US2743637A

US2743637A - Torque wrench adapter for power tools

Info

Publication number: US2743637A
Application number: US476805A
Authority: US
Inventors: Ernest L Redmon
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-12-21
Filing date: 1954-12-21
Publication date: 1956-05-01
Anticipated expiration: 1973-05-01

Description

May 1, 1956 E. REDMON TORQUE WRENCH ADAPTER FOR POWER TOOLS Filed Dec. 21, 1954 INVENTOR Ernest Z. 18612772022 BY M ATTORNEY TORQUE WRENCH ADAPTER non POWER TOOLS Ernest L. Redmon, Columbus, Ohio Application December 21, 1954, Serial No. 476,805

3 Claims. (Cl. til-52.4)

This invention relates generally to torque wrenches, and more particularly to an improved torque wrench adapter for use in detachably coupling socket-type wrench heads of various sizes to an associated hand-held power tool, such as an electric motor driven hand drill.

In the past, numerous types and constructions of torque wrenches have been proposed for use in imparting tightening rotation to nuts or similar fastening devices, particularly in operations where it is desirable that such nuts be tightened upon an associated bolt or stud only through the application of a predetermined torque force. However, previous torque wrenches of this type of which I am aware are generally characterized by a relatively high degree of mechanical and structural complexity and consequent high cost.

It follows, therefore, that the primary object of my invention is to improve generally upon previous torque wrenches by providing a relatively structurally simple, yet mechanically efiicient torque wrench adapter for hand-held power drills which is operable in combination with such drillsto receive various sizes of socket wrench heads and impart rotational torque forces thereto of variable and adjustable magnitude, whereby to insure the tightening of an associated nut positioned in the socket wrench head to a given tension upon an associated bolt or stud.

Another object of this invention is to provide a torque wrench adapter for power driven hand drills which is relatively compact in construction and comprised of but few and relatively simple mechanical parts, and which may be easily connected with an ordinary power driven hand drill to detachably receive varying sizes of socket wrench heads and easily adjusted to impart various predetermined torque forces thereto.

A still further object of the invention is to provide a torque wrench adapter of this type which is composed in the main of external, readily adjustable, and unmachined parts of rugged construction, and which may be manufactured at comparatively low costs, andwhich, at the same time, possesses the necessary mechanical efiiciency to enable the same to effectively accomplish its intended purpose.

' For a further and more complete understanding of the present invention and the various additional objects and advantages thereof, reference is made to the following description and accompanying drawing, wherein:

Fig. 1 is a longitudinal vertical sectional view, partially in elevation, showing my improved torque wrench adapter in operative relation to an associated driving tool and socket wrench head;

Fig. 2 is a transverse vertical sectional view taken along the line 22 of Fig. 1; and

Fig. 3 is a perspective view of the adapter.

Referring now to the drawing, my improved torque wrench adapter comprises a driving shaft, generally indicated at 5, which is formed at one end with a straight bit-like extension 6 adapted to be clamped within and drivingly received by the chuck portion 7 of an ordinary electric motor driven rotary hand drill or tool, indicated generally at8, after the manner of a standard drill bit. The shaft 5 is further formed with a screw-threaded intermediate portion 9, and terminates at its opposite end in an integral, relatively diametrically enlarged, disk-shaped head 10. Preferably, the bit-like extension 6 of the shaft 5 is smooth and unthreaded as shown in the drawing, but if desired, the shaft may be threaded throughout its length, with the exception of the head, without adversely affecting the operation of the adapter, as will be hereinafter more fully explained.

Enclosing the disk-shaped head 10 of the shaft 5 is a generally cylindrical clutch drum, indicated in its entirety by the reference numeral 11. The drum 11 is composed of a hollow, open end, cup-shaped section 12 and an annular end wall 13 which is welded, or otherwise suitably and permanently secured, as at 14, to the section 12 after the head 10 is positioned therein. The end wall 13 of the drum is formed with a central bearing opening 15 through which the shaft 5 extends, and which defines on the end Wall an inner, flat, annular surface 16 arranged for frictional engagement with the complemental flat annular surface 18 formed on the inner side of the head 10 of the shaft 5.

The cup-shaped section 12 of the drum includes an integral, relatively reduced, axially extending driven shaft 19 which terminates at the outer end thereof in a square, multiangular, wrench head-receiving extension 20. Advantageously, the extension 20 may be suitably recessed to receive and retain a spring-pressed hall 21 which extends partially outwardly from one of the sides of the extension 20 to frictionally engage one of the wall surfaces defining a square, multiangular chamber 22 formed in a socket wrench head 23. The wrench head 23, as shown in Fig. 1, constitutes a standard socket-type wrench head formed with a multiangular nut-receiving socket 24 in the forward end thereof. It will be understood that wrench heads 23 having varying sizes of nut-receiving sockets may be used interchangeably with the present torque wrench adapter in accordance with the size of nuts desired to be tightened during work operations.

Rotatably carried on the shaft 5, adjacent the end wall 13 of the clutch drum, is an annular bearing washer 25, The washer 25 is abutted on one side thereof by an end of a relatively heavy coil compression spring 26 disposed in encircling relation to the intermediate screwthreaded region 9 of the shaft 5. The opposite end of the spring 26 is abutted and held by an adjustable stop nut 27 which is threaded onto the intermediate region 9 of the shaft 5. A lock nut 28 is also threaded on the region 9 of the shaft 5 and, when tightened down against the stop nut 27, serves to hold the latter against accidental backing-off movement on the shaft.

As will be understood, the spring 26.is normally maintained under compression between the stop nut 27 and the bearing washer 25, and under such condition causes the inner wall surface 18 of the head 10 of the shaft 5 to be drawn into tight frictional engagement with the complemental inner surface 16 of the end wall 13 of the drum 11, whereby to effect a yieldable frictional driving engagement between the shaft 5 and the drum l1 and a wrench head 23 disposed on the extension 20. The tension upon the spring 26, and consequently the force tending to hold the head 10 in engagement with the drum 11, may be adjusted within relatively wide limits by simply adjusting the position of the stop nut 27 axially on the intermediate threaded region 9 of the shaft. For example, in nuttightening operations where it is desired to impart relatively high torque forces to the work, the stop nut 27 is tightened down on the shaft 5 toward the head 10 thereof to compress the spring 26 to a maximum. Cons 3 versely, where; relatively light torque is required, the nut 27 may be backed off on the shaft 5 to a point where the spring is only lightly compressed, thereby decreasing the forces tending to hold the head in tight frictional engagement with. the end wall 1 of theqdrum.

In operation, the bit-like shank 6 of the adapter is tightly clamped in the chuck of the hand. drill 8 in order that the adapter may be rotated at high speeds upon energization of. the motor of the drill or tool 8. The stop nut 27 is then adjusted on the screw-threaded. region. of the shaft 5 to a position to impart the desired tensionupon the head 10 of the shaft in. accordance withthe torqueforce desired tov be imparted to anassociated nut to bev tightened The position of the stop-nutv 27 ;upon the shaft 5 for any desired torque outputmay: be easily predetermined by first testingtheadapter with a suitable tudihal adjustment on the intermediate region of said shaft; spring means carried on said shaft between said stop means and the end wall of said clutch drum for bolding the annular inner surface of said disk head in frictional, non-slipping,torque transmitting engagement with the annular inner surface of the end wall of said clutch drum, said head slipping and turning relative to said drum when predetermined torque forcesare applied to the interengaging surfaces thereof; and a second shaft carried torque-measuring; gauge, and, if desired, theintermediate screw-threaded region of. the shaft 5 may be suitably indexed'or graduatedsoas to provide ready visual reference forthe setting; of the stop. nut, 27 in, adjusting the torqueoutput. of the adapter. After setting of the stop nut 27-, a suitable size wrench head 23 is selected in accordance withthe size of nut to be tightened, and the Wrench head snapped, onto the extension of the adapter. The wrench head is then placed over the nut to be tightened and the motor of; the hand drill 8 is cnergized=, whereupon the component parts of the adapter and the nut to be tightened are rotated in unison until the resistance to further tightening of. the nut reaches or exceeds the predetermined torque output of the adapter, at which time the drum 11, shaft 19, and wrenchheadZZtare stopped from rotating and the head 10 of the shaft slips and rotates within the drum 11.

It will thus be see'n that the present invention provides a mechanically efficient, structurally simple, and inexpensive torque wrench adapter for power tools which is characterized by its rugged construction, ease of assembly and adiustability, and ready accessibility to parts for adjustment, repair, or replacementpurposes. 7

While I have shown and described. indetail a single preferred embodiment of myiinventiomit will beunder stood that the same is susceptible to certain modifications as to details of construction and design without departing, from the spirit of the invention or the scope of the following claims. a V

I claim: g

1 A torque wrench adapter comprisinga shaft formed at one end for insertion within the chuck of a rotary handtool and having an intermediate, externally screwthreaded' region thereon, said shaft at the opposite end thereof being provided with a' diametrically enlarged disk head having a flat,annular, inncr surface; a hollow. clutch drumvofnon-adjustable, unitary construction rotatable on and enclosing the disk head of said shaft and having an end wall formed with an opening through which said shaft extends, said end wall having a flat, annular, inner surface arranged for frictional engagement with the annular inner surface of the disk head of said shaft; stopmeans threadedly carried in an open position for'longibyand extending axially outwardly fronmsaitl cl'utuzhrhumv at the end thereof opposite the said end wall and formed at the outer end thereof with a multiangularextension to drivingly receive a socket-type wrench head.

2. A torque wrench adapter as defined in tuna i and.

wherein said stop means comprisesr apair of internally threaded nuts adjustable on the intermediate threaded region of said first-named shaft to vary the tension of said spring means'and thereby the force holding the annular inner surface of. said. disk head inv frictional engagement withthe inner surface ofthecnd wall of clutch drum.

3.. A torque wrench adapter comprising a first. shaft formed at one end with a bit extension fordriying connection with a rotary power tool, said shaft; furtherincluding an intermediate, externally screwfthreaded regionand a. diametrically enlargcdheadat theend thereof opposite to the bit extension, the head, of first shaft beingv formed. with a fiat, annular, inner surface;

a generally. cylindrical drum of nonradjustable, unitary construction. rotatably carried on and'enclosing the head of said first shaft, said: drum havinga fiat, annular, end

wall arranged for frictional, power-transmittingengage-.

ment with the flat, anuulan, inner surface of, said head; a second shaft formed integrally with said drum extending axially and longitudinally outward from the end thereof opposite said flat, annular, end wall, said. second shaft terminating in a multiangular extension for the. detachable reception of a, driven wrench head; openly. disposed, longitudinally adjustablq stop. means threadedly .disposed around, the intermediate portion of said. first shaft; and coiled, compression.type, springmeans carried; on: said. first. shaft, said. spring meansv bearing, at one end against said stop means. and, at its opposite, end. against the end wall of said: drum, whereby to. urge the. flat, annular, inner surface of said head normallyv ms power-transmitting, frictional. engagement. with the an nular end wall of said drum, the adjustment ofsaid stopv means on, said first shaft serving to vary the compression.

of said spring means and. the frictional forcesfdeveloped. thereby in holding; theinterrengaged wall surfaces. 'of.

the head and drum in power-transmitting engagement,

whereby to enable said head to turn relative to said drum when predetermined forces restraining the drum against rotationv are encountered.

References Cited in the'file of this patent UNI ED STATES PATENTS 23-35574 Thompson et al. Nov. 30, 1943' 2 ,471, 14 Gilman May 31-, 1949