US2696397A - Turnbuckle - Google Patents

Description

Dec. 1, 1954 J, H, OOTH 2,696,397

TURNBUCKLE Filed July 20, 1950 design,

.,6 6, TURNBUCKLE Application July 20, 1950, Serial No. 174,871 1 Claim. (Cl. 28,7.60)

This. invention relates, to an improved type of turn buckle for adjustably attaching two connecting members.

More specifically, the invention relates to an improved turnbuckle of generally tubular construction havingv an expanded turnbuckle barrel and which taining clamps on each end in. properlongitudinal position on the barrel. The invention also includes the method of making the turnbuckle barrel.

According to this invention a generally tubular turnbuckle barrel, which may be formed by rolling a-blank of sheet metal into the desired tubular shape, isformed with a central portion of slightly larger diameter than the. end portions. The endportions are internally, threaded with right-hand threads wihin one end portion and left-hand threads within the other. Slots are. formed axially inwardly through the wall of the barrel from each end thereof and extend almost to the central portion. Clamping rings are inserted over the ends of the barrel and have bolts extending across the slots in the barrel. When connecting members have been threadedly inserted into the internally threaded ends, the clamps can be tightened on the barrel ends serving to squeeze the ends of the barrel tightly about the attached ends of the connecting members. Tabs are pressed out of the metal of the barrel at either side of each clamping ring at points substantially diametrically opposite the slots, and these tabs serve to retain the clamps on the ends of the barrel even when the clamps are loosened to permit rotation of the turnbuckle barrel about the ends of the connecting members.

The turnbuckle of the present invention, having an increased diameter central portion, has several distinct the conventional turnbuckle of this type.

barrel most likely to fail under a heavy load. By increasing the diameter of the unsupported central portion the section modulus is thereby increased and thus the tube is strengthened. In addition, due to the increased inside diameter of this central portion, the internal threads cut at the ends do not extend into the central portion, leaving it free from weakening notches which make for high stress concentrations and consequent y failure under load. Furthermore, the turnbuckle need have threaded sections as the minimum required threaded engagethe larger central portion provides an unthreaded for adjustment between the ends of the connecting members. In the conventional in order to provide the necessary adjustment length, the thread must be substantially longer than the minimum required engagement.

an object of this invention to provide a nlarged diameter central portion with increased section modulus and a smooth unthreaded inner surface in the central portion.

A further object of the invention is to provide a tu buckle barrel with an enlarged central portion with internally threaded end portions of minimum required threaded lengths.

A further object of the invention is to provide a turnbuckle assembly having clamping rings at either end and having tabs pressed outwardly from the metal of the turnbuckle barrel on either side of each of the clamping portion of the United States Patent O 2,696,397 Patente D ,95

rings for retaining the clamping rings on barrel.

Another object of the invention is to provide a turn: buckle barrel having an enlarged central portion which maybe easily and, inexpensively formed by rolling a piece of flat metal sheet into the desired shape.

Still another object of the present invention is to pro-v vide a novel turnbuckle barrel of increased strength without necessitating a substantial change in existing methods of manufacture and without using a heavier gauge of metal sheet.

Other and 7 parent to those skilled in the art from the following d tailed description of theannexed sheet by; way of preferred example only, bodiment of thepresent invention.

On the drawings:

Figure 1 is a perspective view of a substantially. flat metal blank as used in forming the turnbuckle barrel of the present; invention with a formed barrel shown, in dashed outline superimposed on the blank;

Figure 2 is a plan view of a turnbuckle barrel according to the present invention;

Figure 3 is a side elevational sectional view of the barrel shown in Figure 2',

Figure 4 is a side elevational'view of a turnbuckle according to the present invention with clamping rings thereon and connecting members inserted in the end portions; and

Figure 5 is a reduced size and, elevational view-taken along l n Vi -T f Figure 4.

As shown on the drawings:

the turnbuckle 10 has a downwardly offset central section 11 of greater width than end sections 12 thereof. Inclined flanges 11a connect the central portion or kerfs 13 are pressed angularly downwardly from the metal of the blank, two in each end section 12, the tabs lying substantially along a single longitudinal line. The longitudinal side edges of the end sections are recessed or indented along their length as at 14 and have inturned rounded outer ends 14a and outturned rounded inner ends 14b.

In Figures 2, 3, 4 and 5 is shown a turnbuckle barrel 15 which is formed by rolling the blank 10 of Figure 1 into tubular shape. The longitudinal edges of the central section 11 are abutted firmly together as by welding 16. The central section 11 of the blank 10 forms a diametrically enlarged central portion 17 of the barrel I 15. End portions 18 are formed by the end sections and have slots 19 therein formed by the recessed edges 14. Each slot has an outwardly flared rounded entrance mouth 19a formed by the ends 14a and a rounded botformed by the ends 14b.

The ends 18 and central portion are joined by the sloping shoulders 17a formed from the flanges 11a. Retaining lugs 20, diametrically opposite to the slots 19, are formed by the tabs 13 of the blank 10.

As best seen in Figures 2 and 3, the end portions 18 have internal threads 21, the threads in one end portion being right hand and those in the other end portion being left hand. The threads 21 are preferably formed after the weld 16.

It should be noted that the inside diameter of the central portion 17 is greater than the major diameter of the internal threads 21. Hence, the inner surface of the central portion 17 remains smooth and unnotched and consequently is free from any points of unnecessary stress concentration.

Referring to Figure 4, clamping rings 22 are disposed over the end portions 18 of the barrel 15 and are prevented from axial movement thereon by the lugs 20. The rings 22 have outturned clamping cars 23 at either side of their longitudinal slots 24. Bolts 25 are inserted through holes in the ears and extend across the slots 24. Nuts 26 are threadedly inserted onto the ends of bolts 25 and have lock washers 27 thereunder.

Connecting members 28 and 29 having externally threaded portions 30 and 31 respectively are threadedly metal blank inserted into the end portions 18 of the barrel 15 to eninsertion of a threading tool, resulting in further increa:

gage with the internal threads 21 formed therein. in case of manufacture. Easily formed lugs serve to It It is apparent from the structure described that rotatain clamping rings on each end of the barrel so that th tlon of the barrel 15 in one direction will serve to furrings will be retained in proper axial position on the end ther insert both of the connecting members 28 and 29 of the barrel and will not slip off the ends when loosene into the barrel thereby tighte ing the connection. Conto allow insertion of the connecting members.

versely, rotation of the barrel in the opposite direc- It will be understood that modifications and variation tion will serve to loosen the connection. When the demay be effected Without departing from the scope of th sired relationship between the connecting members 28 novel concepts of the present invention.

and 29 has been achieved, the nuts 26 are tightened down 10 I claim as my invention:

on the bolts thereby tightening the clamping rings 22 in a tubular clamping structure, a tube comprising 2 about the end portions 18. Thus, the walls of the end single curled sheet, of substantially uniform thickness portions 18 will be pressed firmly against the threaded having its central portion of wider extent than the em sections 30 and 31, thereby effecting a tight, non-rotating portions thereof and depressed radially and cylindricall connection between the connecting members 28 and 29. 15 outwardly with longitudinally juxta-opposed edges ex- From the above description it will be understood that tending and ofi'set circumferentially beyond the oppothe present invention provides an improved turnbuckle site and remaining end portions of the tube and joined having a non-threaded, diametrically enlarged central together leaving gaps in the end portions longitudinally portion which serves to increase the strength of the aligned with said joined edges, said depressed central barrel Without materially changing the conventional 0 portion at each of its ends having an annular reinforcmethod of forming such turnbuckles and without increasing shoulder merging into the adjoining tube end portion ing the gauge of the metal used in forming the barrel. adjacent the inner end of the associated gap in the end It can be readily seen that the turnbuckle barrel is eX- portion as Well as adjacent an end of the joined edges. peditiously (but not necessarily) manufactured by rolling a pregioluslyhformed sltibstafntially flat bliifilk intg tlhe 5 References Cited in the file of this patent proper tu u ar s ape. W en ormed in suc a tu u ar shape internal threads are easily cut in the ends of the UNITED STATES PATENTS barrel, and since the enlarged central portion has a Number Name Date larger inside diameter than the major diameter of the 339,534 Dickson Apr. 6, 1886 threads, each of the threaded portions may be of mini- 0 390,992 Stillman Oct. 9, 1888 mum length for proper engagement while still allowing 935,659 Johnson Oct. 5, 1909 for proper adjustment within the unthreaded central por- 935,660 Johnson Oct. 5, 1909 tion. As a further result of the increased diameter cen- 1,148,041 Minkler July 27, 1915 tral portion, threading of the end portion may be easily 1,326,008 Tarbox Dec. 23, 1919 accomplished without precise control over the depth of 2,526,470 Gauthier Oct. 17, 1950

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