'Dec.3,194é. ' ~ J, KAPLAN _ - 2,412,048 MEANS FOR GRINDING. SMALL-HOLED BUS'HINGS Filed Nov.‘ 24, 1945 , INQENTOR , Josey/2 [(61 BY5a’ _ ATTORNEY " ' 2,412,048 Patented Dec. 3, 1946 UNITED, STATESIPATENT OFFICE 2,412,048 MEANS FOR GRINDING SIHALL HOLED BUSHINGS Joseph Kaplan, Brooklyn, N. Y. . Application November 24, 1945, Serial No. 630,638 3 Claims. (01. 51-103) 1 2 small holed bushings or other parts where the Fig. 5 is an enlarged axial section through the ?tting and bushing, which are in mating position. Fig. 6 is a perspective view of the ?tting and ings making it di?icult if not impossible to han to be ground rotates, while it is being ground byv dle same in conventional machines. a grinding wheel. The diameter of the ‘wire should be preferably about one to several ten thousandths of an inch less in diameter than the bore in the bushing in order to get good results in This invention relates to new and useful im provements in a machine for the grinding of the corresponding holding part pictured in detail outside periphery is to be concentric or in similar relation with the holes. 5 apart from the remainder of the machine. The main principle of the present invention More speci?cally, the present invention pro consists in having a centrally aligned stretched poses the construction of a, machine for grinding wire held ?rmly in between two chucks. The wire small parts such as bushings having a center bore acts as a stationary axis over which the bushing of extremely small size, the small size of the bush The new invention has particular application to the art of grinding to size, extremely small bushings concentric with their holes. Using it, an extremely high degree of accuracy will be 15 the concentricity of the inside and outside diam eters of the bushing. readily and consistently obtained, even where it The machine, according to this invention, com is required to prepare very large numbers of small prises two parallel vertical standards l0 and H bushings in rapid succession on one and the same holding two stationary chucks l2 and 22 respec machine, utilizing but a minimum amount of time tively. The construction of the tail stock of a for aligning, precision grinding and ejecting the lathe will very well suit the purposes of chuck bushings. It will readily be seen that the new 22 in adjusting the distance between the two method and machine are extremely efficient in chucks as needed. In the present instance chuck operation, yet eminently simple in design, easy to 22 is shown as having a stem 13 sliding in a bore install, and relatively easy .to operate Without dif ?culty even by unskilled operators lacking pro PO .~v1 in the standard I I, a set screw 28 being employed for locking the chuck 22 in any adjusted posi longed periods of training and instruction hereto tion. . fore necessary for efficient operators in this art. A ?tting or auxiliary bushing l1, best shown in Many other advantages of the invention will Fig. 4, is provided. Its function, as will presently readily appear to those skilled in the art study 30 appear, is to drive the bushing 26 (Fig. 3) while ing the teachings of the instant speci?cation. it is being ground. The bushing l1 consists of a A further object is to provide a machine for piece of round stock of steel having a hole l9 grinding small bushings exteriorly concentric drilled through the center and having a tooth with their axial bores, said machine having a sta extending diametrically across one end. This tionary wire held taut between two vchucks, the tooth 20 is adapted to ?t loosely in a slot 21 formed wire forming a support for the bushing to be in one end of the bushing 26. Bushing .26 has ground. an axial bore 25. For further comprehension of the invention, An electric motor 3| drives a pulley l4 mount and of the objects and advantages thereof, ref~ ed on the standard In by means of a belt. A dog erence will be had to the appended claims in which the various novel features of the invention 40 2| is secured to the pulley and has a collar sur rounding the bushing l1 and secured thereto by a are more particularly set forth. set screw 18. The dog has two arms secured in In the accompanying drawing forming a mate holes in the pulley. Thus rotation of the pulley rial part of this disclosure effects rotation of the dog and consequently ro Fig. 1 is a front elevational view showing the tation of the auxiliary bushing, the auxiliary machine of the present invention with the bush bushing, when its tongue 20 is disposed in the slot ing to the ground in position for having the meth 21 of the bushing to be ground, rotating this bush od of the present invention performed thereon. ing. ! ~ Fig. 2 is a plan view taken from above and In order to prepare the bushing 26 for external showing the embodiment of the invention shown grinding, the bore 25 must ?rst be made and the in the preceding ?gure. slot 21 must be milled therein. After the external Fig. 3 is a perspective view of a bushing used surface is ground, the end having the slot 21 may and prepared in accordance with this invention. be ground to eliminate this slot. Fig. 4 is a perspective view in detail showing The machine further comprises'a wire “i which the keyed ?tting which holds and causes rotation is ?rst secured in the chuck I2. The auxiliary of the bushing of Fig. 3. 2,412,048 3 4 bushing I1 is then slid on the wire and into the collar of the dog where it is secured by the set screw l8, the arms of the dog being inserted in the holes in the pulley. Then the bushing 26 to be ground is slid on the wire, the tooth 20 and slot 2'! being adjacent each other and inter ?tting. The end of the Wire I6 is then gripped in the chuck 22 which is then adjusted longitudi nally to give the correct distance between the faces of the two chucks and the adjacent, faces 10 of the bushings. This distance is preferably only a few thousandths of an inch, but is shown larger in the drawing for clarity. That is to'say, the ‘bushings, When inter?tted, do not entirely ?ll the . wire or rod secured at its ends therein, an aux iliary bushing mounted on said wire or rod said bushing to be ground being adapted to be mount ed on said wire or rod next to said auxiliary bush ing, said auxiliary bushing having means for lock ing with said bushing for rotating the same when said auxiliary bushing is rotated, and means for rotating said auxiliary bushing. , 2. A machine for grinding a bushing or the like having a central bore and a diametral slot in its end comprising two spaced standards, a pulley mounted on one of said standards for rotation, a chuck-secured to said standard, an electric motor for driving said pulley, a chuck adjustably se space between the chucks but some clearance is 15 cured to said other standard, a wire or rod se permitted to allow the bushings to rotate unham-l pered. cured at its ends in said chucks, an auxiliary vbushing freely supported on said wire or rod, a dog .secured to said auxiliary bushing and to said A grinding wheel 29, mounted on a shaft .39, is shown fragmentally in Figs. 1 and 2. This pulley for rotating said auxiliary bushing, said wheel is rotated by another motor, in a well known 20 auxiliary bushing having a diametral tongue in one of its ends for inter?tting with said slot in manner, to grind the bushing 26. The wheel said bushing to be ground, said bushing to ‘be 29 will be mounted for longitudinal movement ground being adapted to be freely supported on along the bushing 28. As grinding wheels of this type are well known, no further description or said wire or rod, and rotatable grinding means for grinding the exterior surface of said bushing showing thereof is deemed necessary. to be ground. ' In order to grind the bush-ing 2B, the motor 3. A machine for grinding a bushing having 3| is started and thus the bushing 26 rotates. At the same time the grinding wheel 29 is ‘started. an axial bore and a diametrical slot in one end comprising two spaced standards, a chuck rigidly The wheel 29 isrmoved back and forth along the bushing 2-6 until the exterior surface of the bush secured to one of said standards, a chuck adjust: ing has been ground the desired amount. After .ably secured to the other of said standards, a pul the outside diameter of the bushing is ?nshed ley rotatably mounted on the ?rst of said stand ards, means for rotating'said pulley, a wire or to size, the chuck 22 ‘is opened and the bushing, 28 removed and a new one inserted on the wire rod secured at its ends in said chucks, a ?tting I'B, whereupon the operation is repeated. rotatably mounted on said wire or rod having a diametrical tongue on one end for inter?tting While I haveillustrated and described the pre with said slot when said bushing is mounted on, ferred embodiments of my invention, it is to be understood that I do not limit myself to the pre said wire or rod, a dog connecting said ?tting cise constructions herein disclosed and the right and pulleyv for rotation of said bushing, said dog is reserved to all changes and modi?cations com having two legs secured in holes in said pulley ing within the scope of ‘the invention as de?ned and a' collar surrounding said ?tting and provided in the appended claims. with a set screw for ?rmly locking said collar and ?tting and rotatable grinding means for grind Having thusrdescribed my invention, what I claim as new, and desire to secure by United ing the‘ exterior surface of said bushing to be States Letters Patent is: ground. ' 1. In a machine for grinding a bushing or the like having a central bore, two spaced chucks, a _ V JOSEPH KAPLAN. .