US1438648A - Set screw - Google Patents

Description

B. F. JACOBS.

SET SCREW.

APPLICATION FILED AUG.4. 1921.

1A38,64& Patented Dec. 12, 1922.

IN VN TOR.

Patented Dec. l2, i922.

BENJ'AJEEIN F. JACOBS, 0F BOSTON, ABBACHUSETTS.

ear scam.

Application 111ml August t, 1921.

To all whom it 'ma. concern:

Be it known that BENJAMIN F. JAooBs, a citizen of the United States of America and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Set Screws, of which the following is a specification, reference being had to the accompanying sheet of drawing, forming part thereof.

My invention relates to set-screws and the like, and has for its object to provide a set-screw with an automatic self-locln'ng means, which normally serves to anchor the set-screw in set position when driven home and otherwise serves to free the set-screw when being backed out from the aforesaid set and anchored position.

Another object of my invention is to provide a self-lockin set-screw with an independent projectlng purchase peg in the bottom thereof, which is .so designed as to permit of its being frictionally held in working relation with the set-screw for couplin the peg therewith to form .a unit device therefrom.

Still another object of theinvention is to provide a peg tip set-screw which comrises the combination of a split screw member and a wedging peg, which in the first instance serves to radially expand or contract the split section of said screw member, and in the second instance serves to provide a purchasing element for the set-screw.

To accomplish the aforesaid objects, ll employ a split-screw member which is designed with a central, longitudinal bore in the lower end thereof, said bore being countersunk to provide a flared or tapered section at the entrance thereof, together with a peg or plug which is designed with a tapered head adapted to wedge and spread the split section of said screw member as the same is being driven home, and an expanding stem section adapted to fit the bore of said screw member and frictionally hold said peg secured thereto.

Other objects and advantages of the in vention will be gathered from the description following herein and considered in connection with the accompanying drawing wherein the invention is shown embodied.

The terms employed herein are used in the generic and descriptive sense to designate the elements illustrated, and are therefore not intended as terms of limitation.

Serial No. @9376.

In order to illustrate my invention, but

without being limited thereto, I have shown an embodiment thereof in the sheet of drawing wherein:

Fig. 1 represents an elevational view of my type of peg-tip set-screw; Fig. 2 represents a sectional view show- 1n r the set-screw in operation; th 1g.t 3 represlfnts a pvirt sectional view of e se -screw s owln t e e or In frictlonally held therein p g p g Fig. 4 represents an elevational view of the peg or plug removed from the set-screw; Fig. 5 represents an enlarged sectional view of the pegend of the set-screw, showing the set-screw before being driven home andabout to make purchase with the shaft; Fig. 6 represents a similar view to Fig. 5, but shows the set-screw driven home;

F g. 7 represents a sectional view taken on line 77 on Fig. 3;

accompanying Fig. 8 represents a sectional view taken on line 8-8 on Fig. 4;

end of the set-screw; and

Fig. 10 represents the same view as Fig. 9, but shows the peg removed from the screw member.

Like numerals refer to like parts throughout the several views of the drawing.

The numeral 20 represents a machine screw which is more particularly known and referred to as a set-screw; it being under stood that while I have shown the same provided with a square-shaped wrench head my lnvention applies as well to all other shapes and types of set-screws. The working-end 21 of the set-screw 20 is split longitudinally, as the slot 22 indicates, which provides for a radial spread to the set-screw, as will be hereinafter more fully explained. 23 represents a central bore or chamber which is provided longitudinally in the setscrew and which may be blind, as the drawing indicates, or may pass clear through the set-screw, according as may be desired. Said bore at the working end of the set-screw is countersunk to provide, the tapered 0r flared seat section 24.

25 represents a peg or plu which is rovided with the purchasing ilead or tip 26. the flared or conical shoulder section 27, the stem 28 which fits the bore 23 of the set-screw, and the expansion or clutchin elements 29. The conical shoulder section 2 of said peg or plug 25 is preferably inclined at an angle approximating, but greater than, the angle of slope to the countersunk section 24 of the set-screw bore, asthe drawing indicates. I

30 represents a collar which is provided with the radial tapped hole 31 for rece 1v1ng the set-screw 20 therein, as shown in Fig. 1;

the set-screw serving to securely couple said collar 30 with the shaft 32.

Having thus described the parts, of my invention in detail, the same is employed as follows: First, it will be noted that theszg is slidably fitted in the chamber provi therefor in the screw member 20, said peg I being held therein by means of the ex ansion or clutching elements 29 which notionally expand against the walls of the bore 23 and hold the eg coupled with the screwmember against ropping out therefrom, as

mi ht otherwise be possible. v T %ith the peg thus coupled with the screw member the 'two forma unit set-screw which may be emplodyed wherever set-screws are ordinarily use I i The peg serves as the purchaslng element of the set-screw, as may be understood, for the head 26 of the peg is forcibly'brought up against the shaft 32 as the set-screw 1s is held against accidental backing out, which is a most common and troublesome occurrence with the ordinary types of set-screws.

Incidentally the employment of the peg or plug, as herein described, provides for a much'more effective purchasing-feature for the set-screw inasmuch as ',tl ie take-up between the peg and the screw member. when driving the set-screw home, provides for a grip or purchase against the shaft which is not possibly attainable in the ordinary setscrew which is designed to bottom directly on the shaft. This bottoming of the screw member directly on the shaft has its disadvantages and often is responsible for upsetting the end of the set-screw, which in many instances makes it impossible to remove the set-screw fromv the member carrying the same. Forcing a set-screw under such circumstances usually results in the breaking off of the head of the set-screw and requires boring or drilling out of the set-screw.

With my type of set-screw herein described, the occurrence of the upsetting fea- 'ture above referred to is impossible, and

thus one of the most objectionable features of the' common .types of set-screws is elimi-.

nated. Then again it must be apparent that in removin my type of set-screw the mere I 29 thereof will normally hold the peg coupled with the screw member so that the setscrew, as a unit is always intact and ready for service. e

It will thus be noted that the set-screw ma be designed to serve any purpose for whlch set-screws are ordinarily intended; that any type of head may be employed in connection with the pegor plug; that the construction of the .WlthlIl described setscrew is simple and may be produced at a very low cost; that said set-screw possesses features which are not possibly included or attainable in the present types of set-screws; and finally that said set-screw yields results which are both beneficial and advantageous in the machinery line. Y

While the preferred embodiments of my invention have been described in detail, it will be understood that I do not wish to be limited to the articular construction set forth, since various changes in the form, material, and in the details of construction may be resorted to without departing from the spirit and scope of the invention, or destroying any of the advantages contained in the same, heretofore described and defined in the subjoined claims.

Having thus described my invention in detail, what I claim as new is:

1. The combination of a split set-screw. having a central and flared chamber in the working end thereof; and a peg slidably fitting said chamber and adapted to wedgedly spread the split portion of the set-screw for radially expanding the same and provided with spring means integral therewith for frictionally holding said peg in coupled relation with said set-screw.

2. The combination of a split set-screw having a longitudinal chamber therein provided with a countersunk seat section at the 'mouth thereof; and a peg having a purchas- I chamber of said set-screw to frictionally hold said peg in coupled relation therewith.

3. The combination of a set-screw having a longitudinal split thereinand a longitudinal countersunk bore at the working end thereof, and a peg provided with a projecting, purchasing head, a wedging shoulder adapted to wedgedly engage with the countersunk bore of the set-screw for radially spreading the split section thereof, and a centering stem provided with expansion elements adapted to frictionally engage the peg with the set-screw for frictionally coupling the two together.

4. A set-screw peg having a purchasing head, a wedging shoulder, and a centering 10 stem provided with integral expansion elements adapted to frictionally engage the peg with the set-screw.

In testimony whereof, I aflix my signature this thirtieth day of July, 1921.

BENJAMIN F. JACOBS. Witness:

DAVID LIOHI'ENSTEIN.

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