US2401876A - Tensiometer - Google Patents

Description

`lune 11, 1946.

A. L. MARKER E- r AL TENSIOMETER Filed May 23, 1944 #Lgf/9T L. Nwe/Ele @dE/mfc WEE/865K@ INVENTOR.

A? r TORA/Ey.

Patented June 11, 1946 Y TENSIOMETER Albert L. Marker and Emric W. Bergere, San Diego, Calif.

Application May 23, 1944, Serial No. 536,999

This invention relates to tensiometer.

.In the construction and maintenance of various equipment, and particularly airplanes, it is necessary to rig them with cables, which are maintained under a desired tension and are used for the purpose of bracing the structural parts of the ship or for operating controls. In each instance it is necessary to maintain the cables, guy wires and the like, under a predetermined minimum tension. Various types of tensiometers have been designed for this purpose. These instruments are for the most part expensive and must be carefully handled in order to prevent injury and misadjustment of the parts. At the present time there is in use a type of wrench which applies a predetermined amount of torque to an object to be rotated. It has been found desirable to provide a convenient piece of equipment with which' such a wrench may be used to perform the functions of a tensiometer and to make it possible to quickly and accurately ascertain whether or not a cable has been drawn sumciently tight to be under a predetermined minimum tension. It is the principal object of the present invention, therefore, to provide a tool having adjustable indicating means thereon and elements to engage a cable, and which tool may be easily assembled with av` torque set' wrench whereby the Wrench may function to indicate when a minimum desired tension has been imposed upon the cable.

'Ihe present invention contemplates the provision of a unitary tool having a handle and gripping means thereon for engaging a cable at iixed points on one side of the cable and a movable element for engaging the cable at an intermediate point upon the opposite side of th'e cable, said element being capable of adjustment for cables of dierent diameters and being provided with means whereby a set torque wrench may be assembled temporarily with the movable element to make a tension test;

The invention is illustrated by way of example in the accompanying drawing in which:

.Figure 1 is a view in side elevation showng the cable engagng tool with which' the present invention is concerned and indicating the application of a set torque wrench with relation thereto.

Fig. 2 is a View of the tool taken edgewise to show the handle and the oiset position of the plate carrying cable engaging means.

Fig. 3 is a fragmentary view showing a portion of the tool as seen from th'e opposite side indicated in Fig. 1, and more fully disclosing the xed and movable cable engaging elements.

5 Claims. (Cl. 73-144) Referring more particularly to the drawing, I0 indicates a handle. This handle is formed integral with a body plate II here shown as having an arcuate portion I2 and a transverse portion I3, which extends laterally of the longitudinal axis of the h'andle and at opposite sides of said axis. The upper edge of the plate I I is bent at right angles to the body of the plate, as indicated at I4, and provides a stiffening land mounting member which is also at right angles to the longitudinal. axis of the handle. Extending through the portion I3 of the plate adjacent the ilange and near opposite ends of thefplate are pins I5 and IG, respectively. These are disposed with their axes parallel and normal to the plane of the plate. Mounted upon the pins are saddle blocks, I1 and I8, respectively. Each saddle block is formed with an arcuate groove I9 in its lower face to receive a cable 20, which is to be tested. The saddle blocks h'ave an upper flat face ZI against which a leaf spring 22 rests.` This spring is secured to the under face of the ange I4 by a bolt 23. Disposed in the same plane with the blocks I'I and I8 and substantially midway the distance between these blocks is a saddle block 24 which has an arcuate grooved upper face 25. This engages the cable 20 substantially midway between the centers of the blocks Il and I8 and rests against the diametrically opposite side of the cable 20 from that against which the grooves I9 of the blocks I1 and I8 rest. The lower saddle block 24 is mounted upon a pivot pin 26 having an axis parallel to pins I5 and I5. The pin 26 extends through a slot 21 in the plate I3 and is carried by the free end of a pressure lever 28. The pressure lever 28 is carried by a fulcrum pin 29 extending through the plate I3. A lever extension 39 is formed integral with the lever 28 and is disposed at a suitable angle thereto. This extension is formed at its free end with a squared opening 3|. The squared opening 3| receives a squared pin carried by the head of a set torque wrench, indicated by dotted lines at 32. This wrench embodies the principle disclosed in U. S. Patent No. 2,172,561 issued to Frederick P. Kruse on September 12, 1939, and its details are shown generally in Patent No. 2,365,486 issued to Harry P. Morris on December 19, 1944. It Will be understood that in this type of wrench an adjusting plug 33 creates a desired compression of a spring carried Within the handle of the wrench and tends to hold the head of the wrench against rotation with relation to the wrench handle and body until a predetermined resistance is offered to the head of the wrench, whereby the handle sizes of cable 23 which are to be tested, and when the cable 2E) is unflexed the top saddle blocks I1 and I8 and the lower saddle block 24 will be disposed so that their arcuate faces Willccontact the cable. 31 should be in register with the graduation on the scale 3S agreeing with the diameter 'oft-he cable 20. In order to provide adjustment or the pointer to cause it to register with the graduations of the scale 39 a bracket 4I) is carried onthe leg of the pointer 31 and istted with an adjustingfbolt GI, The .bolt I engages upperY face :l2 of the pressure lever 28 and will vride therealongas the lever 28 swings.

In .operation of thepresent .invention the testing Vtool is constructed and assembled asshown in Fig. 1, vafter which the squared V pin carried bythe head of the wrench .32 is lpositioned within the squared `opening `3I vat the `end of the 'lever extension 3D. When the set torque wrench 3.2 has .been assembled with the testing tool, as shown inFig. 1, the ,handle AI'Il ,of the testing tool and `the 1handle .3,6 .of the .wrenchwill be substantially parallel. 'The handle of the Wrench may be swungoutwardly to ,lower .the lower saddle.

block 24 so thai-,the -cable .20 .to be Ktested ,may be .laid in the .grooves I9 vof the upper .saddle blocks Il and J8, `after which .the Ahandleof .the wrench 32 .may .beswungin Ythe ..direction..,of ,the arrow. a shown in Fig. .1. This willbring the arcuate groove .25 of thefsaddle blocklll .in `contact with theY cableZIl. Y'.Uhe tensionof thecable may ,then-be tested. It .should be explained-that the set .torque wrench has A.been adjusted by v.manipulationof .the plug33so that Vthe Ispring within the handleof thewrench willbeunderfa .desired tension, ,as ,indicated'by .the pointof register of the .indicator .pin .3,5 with ,the-calibrations of the scale 33. Thus, .assuming that each calibration indicates ten pounds, it wvillbe evident that by When this takes place the pointer springof the .tool theindicating pin 35 wilLmove along the -slotted lopening 35 toward the Zero point.

In performing a testing 'operation it will be assumed, by way of example, that the -wrenchis set fora torque .load of sixtyfpounds. The wrench is then applied .to the lever arm 3l) andthe -handle of the wrench 3.2 and the "handle I0 of the testing tool then are forced toward each other. As this -takes place torque is imparted Ythrough the wrench 32 to the free end of the lever extension .33. This tends to :swing the pressure lever .2:8 vin the direction `of the Aarrow b and forces the .saddle ,block 24 Vagainst the cable -23 atfthe opposite sides of the IPOints of contact of the -cable with .the saddle blocks `I'l and I8. The

result will .be that the tension of the cable 2.9.

will tend to resist the force of the saddle .block 24 ,as thesaddle V191001124 moves to ilex thelength of cable forminga span between the saddle bloclis 4 I1 and I8. As the tension of this length of cable resists movement of the saddle block 24 the lever 28 will be held against rotation on its pivot 29, and the wrench body and handle 32 will be caused to rotate around the head of the wrench which will be held immovable by the squared pin ex-V tending into the opening 3| of the lever extension 3B. As the wrench handlev rotates the mechanism within the wrench `will force .the index pointer35along '.the slotted opening 3.6and toward the zero graduation. Assuming that the 'pointer 35 reaches the zero graduation a force of sixty pounds will have been applied to the free end-of the lever extension 30 and a suitable force vwill .have been applied to the saddle block 24 :dueto the leverage existing between the lever arms 30 and 28. If the pointer 35 moves from its set positionto the zero graduation on the scale -34 this will indicate that the cable 20 is under a minimum tension represented by the ln-l itially set position of the pointer 35.011 the wrench 32, After the ltest has been made kthe wrench can be removed so that it is ready for any other use desired, and due ,to'the fact that the 'testing toolis rugged in construction it may be vplaced away without fear of vaccidental damage and without the parts losing their adjustment.

Some ,types of set torque wrenches may have an element in them which tends to break when a predetermined amount of torque force 1hasioeen applied to the torque Wrench and isbeing resisted by an element rotated by v the wrench. When this type of wrench is usedthe desired'ten; sion test may be made inthe same manner as' herein described, with vthe exception 'that'jwhen the tension of .the cable resists apredcte'rmined amount .of forcethewrench will break and indicate that the vcab'lehas at Aleast the f desired amount vof tension. l i It will ,thus be .seen that the testing 'toolhere disclosed .is simple in .construction ,and or 'a design wh'ich makes it N.possible for ,the 'tool vtolte easily adjusted for yuse. in testing the ltension of cables of 4various diameters, the said r,tool being operable in connection with: a torque .setjw-rench whereby expensiveV and delicate testing equipment is eliminated. Y

While we have shown the ,preferred form lofour invention as .now known to us., it will -be understood that various changesinaybe made in com.-` bination, construction and arrangement oi parts by .those skilledin theart, without departing. from the spirit of our inventionas claimed.

Having' thus described our invention` .what .we claim ,and .desire to secure by Lettersglatent is.:-

'l. vlVleansi-or testing a cablesaid means 4acting in combination with a.v set torque wrench,.andin-l said xed elements, a bell crank pivotally mounted on the frame `of said 4tool and-oarryingthe movable element at the .fend of :one .lever 'armthereof, the end -of the vopposite leve-r arm :receiving a rotatable member .ofa set torque wrenuh,

whereby when the handle o the'w-renchz-.andthetool are forced toward .each other the ,movable 2, A tensiometer vattachment ,tor a -setltorquez therewith, a pair of relatively xed saddle blocks spaced from each other on said plate to engage one side of a cable to be tested, a movable saddle block to engage the opposite side of a cable to be tested, a bell crank carrying the movable saddle block at the end of one of its arms and being pivotally mounted upon said frame plate, the opposite arm of the bell crank being designed to receive engaging means from the head of the set torque wrench, whereby when an effort is made to force the handle of the tool and the wrench toward each other there will be a tendency to swing the bell crank on its pivot and force the movable saddle block against the cable.

3. The structure of claim 2 including a graduated scale carried upon the body plate, and o.

6 pointer pivotally mounted upon the body plate to swing over the graduated scale and being moved with the movable saddle block.

4. The structure of claim 2 including a graduated scale carried upon the body plate, a pointer pivotally mounted upon the body plate to swing over the graduated scale and being moved with the movable saddle block, and means for adjusting said pointer with relation to the scale and the movable saddle block.

5. The structure of claim 2 in which the body plate is oset with relation to its handle, whereby the handle of the Wrench will be in substantially the same plane as the handle of the tool.

ALBERT L. MARKER. EMRIC W. BERGERE.

Images