US1439769A - Driving key and process of fitting the same - Google Patents

Description

Dec. 26, 1922. 1,439,769

Y R. A. SMITH. DRIVING KEY AND PRocEss oF FITTING THE SAME.

FILED .JULY 6, 1922.

64 J2 0^. a? 1NI/ ToIg. if@ fg?, J7 j y@ 0/56 56 /53 sofr c I BY A TTORNEY.

unite rer criss.

nonnivr ii. siiirii, or inaiiwaii, New JERSEY. iissien'on To siiii'rii asiinnniii., or MAHWAH, ivnw innsnr, A corairrivniisiiir consis'rineor sein ROBERT A.

SMITH- AND JOHN J. SERRELL.

DRIVING KEY AND JPRCESS OF FITTING THE SAME;

iippiicetion ined iuiy e, i922. semi Nq. 573,195.

To all liv/"mm z'mcn/ concern:

Be it known that LRonrirr A. SMi'rHya citizen of the United States, and resident of Mahwah, Bergen County, State of New Jer,- sey, have `made a certain new and useful Invention Relating .to Driving` Keys and Processes of Fitting theSanie, ot which the following is a specilication, taken in connection with the accompanying drawing, which forms part of the same.

This applicationisa continuation in part of iny copending application Ser. No. 484,094 filed July l2, 1921that is, this case contains subject matter taken therefrom. f f y This inventionrelates especially to driving keysand `processes of ltting thesanie .for coupling shafts to other parts off niachinery, the keys being provided with cut- .a somewhat diagrammatic way a number of ,illustrativekeys for usein such processes:

l isa ksectional view showing the inse that when the key is forcibly driven into the usual rough key wayin the shaft and other cooperating parts these cutting edges cut or finish one or more of thel inner surfaces of the vkey way to .such an extent that the corresponding face of the key is torcedor wedged against the saine to give a wedgingclosely iitting and secure driving connection between the parts. Especially where the key is to be withdrawn at relatively frequent intervals'it is preferably thoroughly greased or oiled adjacent the cutting faces before it is drivenr whichfpi'events oritiinimixes the ahrasionior undesirable cutting action which might otherwise occur between these strongly engaging inetal inccs.` it is usually desirableto-Aiorin such keys ot hardened and tempered steel at least adjacent the head or forward cutting portion which may be advantageously ground to size after such heat treatment or other isc accurately shaped so as to 'forni the cutting or portions lwhich preferably have adjacent chip retaining recesses especially where several cutting edges are formed on the` saine tace ott the key so that each cutting- "edge can successively Afinish or cut oli portions ot the key way 'face to more accurately iinish `the saine. lt is also advantageous'to guide or align the head oi the key while yit is heing driven and for this purpose a somewhat narrower orsma'ller forward guiding align- `ing portion may bey formed ahead of the main cutting edges or portions so that the Lkey is automaticallyy guided or aligned as it is hammered or forced into the key way. Itisalso desirable in inanyrcases to adjust the` effective length of the key by cutting )oit or removing partsofthesame before 4oi' after it is driven into place and for this purpose a severable reark or driving4 end may be formed on the key end of relatively sott material which may be cut ofi' by hack saws.

letc.,l or by having a hard driving end formed with breaking nicks or notches en tending more or less yaround vit at the desired intervals so that portions may bev broken oii'f eitherbefore or after the key is driven.

In theaccompanying 'drawing showing in of suoli' .a key; and '1 Fig; 2 is an endview thereof. Fig. 3 is an enlarged topi view' greater detail and other illustrative forins of keys.

partly in section showing the pkey construction in F ig. 7 is a side view showing anotlieriorin i i of key and n Fig. 8 is a corresponding end view.

Fig; 9 is a sidev view showing still another illustrative construction, and y AFig.V l0 is an end view thereof. f As indicated in Figs. l and 2,*the ordinary `rough slotted or milled keyways 11, i4 may be' formed in any. desired'way in the cooperating part'ssuch asthefshai't l2 and the flange andrcou'plingY nieinberl for example. .The self-fitting or cutting key -l which may have oiie or more cutting edges such as 2, on at least one of the driving "faces oi the Ain'en'ibe'is uiider service conditions; and it desired, both of these opposite driving faces ciittinge`olg`g'es'-` 2., 3 softhat when the key is forced in'to lthisslightly under-sized keyway,

these edgesai'itoinatically cut their own slot of such size as to accurately accommodate. or

'it 'the body@ of 'the key. coiirse'the'end l kev such as its'u er or lower notched edges v Y C i `iiiay be formedw'ith `one or more of such 10 oi the key may vbe beveled if desired so to be driven home byu hammer or other means. lt is also desirable to form such self-fitting cutting keys of tool steelwor still better of special tough strong steel, which is heat treated to harden and toughen the bodyI of the key and leave the cutting edges in most effective condition. In many cases it is desirable to preliminarily or roughly form these cutting edges and then after hardening and tempering the key, to grind or otherwise finish or straighten the key body, and in some cases to grind the cutting edges in proper relation thereto to get best results.

As is indicated in Fig. 3 one or more cutting edges such as 2, 3 may iny many cases be `advantageously formed on both of 'the opposing driving faces of the key, and each of these successively acting cutting edges may be slightly larger so that each of them may remove a few thousandths of an inch from the corresponding face or edge of the keyway as the key 'is driven home. It is sometimes advantageous to have the final cutting edge such as 3 formed so as to take only a light out, this material being accommodated in a chip retainer recesssuch as 6 formed adjacent this cutting edge and eX- tending inward, so as to give ample room to produce the desired cutting angle for this edge. In some cases also one or morecutting edges such as 5 may be formed on one or both of the other faces of the key besides the driving faces thereof, although it is usually better to have at least one of these inner and outer key faces flat sopas to act somewhat `more efficiently as a guide and aligning surface when the key is inserted. ln some cases also the key body may have a wedging action if the inal cutting edge is slightly smaller than the adjacent driving face of the key, and as shown on an exaggerated scale in Fig. 3 the width of the portionsy 8 of the key adjacent theV cutting edges 3 may be slightly smaller y.than

.the corresponding driving faces 9; and the inclined. or curved portion 7 `joining these' tivo faces may have a few thousandths of an inch or` less difference so as tose'cure the desired tightness of drive it depending of coursefon the size of key employed.

Fig. 4 shows another illustrative key 21 'which may have the opposing driving faces l'oiined with cutting edges 1.9 adjacent the front end or head of the key; and in some enses also a forward aligning guiding portion 18 having somewhat rounded or drilled edges of slightly less width may be forined ahead of these lateral cutting edges so as to guide the key when inserted and-during its first cutting movements. This guiding portion may be formed in some cases with forward cutting edges 17 if desired, and lintermediate cutting edges v16 may be formed kon this guiding portion `preferably on the uplaagjes per face thereof, The upper face ofi the key proper may also be .formed with a cutting edge 20 preferably longitudinally displaced from the lateral cutting edges 19 and these cutting edges may advantageously be formed with cuttingvangles of about 750 as is indicated in connection with the cutting edges 19. Suitable chip retaining recesses such as 23 may be formedadjacent any or all of these cutting` edges. It is in many cases desirable to have the length of these selffitting keys adjustable so that any suitable 4length can be cut or broken oft' from the standard length keys manufactured and sold; and for this purpose it is often advantageous to form angular breaking notches or nicks such as 22 extending more or less completely around the key at intervals of a quarter or afhalf inch apart adjacent its rear driving end where it is struck by the hammer driving the key into the keyway. Such weakening breaking nicks or angular recesses or notches make it possible to break oit one or more sections from the key before or after it is started into the keyway; and the key may, for instance,'be placed in a heavy vise with the desired amount project-l ing beyond'one of these weakening nicks or notches and then by striking the projecting end laterally with a heavy hammer it 'can loe broken oit and the remaining end portion i ground or otherwise smoothed up before driving the key home.

i Fig. 5 shows another illustrative arrangement for making the key length adjustable and as there'shown, the self-fitting key may y `have a hardenedhead 32 comprising the cutting edges or portions andthe guiding aligning portions of the key, while the opposite or reardriving end S3 of the key is left in soft or annealed condition so that more or less of this end can be cut off by hack saws or otherwise removed before the key is driven into the keyway, and of course, if desired, a beveled portion'such as 34 may be formed to prevent undesirable spreading of the extreme driving' end of this key where the upsetting forces are usually large. Such keys may have any suitable arrangement of cutting edges and, as indicated, the hardened head 3201i the keymay be provided with the cutting edges 39 on its opposite lateral or driving faces, any suitable chip .recesses such. as 4-0 being ground or otherwise formed :id-

Qacent` these edv'es. In this case the u wer a l cutting edge 38 is shown as being formed with the bottomk of the keyway inthe shaft which is usually fairly straight on this-lower milled surface-thus prevcntingor minimizing subsequent twisting or bendingj off the key during itsfdriving whichis ofcourse un desirable. formed with a-somewhat reduced forward aligning guiding portion having. thezlateral faces 37 and the uppeiyfacefwhich may be formed with sharp cuttingI edges such as 35, if desired. y, y y

Fig. 6 shows'another illustrative self-litting key 24 which-may vhave anumber of cutting edges 27, 28- and 29 ononefor both of the driving faces 30, and-also if desired such cutting edges as may be formed on one of the other faces of the key at right angles to thesedriv-ing faces.y These-cutting edgesare of course progressively large r. so that each cutting edge removes part of the materiales the'key is driven forward, and this is of course advantageousy since rthecutting edges are less likely to vbebroken or. injured as the key is driven home. ln some cases it isdesirable to form the leading cuttingfedge with a substantially parallel guiding or aligning face or. member .26 adjacenttlie same, which somewhat promotesy the desired lateral positioning ofthe key as it.Y `driven into the rough keyway. @f course by` having different or oversized lself-fitting keys of this character worn orloosened key connections can be reiitted and tightened, and when initially connecting keyed partsthe very. cousiderable expense and time .usually required for-accurate fitting and finishing-is obviated. lt .seems desirable tomake such oversized self-fitting keys about five one-thousandths or ten one-thousandtlis of an inch larger in `each transverse direction where cutting action takes place thanr the standard size self fitting keys of this character, so that badly .fitted or worn keyways` can. be effectively taken careof'inthis way, and where a selffitting key has beenrepeatedlydriven out the parts may be tightlyfitted and'wedged apart by the useof such a special or. oversize l-rey. YVhere it is expectedthat.suchself-fit-- ting keys `are to be removed. especially` where, such removal takes place at relatively. frequent interifalsit is quite desirable to heavily oil fn'grease the keys, especially attheir forward portions, before driving them, effective lubrication .preventing the abrasionfor cutting action which otherwise. sometimes tends totake place Abetween the fiatk surfaces of the keyway and `thesideslof the keyA back of. its cutting edgeswhere these faces are so strongly pressed together without.y lubrication.I lfihenzproperly lubricated', however, a.

suit-able selfritting key may bedriven. out

The key may as- .indicated be a-nd'replaced a number of times with ordinary. care without undesirably loosening the connection.

Figs. 7 andi 8 show another illustrative forinof self-fitting key in which a wedging tapered'portion or face 42 is formed on one of the longitudinalfaces of the key, prefer.- ably onzits outerface and this tapered portion may have the .usual` degree of taper of an eighthof an inchA per footfor relatively short hardened keys of this character, so as to` lit in the'keyyway which may be cut with al siniilarktaper. The. key. may be formed with one or Vmore lateral cutting edges49 a1id,.ify desired, a reduced forward aligningr or guiding portion 44 may be formed so as to provide a. guiding` face or Vmember ahead of yeach of these cutting edges 49,. and formed with lateral and vtopcutting edges 45.-, 46,@ if desired. v Vith this arrangement wluneftliev wedging upper` surface 42 of the key isfcarriedidowntoyor adjacent the cuttingfedges 49 it is `naturally somewhat narrowen than these cutting edges 49 or the rearwardly extending lateral faces `of the key body 4l., For vthis reasonthe tapered face between its edges 43rproperly engages and cooperates with the.I tapering keyway originally. formed in-the shaft and cooperating partivhich promotes the accuracy of lit between. these parts. v

Figs. 9l and 1,0 show another illustrative form of key inwhich the cutting edges are formed with a. cutting angle ofy about 90o which'` cuts fairly well, although` not quite as easily in such materials, as a cutting angle of about 750 illustrated in connection. with thev other figures. This key. 51 may have the lateral cuttingedgesand the upper cutting edge 52 of such character and where av forward aligning guiding portion.

edges whichmay thus be located'at .the same.

longitudinal point on the key.- If desired, similarsquare or 90@ cuttingedges such as 56 may be formed on the forwardvaligning guiding portion of thekeyto take careof any projectionsl or irregular portionsof the ykey-way.v As indicatedin Fig, 9, the cut-ting headfoffthis keymay be. suitably hardened while the other. or rear driving end' ofthe key may be left.: in soft or annealed condition sothat more or less off this end caribe cut..off. by. hack saw-s or otherwise'removed beforey the key isl driven into a keyway as in-tliecase of"theFigrgxl 5-key. Fig.l 10 also illustrates the use of' slightly rounded or beveled corners or longitudinal edges 58 on these keys which are sonietin'ies desirable to prevent the workmen cutting themselves on the sharply ground edges which are naturally formed in finishing the keys and also to reduce the undersirable cutting action' on the metal which sometimes occurs with such sharp edges. These self-fitting keys have proved Very successful under service condit-ions and careful tests made with such keys as compared with the ordinary keys which vhave been hand fitted with unusual care show that the self-fitting key allows considerably less yield between the 4parts under similar loads or forces so that a much greater degree'of rigidity and strength of driving connection is thus `secured while` the long and expensive hand fitting of the usual keys is completely eliminated.

This invention has been described in connection with a number of illustrative eml'aodimentsa forms, proportions,y orders of steps, arrangements, sizes and materials, to the details of which disclosure the invention is not of course to be limited since what is claimed as new and what is desired to be secured by 'Letters Patent is set forth in the appended claims.

kl. The process of fitting driving keys in the rough keyways of shafts and cooperating parts, which comprises driving into such 'a keywvay a rectangular sectioned key and simultaneously sizing or fitting at least two rectangularly located inner surfaces of the keyway and tightly forcing and wedging into the sized keyway the adjacent body portion of the key. j

2. rlhe process ofr fitting driving keys in the keyways of shafts and cooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously sizing at least two rectangularly located inner surfaces of the keyway and tightly forcing into the sized keyway the body portion of the key.

3. The process of fitting drivii'ig keys' in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously sizing or fii'iishing at least several of the inner surfaces of the keyway by cutting portions :formed adjacent the forward'end of the key and forcing and wedgng into the sized keyway the :.zdjacent body portions of the key.

Il. The process of fitting driving keys in the i krough keyways of shafts and cooperating parts, which comprises driving'into sucha keyway a` rectangular sectioned key and s1- multaneously sizing or finishing at least one yof the inner surfaces of the keyway by a cutting portion formed adjacent the forward end of the key and forcing and wedging into the sized keyway the adjacent body portions of the key.

The process of fitting driving keys in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously sizing or fitting the keyway, forcing into the sized keyway the adjacent body portion of the key and also inremoving undesirable parts of the rear end of the key to adj ust its effective length. l

'6. The process of fitting driving keys in the rough keyways of shafts andcooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously sizing or fitting at least two rectangularly located inner surfaces of the keyway and tightly forcing into the sized mywayfthe bodyportion of the key and also in removing undesirable parts ofthe rear end of the rkey to adjust its effective length.

Y. T he process of fitting driving keys in the rough keyways of shafts and cooperating` parts, which comprises driving into such a keyway a rectangular sectioned key and simltaneously sizing or fitting at least two inner surfaces of the keyway and tightly forcing into the sized keyway the body'portion of the key and also in removing undesirable parts of the rearend of the key to adjust its length.

8. The process of fitting keys in the keyways of shafts and cooperatingpart's, which comprises driving into such a keyvvay a rectangular sectioned key and simultaneously sizing at least two rectangularly located inner surfaces of the keyway and tightly forcing into the finished keyway the body portion of the key.

The process of fitting driving keys in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously sizing or finishing at least several of the inner surfaces of the keyway by cutting portions formed adjacent the forward end of the key and forcing or wedging into the finished keyway the adjacent body portions of the key having at least as great width as such adjacent cutting portions.

10. The process of fitting driving keys in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a. rectangular,sectioned key and sinultaneously sizing or finishing at least several of the inner surfaces of the keyway and forcing into ther finished keyway the adjacent body portions of the key to tightly conneet the cooperating parts.

11. The process of fitting driving keys in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a rectangular sectioned key and simultaneously cutting and finishing` at least one of the driving faces of the keyway by a plurality of successively acting cutting edges formed on the forvvardypart ofthefkey and simultaneously keepmgthe front part 'ofthe key 'in alignment andtrghtly forcing or Wedging the body lofthe key into the f'mished keyvvay totigh'tly co'imect thecooperiinished keyivay totightly connect the cooperating parts.

1S. The process of fitting ykeys in the rough keyways of shafts and cooperating parts, which comprises driving into such a keyway a polygonal Asectioned key and simultaneously cutting and sizing at least `one of the faces of the key'way by a cutting edge formed on the forwardpart of the key and tightly forcing thebody of the key into the finished keyvvayito tightly connectthe cooperating parts.

14. The process'offitting driving keys vin the keyways of shafts and cooperatingparts', which comprises driving into such a keyway aJ rectangular sectioned key and simultaneously sizing the vkeyway and 'forcing or Wedging into the sized Akeywaythe body ,portions of the key to tightly connect'the cooperating parts.

15. The process of fitting driving'jkeys in the rough keyWays offshafts and cooperating parts Whichcomprises driving into such a keyWaya rectangular 'sectioned key having an oiled cutting head and simultaneously cuttingv and' sizing atleast one of the faces of the keyWay and-tightly forcing and wedging thebody of`the'key into the finished keyway to tightly connect the cooperatino parts and drivingthel key out of the keyway when they parts'are to be'. disconnected.

16. The process oflitting driving keysl in the rough keyways of shafts and cooperating parts Which comprises driving into such a keyWay a lubricated rectangular sectioned key and simultaneously cutting and sizing at least one of the faces of the key- Way and tightly forcing the body of the key into the nished keyway to connect the cooperating parts.

17. In self-fitting drivingkeys, a key having a hardened cutting head comprising on at least one of its tWo opposite driving faces and on its outer intermediate longitudinal face a front aligning guiding member and a. cooperating rearwardly located main cut-y ting edge projecting outward further than said guiding member to AWedge said key as itis driven longitudinally into the keyway.

18. In self-fitting keys, a key having a cutting head comprising a Wedging cutting` edge'to Wedge said key as it is d 1iven longitudinally intothe keyway 19; ln self-fitting drivingkeys, a key having a `hardened cutting hea d and arelatively soft driving end adaptedto be 'out on' 'to shorten the flength of the key,said cutting headcomprising a cutting edge on atleast one of itstWo opposite driving faces and on an intermediate longitudinal face.

, 20. ln self-litting dri y'ing keys, a key having a hardened cutting head and a'relatively soft drivingend adapted to be cut off to shorten the ylength of the key,vsaid cutting head comprisinga cutting edge.

21. In self-fitting driving'keys, a key havink' a hardened cutting head and a relatively soft driving end adapted to be cut offto shorten the length of the key, said cutting head con'iprising acutting edge onat least one of itstvo'opposite driving ifaces. n

' 22.1` ln self-iitting keys, a key having a cutting head comprising a hard cutting edge und a relatively soft driving end.

23. In self-fitting driving keys, a rectangula-r sectioned key having on each of its two opposite driving faces and on at least the outer intermediate longitudinal facea rcutting edge and a front guiding aligning member `projecting outward 'less than said cutting edge and a chip retainer recess between each of said cutting edges and thelcooperating guiding members.

24;. lin self-iittlng driving keys, a rectanguiar sectioned keyhaving on each of yits two opposite drivingfaces and on at least an intermediate longitudinal face a cutting edge and a frontfguiding aligningmember projecting outward less than said cutting idinal face a ,cutting odge` and a chip re-y tainer recess adjacent each of said cutting edges.l n

26. ln self-fitting driving keys, a key having on at least one of its tivo opposite driving faces and on an intermediate longitudinal face a cutting edge.

27. In self-fitting driving keys, a rectangular sectioned key having on its outer longitudinal face a cutting edge having a cutting angle of about 75o or more and an adj acent'chip recess and a cooperating cutting edge on at least one of the lateral driving faces of the key.

28. In self-fitting keys, a key having a fiat side and havingon an opposing longiy lateral Wedging action toward said fiat side of the key simultaneously With the cutting action of said cutting edge.

29. In self-fitting driving keys a rectan-y gular sectioned key having on a longitudinal face a cutting edge having such a large cutting angle as to produce a lateral Wedging action simultaneously with the cutting action of said cutting edge. n

30. In self-ttingdrivingkeys, a key having a plurality of cutting edges on each one of several of its adjacent faces and having a front guiding aligning member projecting outward less than said cutting edges and a chip retainer recess between said guiding member and said cutting edges.

31. In self-fitting keys, a rectangular sectioned key having a cutting edge on each one of several of its adjacent faces and having a forwardly extending front guiding member.

32. In self-fitting keys, a rectangular sectioned key having a cutting edge on each one of several of its adjacent faces.

33. In self-fitting driving keys, a rectangular sectioned key having on each one of several of its adjacent faces a cutting edge and an adjacent chip retainer recess.

34. In self-fitting driving keys, a rectangular sectioned key of hardened steel having on each of its opposite driving faces a plurality of cutting edges of progressively increasing Width to produce a fit as the key is driven or forced into a rough iinished key- Way.

35. In self-fitting driving keys, a key having on one of its faces a plurality of cutting edges at progressively increasing distances from the opposing face. v

36. In self-fitting driving keys, a vsubstantially rectangular sectioned key formed on several of its faces with a pluralityof successively acting hardened cutting edges and with a chip retainer recess between said cutting edges.

37. In selfditting driving keys, a sub-A stantially rectangular sectioned key formed.

on one of its faces' with a plurality of cutbetween said Acutting edges.

38. In self-fitting drivingv keys, a key formed with a plurality of successivelyv acting hardened cuttingedges and with a chip retainer recess between said cutting edges.

39. In self-fitting keys, a substantially rectangular sectioned key formed on its opposing driving faces Witli a hardened cutting edge to resize the keyway as the key is forced into the same.

40. In self-fitting driving keys, a subst-an tially rectangular sectioned key comprising a cutting edge formed on one of its faces to size the corresponding side of the keyivay the key is forced into the same.

Lil. In self-fitting ydriifv'ing keys, a key having on each of its two opposite driving faces a cutting` edge and a front guiding ,aligning member projecting outvv rd less than said cutting edge and a chip retainer recess between said guiding member and said cutting edge.

42. In selftting driving keys, a key having on one of its faces a cutting edge and a front guiding aligning member projecting outward less than said cutting edge and a chip retainer recess between said guiding member and said cutting edge.

43'. In self-htting driving keys, a key liar'- ing on one of its faces a cutting edge and a front guiding member in front of and projecting `outward less thanv said cutting edge. l y

4d. In self-fitting keys, a key having on one of its faces a cutting edge and a front guiding member.

45. In self-fitting keys, a rectangular sectioned key having on eachvone of several of its faces a cutting edge and a'forivardly extending front guiding member.

4G. In self-fitting keys, a rectangular sectioned key having on one of its faces a cutting edge and an adjacent chip retainer recess.

47. In self-fitting keys, a substantially rectangular sectioned key comprising a cutting edge formed on one of its facesvto produce a tight tit as the keyis forced into the keyvvay. y

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