and retain a nylon plug or a like resilient, partially resilient or otherwise soft member, which member is rotatable on or in the end of the screw body as the screw is advanced forwardly into retaining Or locking engagement. In particular, the setscrew rotatably retains a nylon member which is mounted in one of several socket designs as shown in the drawings. Each socket provides a γθ shoulder or face against which the thrust of the softer member may be received as the screw is advanced.

INTENT OF THE DISCLOSURE

Although the following disclosure offered for public dissemination is detailed to insure adequacy and aid in understanding of the invention, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how it may later be disguised by variations in form or additions of further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirements of pointing out the parts or improvements in which the inventive concepts are found.

There has been chosen several embodiments of a solid setscrew body with a rotatable protruding resilient end as adapted for use in retaining hubs and the like to shafts both threaded and unthreaded. These embodiments have been chosen for the purposes of illustration and description as shown in the accompanying drawings wherein:

BRIEF DESCRIPTION ON THE DRAWINGS

FIG. 1 represents a setscrew partly in section and showing a plastic insert seated within a shallow recess in the end of the setscrew and with the metal shoulder portion which retains the plug turned inwardly to slidably engage the plastic plug;

FIG. 2 represents a sectional and fragmentary view of the end of a setscrew similar to that of FIG. 1, however, the metal retaining shoulder portions of this embodiment extend outwardly from the threaded end of the setscrew with the outer end portions turned inwardly to slidably engage the plastic plug;

FIG. 3 represents a sectional and fragmentary view of an end of a setscrew wherein a nylon cap is pressed over the protruding end of the setscrew, the cap having inturned engaging lips acting as a retaining collar for the cap;

FIG. 4 represents a sectional and fragmentary view of an end of a setscrew wherein the nylon tip or plug has an additional plastic or metal ring mounted on the inner end of the plug to provide a shoulder member disposed to fit within a formed recess in the socket of the body of the setscrew;

FIG. 5 represents a sectional and fragmentary view of an end of a setscrew having a socket with ridges formed in the sidewall, the inserted plug also is provided with corresponding ridges formed in its sidewall;

FIG. 6 represents a sectional and fragmentary view of an end of a setscrew wherein the resilient plug is retained by means of a small cross pin carried in the body of the screw;

FIG. 7 represents a sectional and fragmentary view of an end of a setscrew wherein the end and socket are formed with a contour adjacent an undercut recess;

FIG. 8 represents a sectional and fragmentary view of an end of a setscrew which is a modification of the setscrew of FIG. 7 wherein a small chamfered seat is adjacent an undercut recess and forms the major portion of the plug retaining means;

FIG. 9 represents a sectional and fragmentary view of an end of a setscrew wherein the retaining portion of the rotating plug is forced into an undercut recess in the end of the screw body;

FIG. 10 represents a sectional and fragmentary view of an end of a setscrew wherein the plastic member is a cap member fitted over an outwardly expanded protruding end portion of the setscrew;

FIG. 11 represents a sectional view of a plastic plug or rotating member prior to its insertion into the socket of a setscrew, and

FIG. 12 represents a sectional and fragmentary view of an end of a setscrew wherein the plug member of FIG. 11 is mounted in the socket of a solid setscrew body.

3,501,993

This ring is shown as being formed with a tapered socket and is preferably retained on a like-formed end of the insert 54 in a pressed fit condition. The ring member 56 is at least slightly resilient and may be of soft metal or of plastic. The recess 52 at its main outbore portion is a few thousandths of an inch smaller in diameter than at the enlarged inner portion 53 so that this enlarged recess portion acts as a retainer for the ring 56 to prevent the plastic insert 54 from being withdrawn from the recess 52 after the insert has been rotatably assembled in the recess 52 of the body 50.

It is contemplated that in the assembly of the resilient member 54 in the enlarged portion 53 of the recess the ring 56 is slightly compressed as it is pushed through the reduced diameter portion of the socket 52. After ring member 56 enters the enlarged portion 53, it expands to provide a sliding and retaining fit in the enlarged recessed portion 53.

DESCRIPTION OF THE SETSCREW OF FIG. 5

Referring next to FIG. 5, there is shown a setscrew body 60 having a bore 62 wherein small ridge portions 64 are formed in the wall and extend inwardly of a common diameter of the bore. A plastic insert or plug 66 having a shouldered diameter portion 68 slightly smaller than the ridge portions 64 has this portion 68 pushed into the socket 62. The outer wall of the diameter portion 62 engages these inwardly disposed annular ridges or rings 64 and cut small mating grooves in the plastic surface as the setscrew body 60 is turned. These grooves, as they are cut in the plastic insert, slidably engage these rings to provide means for rotatably retaining the insert 66 in the socket.

DESCRIPTION OF THE SETSCREW OF FIG. 6

Referring next to FIG. 6, there is shown a setscrew body 70 having an end recess 72 formed therein. A plastic insert 74 is mounted in recess 72 and has an arcuate groove 75 formed in the sidewall and at a determined 40 distance from the inner end 76 of the insert. A locking pin or dowel 78 is mounted and retained in a transversely drilled hole in the body of the setscrew. This pin 78, as it is inserted in the drilled hole of the body, tangentially enters groove 75 so as to rotatably retain 45 the plastic body 74 in recess 72.

DESCRIPTION OF THE SETSCREW OF FIG. 7

Referring next to FIG. 7, there is depicted a setscrew body 80 having a recess 81 formed in the center of the -θ end of the body. This recess has a reduced shoulder portion 82 formed at the outer end of said recess. Adjacent to and outwardly of this recess 81 there is formed a V-shaped groove 83 in the face or end of the setscrew body 80. A plastic plug member 84 is preferably made 55 of nylon and has a contoured face including a complementary V-shaped protrusion sized to mate with the V-groove 83. This plug is mounted onto the end of the setscrew body 80 with the V-groove portions of the plug member and screw body end mating with each other at 60 groove portion 83. An inwardly extending stem portion 85 of the plug is locally undercut and is sized so as to be rotatably retained by shoulder portion 82. The end of the stem has an enlarged diameter portion 87 sized so that this plastic shoulder is rotatably retained 65 in the recess 81 of the setscrew body 80.

DESCRIPTION OF THE SETSCREW IN FIG. 8

Referring next to FIG. 8, there is depicted a setscrew body 90 formed with chamfered shoulder 92 terminating 70 at an undercut recess 94. A stem portion 95 of a plug member 96 is sized and adapted to seat in and be retained in recess 94. The inwardly sloped face surface 97 of the plug member is contoured to mate with and to seat upon chamfer 92 and is rotatably retained by the stem portion 75 95 in the recess 94. The retention of the plug is by means

In the following description and in the claims, various details will be identified by specific names for convenience; these names, however, are intended to be generic in their application. Corresponding reference characters refer to like members throughout the several figures of _gthe drawings.

The drawings accompanying, and forming part of, this specification disclose certain details of construction for the purpose of explanation of the broader aspects of the invention, but it should be understood that structural jq details may be modified in various respects without departure from the concept and principles of the invention.

DESCRIPTION OF THE SETSCREW OF FIG. 1

Referring now to FIG. 1, it is to be noted that a 15 hollow head setscrew body 20 has a shallow recess 22 formed in its end. In this recess a nylon insert or plug 24 is disposed to be mounted. The inner face 25 of this nylon insert or plug 24 is flat and rests upon a like surface formed in the recess 22 of the setscrew. Adjacent the inner flat surface 25, the sidewall of the plug is provided with a shallow groove 26 into which a small inwardly formed ring portion 28 of the setscrew extends. This ring portion 28 acts as a retaining collar so as to prevent the insert 24 from falling out of the recess 25 22 while permitting the setscrew body 20 to turn in a threaded hole.

In the assembly of the setscrew of FIG. 1, it is contemplated that the shoulder portion 28 may be made as an upstanding or outwardly extending portion of the end 30 face 29 of the setscrew body 20. After the insert 24 has been mounted in the recess 22, this shoulder portion 28, by means of a seating or swaging tool or by means of a spinning operation, is displaced into the position shown in FIG. 1. 35

DESCRIPTION OF THE SETSCREW OF FIG. 2

Referring next to FIG. 2, there is shown a setscrew body 30 having a recess 32 formed therein. This recess has an upstanding shoulder portion 34, which shoulder portion, as the setscrew body is formed, is made as an outstanding ring with a substantially straight bore and flat bottom. An insert 36, preferably of nylon and having a shallow groove portion 37 formed in its sidewall, is mounted in this socket with the inner flat face 38 resting on the flat bottom of the socket. To retain the insert 36 in the socket 32, the upstanding ring portion, as in the setscrew assembly of FIG. 1, is forced inwardly by means of a seating tool or by spinning so that the ring portion 39 acts as a collar which enters and slidably engages the recess 37 of the insert 36 to rotatably retain this insert in the socket.

DESCRIPTION OF THE SETSCREW OF FIG. 3

Referring next to FIG. 3, there is shown a setscrew body 40 which has its end formed with an extending shouldered end 42 which has an enlarged outer diameter 43. A nylon or like plastic cap 44 is sized to slide over the enlarged portion 43 so that a flat inner base 45 will seat on a like flat end of shouldered portion 42. After the flat base is brought into engagement with the end of shouldered portion 42, a shoulder portion 46 is caused to be formed in cap 44 by being swaged inwardly by means of a clamping tool or by spinning to cause the shoulder 46 to slidably engage a groove in shouldered end 48. The shouldered portion 46 formed on the plastic cap 44 rotatably retains this cap on the extending shouldered end 42.

DESCRIPTION OF THE SETSCREW OF FIG. 4

Referring next to FIG. 4, there is shown a setscrew body 50 formed with a recess 52 having an enlarged portion 53 formed at the inward end of said recess. A plastic insert or plug 54 which is preferably of nylon has a ring member 56 mounted on the inner end thereof.

3,501,993 withdrawal of such a setscrew from a hub or the like raises no problems as the plug does not turn until free of any inhibiting contour or engagement.

Terms such as “up,” “down,” “bottom,” “top,” “front,” “back,” “in,” “out,” and the like are applicable to the embodiments shown and described in conjunction with the drawings. These terms are used merely for the purposes of description and do not necessarily apply to the position in which the setscrews and their rotatable plastic ends may be constructed or used.

The conception of the rotatable and retained plastic plug in combination with a solid screw body and its. many applications is not limited to the specific embodiments shown and protection is sought to the broadest extent the prior art allows.