US2327297A - Drift - Google Patents

Description

' Aug. 17, 1943. F. J. WOODRUFF 2,)

DRIFT Filed April 7, 1942 'ATTORN s.

Patented Aug. 17, 1943 T "OFFICE DRIFT Francis J. Woodrufi', Detroit, Mich, assig'nor of oneilhalf to John Thomas Gilmer, Detroit, Mic w Application April 7, 1942, Sean No. 438,017

2 Claims. 7 (01.254-404) This invention relates to drifts of the type used by mechanics, commonly known as key drifts, and the principal object is theprovision of a drift of new and novel character which eliminates certain disadvantages of conventional types of such drifts.

Objects of the invention include the provision of a drift which when employed for removing a gear, pulley or the like from a shaft it Will not cause the gear or pulley to cock on the shaft and thereby resist removal therefrom; theprovision of a drift of the character described by the use of which the pressure applied by the drift to the piece to be removed thereby may be applied in such a mnner as to reduce the bending force on the piece as compared to a conventional drift; the provision of a drift of the character described so constructed as to eliminate the tendency of conventionaltypes of drifts to slip out between the parts being separated thereby; and the provision of a drift of the character described that is double wedge shaped in conformation whereby to enable certain advantages to be obtained thereby and certain disadvantages of conventional types of drifts to be dispensed with.

The above being among the objects of the present invention the same consists in certain novel features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which illustrates suitable embodiments of the present invention and in which like numerals refer to like parts throughout the several different views,

Fig. 1 is a perspective view illustrating a pair of pulleys mounted on a shaft and illustrating the use of a drift constructed in accordance with the present invention to remove one of the pulleys from the shaft and a drift constructed in accordance with the present invention to remove a key securing the other of the pulleys to the shaft;

Fig. 2 is an enlarged perspective view of a lefthand drift constructed in accordance with the present invention;

Fig. 3 is a transverse sectional View taken on the line 3-3 of Fig. 2;

Fig. 4 isa perspective view of a righthand drift 7 constructed in accordance with the present invention Fig. 5 is a transverse sectional view taken on the line 5-5 of Fig. 4;". a

Fig. 6 is a perspective view of a combined right and left hand drift constructed in accordance with the present invention; and,

Fig. 7 is a transverse sectional view taken on the line 7-1 of Fig. 6.

Drifts of the type herein under discussion are forms of wedges usually having a constant width and varying in thickness. They are conventionally formed from steel and are usually of hardened character. They are conventionally employed between a pair of machine parts which it is desired to separate from one another and in employing the same the smallend of the drift is inserted between the parts and pressure is applied to the thick end of the drift, usually by a hammer or equivalent means, thus to force the drift between the parts and cause them to be wedged apart. Such drifts are commonly called key drifts for the reason that one of their major uses is to remove the driving keys between a shaft and some part fixed to it for rotation, the keys in such case usually being provided with a head projecting outwardly beyond the surface of the shaft between which and the 'part mounted on the shaft the drift may be inserted .and. driven. Such driftsalso find wide use in removing pulleys, gears; or like objects from shafts, this being conventionally accomplished by inserting and driving the drift between the hub of the pulley, gear, or the like and some parts fixed to the shaft and providing a face lying in a plane perpendicular to the axis-thereof. p

In the past it has been conventional practice to form such drifts of rectangular cross-sectional configuration. As a result, if the parts between which the drift is forced are worn or battered the wear or battering has usually occurred radially outwardly from the surface of the shaft on which they are mounted with the result that there is a tendency for the drift to be displaced radially outwardly between the parts upon pressure being applied thereto before a sufficient amount of pressure can be exerted longitudinally through the drift to separate the parts axially of-the shaft. Where this condition exists the removal of a part from a shaft often becomes an exasperating job in view of the 'difficulty inmaintaining the drift in that position to which it is requrecl to be maintained'in order to effect its purpose. If the parts between which the drift is positioned are provided with surfaces which are not worn or battered and lie in planes perpendicular to the axis of the shaft; then there is a tendency for the driftto exert its pressure between the radially outward parts of such surfaces and particularlywhere the part to be removed is a gear or pulley having a relatively limited axial length or dimension, the pressure of the drift has a tendency to cock the gear or pulley on the shaft and to cause its axially outer edges to dig into the surface of the shaft and resist movement thereof on the shaft under the force of the drift.

The disadvantages above described in connection with drifts of conventional construction is obviated in accordance with the present invention by so forming such drifts not only are they wedge-shaped longitudinally as in conventional drifts but additionally they are more wedge-shaped in transverse section. In other words they are similar to conventional drifts in being longitudinally tapered to wedge-like form; but additionally the transverse dimensions of one of the side faces of the wedge: are uniformly less over the length thereof as compared to the corresponding dimensions of the other side face of the. wedge, thusforming the drifts. with one edge formed by the juncture of two surfaces dis.- posed at less than 9 'degrees with respect to each other.

With a drift formed in accordance with. the present invention and as above described,v that edge of the drift formed by the surfaces disposed at lessv than 99 degrees with respect to each other is. applied to. the shaft at the junction. between the shaft and the part to be removed. therefrom and then pressure is applied, to the drift in the usual way.. Because of the angularity of the two sides referred to no pressure: is exertediby therdrift upon the part tov be removed from the shaft radial l-y outwardly ofv its point of contact with the: shaft and consequently no tendency to cock the part on the shaft occurs toresist removal of the'part. Furthermore, because. the line of contact: between the parts to be: removed from the shaft and the drift is limited to a line intersecting the surface of' the shaft and perpendicular to the line of contact between the drift and; theshaft and: the drift is. free of contact with the'part: to beremoved: radi'aliy outwardly of such line of contact between the drift. and. the shaft, there is. no tendency'of' the drift to slip radially: out:- wardly with respect to the part to be removed from the shaft. Thus" two. of: the major disadvantagesof conventional drifts are obviated:

The same general remarks apply where: the drift is employed to-remove a key from between a shaft and a partmounted thereon as in such case the' sharpedge of the drift; that is, that'edg'e formed by the junction of the two surfaces 10- ca-ted at lessthan- 90- degrees with respectto each other, is placed againstthe head of the key-at its point of junction with thebcdy-of the hey; this reducing any cocking tendency between the drift and" the key to a minimum and elimihating the tendency of the drift" to slip radiallyoutwardly of the shaft with respect to the head oflthe key.

' From the above it will be observed that it is the preferredpractice in the. employment of a drift, constructediin accordance with the present" invention. to always place the sharp edge off the drift. against the part which is. to be removed from another. part. and asclcse to the area of junction. of, the parts as is practical under. the: circumstances. Actual practice-has demonstratedthat drifts constructed in. accordance .witl'rthe presentinvention are: much. more efficient, are longerlived and permit themto; accomplish .thein intended result in a quicker and easier manneror less than conventional drifts as heretofore constructed.

Drifts constructed in accordance with the present invention may be righthanded, lefthanded, or may be constructed to include a combination of both. They are designated either as righthanded or lefthanded depending upon which side I towards its longitudinal center line on one face thereof, thus providing two sharp edges in a single drift. Referring now to the accompanying drawing, in Fig.. 1,, in order to illustrate the application of the invention, a cylindrical shaft is indicated at. 1-0 and as havinga pulleyend thereof and a pulley M mounted adjacent the other end thereof. The pulley I12 is shown fixed for equalI rotation with respect to the; shaft l0; by meansofakey It received in the groove of key-way IS in the shaft {0 and ina complementary groove or key-way (not-shown)- inv the bore of the pulley l-2.. The outer end of the key 16- is provided with a. radially proj ecting, head 20. in accordance with conventional practice. Where a key such as: If is employed the pulley 1.2: will conventionally have a sliding fit on the shaft l9- and will ordinarily be locked" in position by means of. the key lBso that upon removal of the key t8. the pulley, IZma-y be removed from the shaft The pulley l4 may be assumed to have alight. press fit upon the shaft'l-fi and in such case. a. key such. as employed in connection with the pulley I2. is neither necessary nor desirable unless the, pulley is to besubjected to extremely heavy turning. forces.

order. to remove the key it from the shaft ii and pulley 5.2 a drift is ihsertedbetween the head' 25] of the key. L6 and thehub of the pulley I2 andthedrift is. driven as by means of a hammer between theseparts the key 15 thus being: forced. axially along the shaft frombetween the shaft and the pulley 12;. Where it. is desired to remove a pulley such as M from. the shaft m the shaftlwill' usually: be provided with a collar as Ed fixed to the shaft, at onev side ofthe pulley or be prOVl'd'ed with a radial shoulder corresponding with the end surface of the sleeve 25 and between which and the hub" of the" pulley M the small end of the di'iftmay be inserted as shown and driven-homeas by means of a hammen 22 to cause the pulley l4 to'bedisplaced axially along the shaft 02- If in the caseshcW-nin Fig; l the drift is aconventional rectangularly sectioned drift and the inner radially disposed face of the head 2-0 of; the key 5 5 isworn or battered it will be ap preciated'; slit in driving the drift between the head of the key and the pulley l2 there \v-illbe atendenoy for the-drift to slip": radially outwardlysbetween; thev part that it. isv intended to sepa'- rate, On the other hand, if the: surfaces referred to: are; square. then; there. willi he a! tendency for the dr t to bear against tlieradi'allyouter edge of-the-inner face of the head=29of the key [6 and to; force the axially outer'radiailyinner: edge: of the key 55 into the metal at the bottomrof the key-wayiii-thusto dlg' into;s-uch metal and to increase the resistance to its removaL.

Inthe: case ofthe; pulley M if the drift-eml-Z mounted on one contact with the surface of the shaft ed is a conventionally rectangular sectioned the cooperatingfaces between which the drift is received are not worn or battered so as to engender slipping out of the drift, then there will be a tendency of the drift to bear against the radially outer edge of the hub of the pulley it and to cause the pulley to cock on the shaft 59 so that its axially outer edge will tend to dig into the surface and resist removal.

The drift 38 indicated in Fig. 1 between the pulley id and the sleeve 24 is a lefthand drift constructed in accordance with the present invention as illustrated in greater detain in Figs. 2 and 3. Referring to these figures it will be appreciated that thedrift 3%! there shown is formed from a piece of metal, preferably steel and preferably hardened, is of an equal width throughout its length which is preferable but not necessary in the particular form shown, it tapers, in the particular form shown, uniformly in thickness from one end to the opposite end thereof, and in accordance with the present invention the thickness tapers in transverse section from one side thereof to the opposite side thereof so that the lefthand face thereof as viewed in Figs. 2 and 3 is uniformly of less thickness, or of less dimensions transversely -of its length, throughout its length than the thickness or corresponding dimensions of the righthand face thereof at a corresponding position in the 7 length of the drift. The bottom face 32 drift 3! is located in a plane perpendicular to both side faces 34 and 36 but the angularity between the side face 38 and the top face 33 as viewed in cross-section and as illustrated in Fig. 3 is less than 90 degrees so as to form a sharp edge do. This feature imparts a'trapezoidal section to the drift. Ihe angularity between the faces 36 and 38 insectional view may, of course, vary between greater or lesser limits, but if arranged between 75 and 80 satisfactory results of the will usually be obtained.

When employing the drift 30 for removing a pulley such as I 4 from the shaft such as ID as illustrated in Fig. l, the face 36 is positioned in H1 between the hub of the pulley l4 and the sleeve 24 with the shar edge 40 bearing against the hub of the pulley M, in the same manner as previously explained and for the same purposes. Because of the sharp edge 40 the pressure exerted on the pulley M tending to force it axially of the shaft It is exerted and a minimum radial distance from the axis of the shaft I andpulley M and consequently exerts a minimum tendency to wards cooking the pulley I 4 on the shaft l6. At the same time, because the sharp edge provides substantially the only line of contact betweenthe drift and the pulley' l4, it eliminates any tendency of the drift 30 to slip radially outwardly of the shaft HJ along the inner face of the hub of the pulley l4.

The drift 44 illustrated in Fig. 1 between the head 28 of the key I6 and the hub of the pulley i2 is a righthand drift such as illustrated in Figs. 4 and 5. The drift 44 is identical to the drift 38 in all respects except that in cross-sectional configuration it is tapered in an opposite direction. In other words the drift 44 includes a fiat bottom face 46 which lies in a plane perendicular to the planes of the side faces 48 and i! and out of parallelism with the top face 52. This drift 44 being a righthand drift the righthand face 58 is of less thickness than the lefthand face as, just the reverse from the corresponding faces as and 36 of the drift 3-), and so as to form a sharp edge 54 along the lei'thand edge of the drift as shown. In its application between the pulley i2 and head of the key l6 as in Fig. 1 its side face 68 is placed in contact with the radially outer face of the key 56 between the head 26 and the hub of the pulley l2 with the sharp edge 54 th reof engaging the axially inner face of the head 23 at its poi junction with the body of the key it as will be readily appreciated.

In Figs. 6 and 7 a combination drift embodying both features of the above described drifts 3G and 44 is illustrated and in effect it takes the same form as would occur if the drifts 36 and if were positioned in side-to-side relationship with the bottom surfaces 32 and thereof arranged in the same plane with the narrow edge surfaces 34 andi!) thereof in contact with each other and with their respective opposite ends in flush relationship with respect to eachother, except that in this case it would b formed in one piece. In other words, the drift indicated generally at 6B in Figs. 6 and 7 includes a plane bottom face 62, opposite side faces 64 and 66 arranged in parallel planes perpendicular to the plane of the face 62 and each having equal vertical dimensions uniformly increasin from one end of the drift towards the opposite end of the drift. The top face of the drift 6!] in this case is made up of two surfaces 68'and 10, each occupying one-half of the area of such upper face. The angularity between the side face SA-an-d the top surface 68 in cross-sectional configuration asillustrated in Fig. 7 is less than 90 degrees so as to form a sharp edge" and in a similar manner the angularity between the side face and the top surface portion 10 in cross-sectional configuration as illustrated in Fig. '7 is less than degrees so as to form the sharp edge'f. Thus the righthand side of the drift shown in Fig. 6 is equivalent to the lefthand drift 30 illustrated in Figs. 1 and 2 and the lefthand side thereof equivalent to-therighthand drift illustrated in Figs. 4 and 5. It will be readily appreciated that the drift 60 may be used in any case where either the drift 3!] or the drift may be employed.

Having thus described my invention, what I claim by Letters Patent is:

1. A key drift comprising an elongated metal member the side edges of which are substantially parallel to each other, said member increasing in thickness from one side edge thereof toward the other side edge thereof, the thicker of said side edges being flat, and one of the side faces being perpendicular to the plane of said thicker side edge, said member also increasing in thickness from one .end thereof toward the other end thereof.

2. A key drift comprising'an elongated metal member having fiat side edges arranged in substantially parallel planes and a flat side face arranged substantially perpendicular to the planes of said side edges, the remaining side face of said member being formed to present two flat surfaces intersecting one another medially of the longitudinal centerline of said remaining face and forming a re-entrant angle between them, said member increasing in thickness from one end thereof toward the other end thereof.

FRANCIS J. WOODRUFF.

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