US732738A - Keys and key-seats for shafting. - Google Patents

Description

PATENTED JULY 7, 190a.

, c. HAMMEN.

. KEYS AND KEY SEATS FOR SHAFTING. PPPPPPPPPPPPP LED DBO. 22222 1.

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v 50 the other-hand, if the lateral surfaces bind 1 first'the wedging efie'ct of the other surfaces, j

I ITED STATES TE T] OFFIC CHARLES M N, oF-cHIcAeo,ILLINois.

KEYS AND KEY-SEATS FOR SH'AFTING.

1 SPECIFICATION formingpart of Letters Patent No. 732,738, dated July '7, 1903.

Application filed December 2,1901. Serial No. 84,294. (No model.) Q

l 3e it known that 1, CHARLES HAMMEN, a citizen of the United States, and a resident of Chicago, in the county of (look and State 5 ofIllinois, have invented certain new and useful Improvements in Keys and Key-Seats for 'Shafting, of which the following is a specifi cation, reference being bad to the accompa- I Dying i gs, forming a part thereof.

k andkey-seats, as particularly described in the claims.

In the drawings, Figure 1 is a transverse section of a shaft, showing a hub of a wheel keyed thereto according to my invention.

Fig. 2 is a similar view of a slightly-modified construction. Fig. 3 is a section at the line 3 3 on Fig. 2. Fig-4 is a view similar to Fig. 1, showing a modification. Fig. 5 is a section at the line 5 5' on Fig. 4. Fig. 6 is a perspective view of thepreferred form of relief-key.

The customary construction of keys and key-seats,consisting of facing channels in the shaft and hub adapted to receive a key which is rectangular in cross section and has a slight taper in its dimension radial to the shaft, thechannels having corresponding taper, the key and channels, however, having their other sides parallel to the said radial diinension or with slight taper, is 0 on to certain well-understood objections.

If the surfaces tending to exert a wedging force radial with respect to the shaft come into binding contact and before like contact is obtained at the lateral surfaces, there is liable to be an initial possibility of play under thestress of reversed rotation, and the blow, however slight, which the key and seat receive in such movement tends to crush the metal and rapidly increases the play, which reversion of the direction of rotation.

the purpose of which is to force the shaft into such contac'twith the opposite sides of the,

bearing that the friction of such engagement shall constitute in'large part the means of holding the parts againstsli'pping, is defeated.

, The leading feature of my improvement;

consists in such form and location of the keyseats and keys t-hat'each key shall be required to produce-binding action only in one plane-that is, only one pair of its faces having this duty, the other two faces having no such duty, and v the key not requiring to be closely fitted in its seat in respect to the said other two faces, and being so fitted, iffat all,

only for the purpose of checking its expansion in that direction under the stress of the wedging pressure in the other direction.

In the drawings, A represents the shaft; B, the hub of a wheel secured thereto. primary form of my invention (shown in Fig. 1) I employ two keys 0 O, the seats of each" key in the shaft and hub,respectively, beingv angular and togetherforming a quadrilateral I are to be considered are formed one of them entirely in the shaft and the oppositeone entirely in the hub, so that the keyhaving a ta-' per in one dimension andwithout taper in the 1 other dimension being forced into this cavity tends to crowd apart the faces opposed in the direction of itstaperingd-imension, tending thus to rotate or roll the shaft slightly in its- Such action is not contemplated v and is prevented by the location of the other key at the opposite side, and preferably symbearing.

metrically disposed at the opposite side of a diametrical plane parallel to the tapering dimension of the key, so that by driving the two keys simultaneously the shaftis forced firmly into its seat in the hub, producing the most perfect frictional contact possible through-. out the entire half of'its circumference opposite the chord containing the two key-seats? As compared. with the usual structure of key lodged in a channel it will be seen that with .substantially equal reduction of the cross-area Patented July 7, 1903,

In the Of the cavities of the shaft by reasonof the cutting out of I the key-seats there is obtained double facility t for tightening, and at the same time the primary advantage of my invention is obtained namelygthat each keydoes d u tyin the direction of one dimension only and may therefore be driven home to the maximum degree of tightnessiu thatdimension not impeded by 'friction upontho other two seats, which need not even touch the walls of the recesses and,

; atmost, will be made only an easy fit, since no service exceptinclosing the key is required of these'opposite walls of the chamber.

In many situations in'which great security 15 of connection is required between shaft and wheel thereon -as, for example, in securing R PFOPGllGI WhEGI to its shaft-it is practically impossible to remove a wheel when once keyed rupture the hub.

sec'urely'under the old construction, and the only resort in case removal is necessary is to With my improved key i and seat it is" practicable to provide a comparatively easy means of withdrawing the f keys, so as to permit the removal of the wheel. I 5

In. Figs. 2 and 3 I have shown a form in which this can bedone. In this form instead of one ofthe-keys O, I provide a relief-key D, whose ever, being'preferablyvery much greaterthan would be desirable for a key tobe tightened intlie ordinary mannerthat is, instead of r I 35 having the taper aboutone-eighth of an inch amount, the key-seats being correspondingly tapered. This key hasahead D at the outer taper is in the opposite direction from that of the key 0, such key D being lodged in the angularkey-seat-s of the shaft and hub in the same manner as the key 0, the taper, howto. the foot, asis customary, the key D may have a taper of three or four times that end, which is stopped so that it cannot move longitudinally in the direction tending to slack it. Such key D being lodged in posi- 1 tion and the wheel passed onto the shaft beforethe key 0 is inserted or at least before it is tightened, so as to impede the application ofthe wheel to the shaft, the subsequent I tightening of said key 0 causes the relief-key upon the one key which is driven is more se- -vere it may be made of greater area than 5.5 when both keys are to be driven, as in the D to be bound tightly between its seats, all

the duty of tightening, however, devolving upon the key' 0, but with approximately the same ultimate eifect as if both keys were driven, although in this case since the duty original form. When it is desired to withdraw the keys and remove the wheel from the shaft, the head D of the key Dean be cut j off, and that key can then be driven inward,

which is feasible in view of the taper of this keybeing much greater than if it had been designed to be originally tightened by driving. The relief afforded by driving in this key will-of course relieve thekey O, which. In case of large shafts it may be found desirable to employ a i can then be withdrawn.

third key, the added key beingin all respects 'fore striking the bearing.

like the keys 0, but-for distinction denoted c on Fig. 2. This additional key will be preferably located about opposite thekey C and will be seatedso as to crowd tangentially in the same circumferentialdirection as the key ing the transmission of the pressure perfectly from the key Oarouud tokey D. When the wheel to be thus keyed onto the shaft is located near the hearing, so that thekey D can be driven only a short distance, it will be necessary to cut it away in pieces as it is driven through, and to facilitate this such key may be made, as shown'in Fig. 3, cut partly in two distance which the key can be driven in befirst driven in this distance will be cut off at the first slit and the piece cut off, and so on until the necessary relief is obtained.

It is practicable to combine a relief-key,

such as the key -D, with two opposed keys,

both of which are to be drivenasinthe first 'too' construction described. Such combination is illustrated inFigs. 4t and 5 and consistsin The key being I the employmentin connection with one of the V.

keys 0 of a false-key seat or relief-key E,

which has the form of the relief-key Dthat is, tapering in the opposite direction from the keys G and lodged in the seat oras alining of. the seat of one of the keys 0, the taper of' the cavity remaining for the key when such lining is in place being in the oppositedirection from the taper of the lining-that is, in the same direction as for the keys 0 O and at the same pitch. The relief-key or false-key seat E will be operated in the 'same manner as therelief-key D, that is its head E being cut off, and it may be driven; and it may be driven through to relieve the keys 0 G. In practice, probably, the key 0, which is lodged a in the relief-key or false-key seat IE, will bedriven in with said faIse-keyseat or-relief-i key, the net taper of theltwo parts combined being sufficiently great to permit such action. "1]

In this specification'and claims .I use the phrase the plane of taper to indicate the plane in which the dimension of the key bee. i I

in g m'easured'shows such dimension diminishing steadily from'one end tothe other'and the corresponding phrase taperingin' a transverse dimension to indicate the diminu- I tion of the transverse dimension as measured in'the plane division by. the description immediately following the said phrase.

In fl ing the'key-seatsin the shaftffi facing toward one sidev or the other of t p A v: sha'ft in the specification and claims Ij t J 9. by slits (1 cl at intervals not greater than the to-be understood asindicating the seat inthe shaft on which the key operates with binding or wedging effect and todistinguish that seat from the near lateral wall of the key-cham- 5 her .which may be formedby the other side of the angular out which is made in the shaft to produce the key-seat, since the key does not bind against said lateral wall or operate upon it in any manner with'tightening effect. I claim- 1. A shaft and hub having each two recesses for key-seats, which, when registered respectivel y, form rectangular key-chambers, taper ing in a transverse dimension which is approximately tangential to the circumference of the shaft; correspondingly-tapered keys in I said chambers, the shaft having its two key-- seats on which the tapering, keys act wedgewise, located facing toward the same side of fichambers being in opposite directions, and correspondingly-tapered keys in said cham- 30,, cesses for key-seats, forming, when registered bers respectively.

. 3. A shaft and hub having eacha pair of refacing each other, rectangular key-chambers tapering in a transverse dimension which is I approximatelytangential to the circumference of the shaft, and having their respective 'key-seats in the shaft facing toward opposite sides of the latter, said shaft and hub having I a third pair of recesses similarly registering to form a key-chamber, such third key-chamher being tapering in one dimension approximately tangential to'the circumference of I. thejshaft, itssaid taper being in the opposite.

direction from that of the other two key-chambers. v

4. .A shaft and hub having each two recesses for key-seats, which, when registered respectively, form rectangular key-chambers which taper in opposite directions, each in a dimension approximately tangential to the circumference of the shaft, their; respective key-seats in the shaft facing toward --the same side of the shaft; corrcspondingly-tapering keys fitting in said chambers respectively, one of the keys having transverse slits at intervals in its length, extending in from the face'which is seated on the shaft. I

5; A shaft and hub having each two recesses for key-seats, which, whgm registered respec-' tively, form rectangular key-chambers taper-'- ing ina dimension which is, approximately tangential to the circumference of'the shaft; tapering keys fitting said seats respectively,

one of said keys having a head at its smaller end to stop it against longitudinal withdrawal, such head being exposed so that it can i be cut off to permit the key to be forced out;

' 6. A shaft and hub,each having two recesses forkey-seats, which, when registered respec: tively, form rectangular key-chambers tapering'in a transverse direction, which is approximately tangential to the circumference of the shaft; tapering keys in said seats re- 7 spectively, one of said keys having at itssmaller end'a transversely-projecting head,

the shaft having a recess beyond the face of the hub to receive said key-head.

In. testimony whereof I have hereunto set" my hand, in the presenceof two witnesses, at Chicago, Illinois, this 21st day of Novem-;

her, A. D. 1901. v v q I -GHASLIIAMMEN. In presence of-- v l 1 OHAs. S. BURTON,

HAROLDWARNER.

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