US2012842A - Flexible shaft - Google Patents

Description

Aug. 27, 1935. J, B. WHITTED FLEXI BLE SHAFT Filed March 28, 1934 5 'fara/f j M 0 J Y/w` am. mwwmwhwm@ @www w Patented Aug. 27, 1935 STATES;

i Y f aolasjziz' *FLEXIBLE sim-Fr i. .'John Whitted, Evanston,- lll., assign(jr'J `1,0:v Y

` `Stewart-VlarnerY Corportcx'r,` Chicago, lvIll?, a y corporationiof Virginia' f 'hisfinventionrelates to improvements in flex ible` shafts of the type", which may lbe used, for

example;-,as a `flexible drive shaft for ai Windshield .z Mylinventionis animprovement over theflexvible driver shaft for `windshield wipers shown in my prior application Serial No. 692,911, led October 9, ,1933;

It is an object of my invention toprovide a i exibleshaft in which the rotatable core .will rim:

silentlywithin theilexible sheath thereof.

It is.. further an object ofv my invention to provide afrotatablecore for a flexible shaft comprising aninner core ofV tightly twisted. strandsv of e steel wire enclosed Within afabric coveringy and to provide a flexible metallic sheath for housing the rotatable core.; i, l l

A still further object of my invention is to provide a flexible shaft which is lubricated within its sheath by utilizing as a rotatable core a Figure l is an elevation of one end of the rotatable core and the drive'tip therefor, showing, in section, a portion of the flexible sheath and a connected ferrule;

Figure 2 is a similar .view of the other end of the flexible shaft;

Figure 3 is a section `on the plane indicated 40 3-3 in Figure 1;

Figure 4 is a section on the plane indicated 4 4 in Figure 1;

Figure 5 is a section on the plane indicated 5-5 in Figure 1.

The flexible inner core I0 is made up in the conventional manner of tightly twisted strands of steel wire. Over this metal core I0 is tightly. WovenV a fabric covering or jacket I2, composed of strands of cotton thread. This jacket I2 may be woven in any well-known manner by the use 'of a looming machine. Although this fabric covering or jacket I2 is woven Very tightly about the steel core IIJ, it would nevertheless tend to ravel and come loose if suitable steps were not taken to hold the fabric in place. I provide af square section, las lindicated fat I v.in Figur brass4 sleeves I4, one ateachfendofftheilexible` shaft. The sleeves I4 are rst, slipped over the;

ends of the fabric covered rotatable core; The` I fabriccovering I2 isitherr pushed.backtoexpcgfseJ the endsof the steel core I0. Each: end of.the ;l 5

steel corel is thenA placed` ina' die and-'pressed 110.1l

Apdriveytip or driving member 4.I8 is-,connected toene endof the steelfcoreandra driven lmemberv 20 is attached to the other end ,o f,y thek steel corel',

Each ofthesedrive ltipspr membersgjj andJIl v Y isfprovidedwith a socket ,22;to. receive ythesguarell endvIBi-of. the metal core I-.I)."Eachl of, the tips isy rigidly "securedito'the metal core IIJ beine crimped in placeyas indicated. crimped; squared section, 2,41 and asclearly sho Fig-'ure 5. y'-Ehepfebri .covering I 2;, `has been pushed back, is now returned to place and the excess material cut off so that each end 26l of the fabric covering I2 is adjacent tothe end 20 of the corresponding drive tipV I8 or 20. Bach of -l the brass sleeves I4 is then moved until it is close to the drive tip. The brass-sleevesv I4 may then be crimped tightly to the fabric covered metallic core, as shown by the crimped squared 25 vsection 28. As shown, thebrasssleeves I4 are crimped in place in such a manner as to con` form to the shape of the ysteel coreythe ends of which have been previously pressed ina die to a squared section. Thus, portions of the sleeves 30 I4 ysurround the cylindrical portion of. the core I0 and may retain the cylindrical shape, as clearly shown in the drawing. This mayV assist in maintaining the core concentric with respect to the sheath. By this method of construction the 35 drivetips are tightly secured to the metaillic core and the fabric covering is tightly held in place against unraveling'.

The rotatable core is enclosediwithin a flexible metallic sheath 30 which, at its ends, is con-'40 y graphite oil or any other form of lubricant would `50 be suitable. The fabric covering will absorb the lubricant and therefore the shaft will bel properly lubricated without using excessive amounts of grease and oil which may ooze through vrthe sheath or joints therein. When the lubricated 55 core rotates within the sheath for a period of time, the fabric impregnated with lubricant becomes glazed and presents a very smooth surface to the interior ofthe sheath, thus friction losses are very low. Moreover, the fabric effectively prevents a Whirring or rattling noise which is frequently present in flexible shafts of this type in whichza fabric. jacket is not provided for the metallic core. l i K v The use of a flexible sl'iaft'asl spec'ically disclosed herein is described in more detail in my. prior application, Serial No. 692,911, led Oc"` tober 9, 1933, whereinthe core not only. rotates WithinV the sheath but is Vadapted for slidable movement to control a clutch at' one end ofthe flexible shaft.

I claim:

1. A flexible shaft assembly "comprising a kro-` tatable flexible shaft and a non-rotatable flexible l metallic sheath, said rotatable exible shaft com? prising i a -metallic core with a lubricant-impregnated e fabric .covering thereon' andV rotatable therewith.- v 'l I 2, A flexible shaft assembly comprising a rotatable flexiblel shaft anda non-rotatable'flexible'` metallic sheath, said Arotatable flexible shaft cornprising acore composed of tightly twisted strands of steelwire and a tightly Woven lubricant-ini# v pregnated fabric 'coveringl on -said metal core and rotatable therewith. T v

3.-A flexible shaft assembly comprisinga nonrotatable flexible-metallic `sheath' and a flexible rotatableshaftfsaid flexible fshaft comprising a steel core and a tightly Woven lubricant-impreg- T natedfabric covering drive tips fixed to the ends ofsaid steel core, thefabric covering on said steel core extending adjacent -to said drivetips, a pair "thereto, a pair of sleeves through which the end`s-.,'offsaid fabriccovered core extend, said sleevesy being fixed inposition to hold the fabric in place by being clampedA to the square Asections of said core adjacent the tips.

5. A flexible shaft assembly comprising a nonrotatable exiblemetallic sheath and a rotatable flexible shaft, the rotatable flexible shaft comprising a steel core and a lubricant impregnated fabric cover VWoven on saidsteel core, drive and driven tipsfixed directly.v to the ends of said steelcore, thevfabric coveringf'being previously cut away to permit connection with the coreqand sleeve members receiving the'fabric coveredco're and fixed thereto to hold the fabric covering inv place at its ends and'prevent unraveling. f 6. lA exibleshaft assembly comprising-a ex iblerotatable shaft composed of a core of tightlyv twisted strandsofsteel Wire Vfor transmitting the driving torqueand a tightly woven lubricantimpregnated fabric coveringfab'out said tightly twisted strands and rotatable therewith `and af non-rotatable vflexible metallic sheath for housing the lubricant-impregnated fabric covered metallic shaft.` Y

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