US2159354A

US2159354A - Torque wrench

Info

Publication number: US2159354A
Application number: US171596A
Authority: US
Inventors: Alien I Dunn
Original assignee: Cedar Rapids Engineering Co
Current assignee: Cedar Rapids Engineering Co
Priority date: 1937-10-28
Filing date: 1937-10-28
Publication date: 1939-05-23
Anticipated expiration: 1956-05-23

Description

Patented May 23, 1939 PATENT oI-Flcs TOBQUE WRENCH f y Allen I. Dunn. Cedar Rapids, Iowa, assigner to Engineering Cellar Rapids Oompany, Cedar Rapids, Iowa, a corporation of Iowa Application October 28, 1937, Serial No. 171,506

Claima.

This invention relates to wrenches. and more particularly to a wrench for indicating the amount of force or torque applied to the handle in rotating or attempting to' rotate a nut or the 5 like engaged by the wrench.

This application is a continuation in part of my application Serial No; 136,048; flied April l0, 1937.

It'has been found. for instance, in the tightening of nuts on cylinder heads of internal combustion engines, or in assembling precision devices such as air-craft engines and the like, that it is very desirable to tighten the nuts and bolts of such devices to certain known degrees.

It' is a general objectl of my invention to provide a mechanical torque measuring wrench in which deformation of the parts of the wrench is employed in indicating the torqueapplied to the wrench.

I0 It is also an object of my invention to provide a wrench of the above character in which the parts are protected from mechanical injury.

Another object of my invention is to provide a torque indicating wrench of extremely simple 25, construction and in which there is a minimum of friction. 1

Another object of my invention is to provide a torque indicating wrench of increased accuracy n over devices known to the prior art.

' Another object of my invention is to provide a torque indicating wrench in which the operator, in using the wrench, grips the wrench at one point only so that the readings are always accuu ratek ad correct. f

Another object of my invention is to provide a torque indicating wrench in which the torque measuring instrument is located in a position where it is out oi' the way when engaging the n vrk and where it is protected from mechanical 1 ury.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specification,

wherein is disclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made therein as fall within the scope oi' the appended claims,

50 without departing from the spirit of the invention.

In the drawing:

Figure 1 is a plan view of a wrench constructed according to a preferred embodiment of 55 my invention.

Figure 2 is a view in vertical section through the wrench shown in Figure 1, and

Figure 3 is a view in horizontal section through the wrench shown in Figure l.

A device constructed according to a preferred l embodiment of my invention includes a head Il, in which a ratchet shaft or socket shaft II is received, and this head serves also as a means for receiving a hollow handle I2 at right angles to the socket handle shaft II. The opposite end l0 of the handle I2 is received in an indicator base Il. A grip lia comprises an extension of the indicator base Il and an indicator Il is received in the indicator base L.

In the form of the device here shown, I have u incorporated a ratchet mechanism in the head III. This ratchet mechanism includes a ratchet wheel Il having square teeth II. The pawls Il and Il are received in bores 2| and 22 which are formed in outwardly flared portions IIa and Ilb so of the head I0. These pawls are so arranged that when one of the pawls is in engagement with a tooth as indicated at 2l, the other pawl 24 is riding on top of the tooth. Thus, half steps of ratchetlng are secured. 25

The pawls I 8 and Il are biased inwardly by means of springs 26 and 2'I which bear against the pawls Il and I9 and against caps 2l received in the cylindrical bores 2| and 22. Pins 29. having knurled heads SI, have a threaded engage- 30 ment with the pawls II and I9 and the pawls may be rotated by means of these knurled heads 2| so that the ratchet wheel It may be rotated in either direction as desired by oscillating the handle I2 or may be locked with reference to the 3- head I0. A squared end Ila is provided on the end of the ratchet shaft II to engage sockets in accordance with the usual practice.

A split sleeve l2 is received within the handle I2 within the head I0 and this split sleeve is o anchored to the large end of a tapered shaft J3, this shaft 3l being of course, located within the hollow handle I2. 'I'he shaft is tapered so that a maximum of clearance between the shaft and handle is afforded at the free end of the shaft. The hollow handle I2 is made' of resilientmaterial, as will hereinafter appear. One locking means for locking the split sleeve 32 with reference to the shaft ll is a set screw and ball indicated at Il.

When the set screw n in the head III is screwed tightly into place against the hollow handle I2 it not only holds'that member in place but defor'ms it enough to grip and hold rigidly the split sleeve 32 and the shaft I3. 55

videdwitna'sput misma 'cess-to me cnambenlmy be ima g -transversebore 4| which passes through-the indicator base il. The bore 4i may be closed by the threaded plug'4l. v

A movable cylindrical portion |44 of vthe indicator I4 is re'ceived within the bore 4I` and is .'held in place by va ball and spring inserted through the base il and abutting against the.

cylindrical portion I4a. Thesprlng tensionl may be changed by means o! va screw which holds the spring and ball in place, thus allowing the indicator to be set at aero, all in accordance with the usual practice. The shell I4b of the indi- Y cator abuts against the outer face of the base il. The gear rack 81 engagesa pinion 42 located -on the pinion shaft 4I and the pinion shaft 43 is rotatably mounted in bearings 44.

"An indicator needle 4l is secured to the outer end of the shaft 44 vand of course rotates over the .dial 4l in accordance with movement of the free v end vof theshaft 33 with reference to the indicator basey I I. A hair'spring 4l is provided to 1 vtake up any lost motion or backlash between the pinion 42. and rack 31. l

It -may readily be understood that iffthe sockv"et handle lia is engaged on a socket and the socket engaged to a nut, bolt or the like and pressure applied to the'handle lia. the flexible handle i2 willmove with Vreference tothe shaft. 3l. If the direction of the force applied is atI right angles to the axis of thesocket handle Il, j the relative movement of the handle with referen'ce to the shaft will cause thegear rack 31. .to rotate thepinion' 42to cause movement ofv 'the indicator needle 45 over the dial 41.

.a nut. In lcalibrating the dial 41,v the distance The grip Ila is' so formed and arranged that it constitutesthe handiest place for the operator to grasp the wrench in tightening or loosening from the central portion of the grip Ila to the centerv line of the socket handle Il may be considered the lever arm for rotating the handle.

-The dial may4 then be calibrated with markings Lcorresponding to the number of inch-pounds-applied at the grip Ila, the number of inches be- 1 ving considereda's the distance from the center ofthe grip to the axis of the handle Il. 'Obviously the dial may be calibrated in any suitable :manner as in inch-pounds, foot-pounds, centimeter-grams or any other units of measure--l g ment.

new

set forth in th'eappendedciaims. my invention:

shaft to theindicating means for driving indicating means. v g

l il.` In a torque indicating wrench, `\a head, a

viiexible hollow handle 'xed to the head, a grip' member having an opening transversely therethrough, the grip member being ilxed to the handle, an indicating device mounted within-y the opening, a Ashaft coextensive with the handle and located within the handle, means for rigidly engaging the shaft at the head end of the wrench and a rack and pinion for 'driving the indicating devicefromthe free end of the shaft. l

3. In a torque indicating wrench, `a head, a flexible hollow handle secured lwithinthe head, a grip member at the other end of vthe hollow handle, an indicating means mountedwithin the grip member, a shaft coextensive with the handie and secured within the handle and head, and

means for operatively connecting' the indicatin means with'the free en d of the shaft. l,

v4.'In a torqueindicating wrench. a head, a

nut engaging means on the head, a nexible hol,

lowhandle `engaged to the head, a sleeve within the hollow handle and the head, a shaft engaged within the sleeve, a grip member mounted on the opposite end of the hollow handle'from the head, an indicating means mounted within the grip member, and a rackand gear for driving the indicating means from the free end of the shaft. l

5. In a torque indicating wrench, a head, a

iiexible hollow handle member fixed-to the head,

an instrument base on the flexible handle member opposite to the head, a shaftrigidly engaged 4within the head and extending through the handle, an indicating means mounted in the instrument base, and geared means for transmitting relative movement between the free ends of the shaft andl handle to. the indicating means to indicate the relative degree of vsuch movement.

I. DUNN.