Патент USA US2131327код для вставки
Sept. 27,‘ 1938. v.‘ F. LIPIPARD 2,131,327 LIVE CENTER Filed larch 13, 1937 h " . ~ > 3d a’ 2 v H 11.8.17 t 5 9 ,6. - 8 1o 24 \ ,0 15,6- 20 23 - mg, "WWW/:52 -. ' 30 5mm? ~ ‘ 65¢‘31'9' 6' \Y) , .. 2:’ 12 I _ _ ~ ~ "m' d“ awe/whoa, I 26 164M]! LIPPARD 2P“ ‘ 28 - - ~ ' , ‘ ; ~ Patented Sept. 27, 1938 2,131,327 UNITED STATES ‘PATENT OFFICE _ ‘I ' ’ 2,131,327 12 Claims. The present invention relates toa live center for tail stocks in metal ‘working machines. _ The invention is applicable to ‘any type of machine in which a pieceof work is'supported 5 between centers, and is rotated by. driving means, during which rotation 'a metal working operation is performed upon the'piece of work; The invention comprises essentially ‘a ‘live cen ter assembly, in which the center that'supports 10 the work is adjustable transversely of the _as sembly in order 'to support the work “eccentrica'lly ‘a live center constructed in accordance with the presentinvention. - Figure ‘2 is a plan View, the piston being shown in ‘section. ' 1 _ ‘ Figure 3'is 'anelevation of the front face of the ~#5 center assembly. ' Figure 4 is asectional view on'the line 4--4 of ‘ Figure '2. Figure 5 is a sectional view of the center as sembly. “ - , V i ' Figure '6 is a sectional view on the line 6—6 of upon its axis of rotation. ' Figure 5. One object of the‘inventi'on is ‘to provide a live center assembly having means whereby the Describing the drawing more particularly, and referring ?rst to ‘Figures 5 and 6, the live center 15 center may be ‘adjusted to rotateeccentrically of the assembly. . _ ' Another object 'is'to provide micrometer ad justment means, whereby the ‘degree ‘of "eccen tricity may be controlled. '20 (c1. 82-33) ' assembly includes ars'upporting element 1 having-~15 ‘the form of ‘a, standard taper, but which may _be of any desired con?guration to fit the tail stock ‘of a machine. At its forward end the supporting member 1 ‘may carry ‘a ?ange 8 ex Still ‘another object is to provide means "for insuring the turning of the center ‘with ‘the ‘work tending annularly, and forming the rear walk/‘120 (of "a bearing enclosure 9. Extending forwardly in order to cause the r'otarymot'i'on ‘of the ~work ‘centrally of the ?ange 8 ‘is ‘a stud III that sup ports ‘one element ll of ‘a ball race I2, the ele to be eccentric.. . _ Still another objectfis to provide "supporting means for the end of the‘ work engaged by the center in a yielding manner to permit ec ment 11 being advantageously mounted on the stud I0 ‘b-y'a press ?t. ~25 Revolubly carried by the stud Ill and bear centric rotation. ing member H is a head l3 comprising an an , . nular cup-like member 14 having a frontwall The ?eld to which theinvention is particu larly directed, and in connection with which it ‘I5 ‘and circular side wall 16. Theside wall l6 "carries internally a ball race member I‘! advan-‘s30 30 was developed, is that of grinding pistons. In modern internal combustion engines, and vtageously press ?tted therein and cooperating especially automobile engines, 'it'is customary to with the member H and balls I 8 to revolvably use pistons that are not truly ‘cylindrical. The support the head l3 upon the stud ID. The side pistons that are used ‘are ‘what ‘are ‘termed in ‘wall l6 has edges formed ‘to cooperate with the edges of ‘the wall ‘8 to form a grease seal to ex-; 535 35 the industry as cam-ground pistons, which means that they are slightly oval in form, particularly "elude dirt ‘and to maintain a supply of lubricant within the enclosure '9. A grease port l9 ‘may be adjacent their tops, this being to v'all'o'w for un provided. ' equal expansion due to the'pini‘supporting struc -It will be ‘seen from the "structure so far dis ture carried within the pistons._ In manufacturing pistons it ‘is customary to closed that the head I3 is concentrically re- @40 40 form the pistons in ‘the ‘form of a true ‘cylinder, 'volv'a'ble’upon the stud ‘I0. In order'to provide and then by a grinding operation, bring the for ‘adjustable eccentric rotation, the following center structure ‘is provided. pistons to the requisite slightly oval "form. ‘Here 'The front wall l5 "of the‘ head I3 is provided tofore this grinding operation has been'performed with a transverse dovetailed mortise 20, the '45 45 by highly complicated and expensive grinding machines. By means of the ‘present invention “said ‘mortise passing through the center of this grinding operation may 'be performed by rotation of "the ‘head. \Advantageously the mor any ordinary grinding machine. In addition to tise may vbe formed in a projecting rib-like ex the above described use, the invention is ‘applica ”tension 2! formed integrally with the wall l5, 50 "and ‘having ‘at each side a shoulder 22. ble to turning, or any other ‘field o‘f'm'et‘al work 'Slidably mounted within the ‘mortise 20 and ing where it is desired to "form "an ‘eccentric ' shaped to closely engage the sides of the mortise object. is a carriage vmember :233 preferably substantially In the accompanying drawing: “equal in length "to the diameter of the front Wall Figure 1 is an elevation ‘showing "schemati *ca‘lly a piston supported ‘between an "adapter and 115. :Themember'2'3 carries at its central portion 55 2 2,131,327 a cone-shaped center 24 that projects forwardly of the front face 25 of the rib 2|, and that is de signed to engage and support the center of the piston or other work to be operated upon. An ad lusting screw 26 controls the position of the car riage 23 and therefore of the center 24. The screw 26 is threaded into a bore 21 in the wall I 5 of the head, the bore being positioned closely ad jacent the inner surface of the mortise 20. Pref 10 erably the threads of the bore 21 andof the screw 26 are of a micrometer type, so that longitudinal movement of the screw will bear a de?nite‘ rela the center 24 and the head stock 38 of a grind ing machine, the head stock being provided with, an adapter 39 equipped with a driver 40 in ac cordance with standard practice. The driver“ extends forwardly from the adapter and engages 5 one of the pin bosses 4| of the piston to rotate the piston. Assuming that it is desired to eccentrically grind the top portion of the piston, as shown in ‘FigureHZ, the screw 26 isturned to give the proper 10 degreevof eccentricity of rotation to the piston, as indicated by the‘ scale 29. With the grinding tion to its amount of rotation. The screw 26 has _ .instrumentality of the grinder set at the proper an enlarged head 21a that overlies and engages‘ 15 that the end upon ofrotation the carriage of the23. screw It will in a be direction apparent to , cause the head to travel toward the center of the assembly the enlarged head 21a. bearing upon the end of the carriage 23, will cause the car 20 riage to move in a direction of motion of the screw. Preferably the screw is provided with, a pointer, as at 28 in Figure 2, and the wall of the head is provided with a scale 29, so that a deter mined adjustment may be easily made. Upon 125 the opposite side of the head is mounted a, back ing screw 30 threaded into the wall] l5, and hav ing an enlargedhead 3| that contacts the oppo site end of the carriage 23. By means ,of this screw, the carriage may be secured in adjusted .30 position and by tightening the vscrew, the car riage will be tightened against the head 21a of the screw 26, insuring that the scale reading is accurate. A scale 29a may also be provided in the front face of the assembly. _ distance, the machine is started, and as the pis ton rotates eccentrically, the grinder will operate 15 upon a portion of its surface at each revolution. "'When the grinding operation has been completed uponone side of the piston, the piston is reversed in'its position with relation to the center so that the opposite side may be ground. The reversing 20 operation may be accomplished by holding the head I3 ‘against'rotation, and by hand turning “the. head, stock 38in adirection reverse to its normal. direction of rotation, or it may be ac _complishe_d..]oy holding’ the, piston and turning 25 l the head,,l.3>in a forward direction. In either" method thefsh'arp edges of the ?ngers will slide easily over.fthe top surface of the piston. The reverse motion may be imparted to the'head stock from any suitable part of the machine that isugo accessible to thehand of the operator. In order that the grinding may take place at theproperpoint on the surface of the piston, the center of the head of the screw 26 is lined up with the center of'the pin hole 42 of the piston, and.;,_35 upon reversal of the piston, as above described,‘‘" From the foregoing description, it will be ap parent that rotation of the head l3 upon the stud ID will cause the center 24 to revolve in a plane ‘the opposite pin holeis lined up with the screw tary manner around the center of rotation of the 26. The head of the screw 26 indicates the por assembly, assuming that the carriage has been tion, that during the rotation of the piston, is -40 moved to place the center in a position removed farthest ‘from the centerof rotation of the head._,40 vfrom the center of rotation of the assembly. ,It‘ . Where ,it- isv desired to grind oif a portion of a will also be apparent that the circular rotation ,-piston other than that adjacent the pinhole, the of the center will cause a piece of work held be portion to be operated upon may be easily selected tween the center and a driving center of a ma _ by lining. it up withthe screw 26. ' , Referring further to Figures 1 and 2 it is some-. 45 45 chine, to rotate in an eccentric manner. In order to insure that the desired eccentric , times necessary thata piston be cam-ground only rotation will occur, instead of concentric rota in its uppermost portion, while sometimes it is tion between centers that are not in line, it is _ necessary to, cam-grind the piston throughout its necessary to insure that the head I 3 rotates upon length. Where only the upper portion is intended the stud l0. Means are provided for insuring to be ‘ground, the, procedurev as above described, 50 rotation of the head l3 by the rotating work. This means is provided in the form of spring ?ngers 32 mounted upon the front face of the wall I5 at either side of the rib member 2|, and 55 abutting the shoulders 22 thereof. The spring ?ngers include end portions 33 that lie closely adjacent the surface, and which are held by screws 34 having heads that overlie these end portions. The ?ngers proper are bent outwardly 60 and extend angularly forwardly from the por is correct. Where, however, it is necessary to , cam-grind a piston throughout its length it be comes necessaryto rotate the complete piston, . as‘ distinguished from one end of the piston, ec Vcentrically. In Figure 1 the method of doing this, 55 - isvillustrated. A piece of shim stock or other ma ‘ terial=of proper thickness, as illustrated at 42 in , Figure 1 is inserted’ between the surface of the adapter 39 and the inner surface of the piston. - Where it is desired togrind off the same amount 60 tions 33 and in a direction, opposite to that in _ of the piston throughout its length and along one which the head rotates, and terminate in sharp cornered edges 35.-v Thesharp corners of the edges 35 engage the surface of the work, as shown in Figures 1 and 2, with sufficient security to in sure that the head l3 rotates upon the stud I0. Inasmuch as the rotation of the work is eccen side, the material 42 will be selected of the same width as the amount that the center 24 is moved off center. It will be readily realized that dif ferent degrees of taper in the ground area may 65 be provided by relating the thickness of the ma .terial 42 to the adjustment off-center of the tric, the distance between the face of the work, center 24._' 7 ; _ as the .top surface 36 of the piston 37, shown in By use of this center assembly, any sort of co Figures 1 and 2, and the front surface of the centric operation may be performed in a machine 70 head, constantly varies. The resilient nature of ,in which the work is supported between centers. the spring ?ngers 32 permits this variation. While it has been described as applied to a ma In Figures 1 and 2 is illustrated, somewhat chine for grindingpistons, it will be readily ap schematically, the method of use of the center parent that it _may be-applied to other metal assembly. A piston 31 is shown mounted between _ working machines in which the work is revolved._ 75 2,131,327 3 its use, an ordinary rotary metal working ma chine may be used for operations that heretofore mortise extending transversely across its front end and passing through the center of rotation, a carriage member slidably engaged in the mor tise, means for securing the carriage against movement in the mortise, a forwardly extending center mounted upon the carriage, and spring required the use of complicated and highly spe cialized machines. ?ngers mounted at either side of the mortise, the said ?ngers each extending angularly forward of The assembly provides for controlling the ec centricity given to the rotation of the work with the utmost precision. The assembly is simple and relatively inexpensive to construct, and by It is an essential feature of the invention that the adjustment of the center with respect to the center of rotation be located forwardly of the bearing assembly that permits turning of the head with respect to the stationary portion of the assembly, because an adjustment located rearwardly of the bearing assembly would result merely in two out-of-line centers, by means of which a tapered piece of work could be produced, but which would not cause eccentric rotation of the work. Similarly a dead center adjustable to a position out of line with the driving center will result in a tapered piece of work, rather than an eccentric one because the work rotates upon a the face in a direction opposite the direction of motion of the machine and forwardly of the front face of the head to a point to be engaged by work in the machine. 6. In a grinding machine, the combination with a driving center and a tail stock substan tially in line with the driving center, of a live center having a stationary stud engaged in the tail stock and substantially in line with the driv ing center, a head rotatably mounted on the stud, and a center movably mounted on the rotatable head and for transverse adjustment thereon. 20 7. In a machine for eccentrically grinding‘ pis tons, a revoluble support for one end of a piston, dead center and does not result in eccentric rota tion of the work. From the foregoing it is thought that the con struction, operation and many advantages of the herein described invention will be apparent to those skilled in the art without further descrip tion, and it will be understood that various a second revoluble support forlthe other end of ing means carried by the head for engaging work supported by the center for driving the head from the work. 3. In a live center assembly for machines, the said assembly including a stationary stud and a 50 head rotatably mounted thereon, and having a front face, the combination with a center mount ed on the front face of the head and adjustable transversely of the face, of spring means carried by the face and located out of the line of adjust 55 extending transversely of its front face, a center slidably mounted in the mortise, and screw threaded means carried by the revoluble head for adjusting the position of the center in the 45 the piston, and means carriedby the second rev oluble support for holding the end of the piston h in eccentric relation to the axis of rotation of the said second revoluble support. 8. In a machine for eccentrically grinding pis tons, including a head stock and a tail stock, the changes in the size, shape, proportion and minor combination with a driving support for one end 30 of a piston, of a live tail-center comprising a sta details of construction may be resorted to with out departing from the spirit or sacri?cing any tionary stud mounted in the tail stock, a head rotatably mounted on the stud and transversely of the advantages of the invention. adjustable means carried by the revoluble head What I claim, is: 1. In a live center assembly for machines, a i for supporting the other end of the piston. 9. In a live center comprising a stud for sta stationary stud for mounting in the tail stock of a machine, a head rotatably mounted on the tionary mounting in a machine, a head revolubly stud, and a center movably mounted on the front mounted upon the stud and having a front sur face of the head for adjustment transversely of face, and a center movably mounted on the front face of the head, and at one side of the center 40 the head. 2. In a live center assembly for machines, the line of the stud for eccentric rotation about the said assembly including a stationary stud and a axis of the stud. 10. In a live center comprising a stud for sta head rotatably mounted on the stud, a center tionary mounting in a machine, a head revolubly mounted on the front face of the head for move mounted upon the stud, and having a mortise 45 ment transversely of the head, and work-engag ment of the center, the said spring means ex tending from the face of the head to a point where they are engageable with work engaged with the center. 60 4. In a live center assembly for machines, the said assembly including a stationary stud and a head rotatably mounted thereon and having a front face, the combination with a center mount ed on the front face of the head and adjustable 65 transversely of the face, of spring ?ngers secured to the face at either side of the center, and ex tending angularly outward. from the face of the head and in a direction opposite to the direction of rotation of the machine. 5. A live center assembly for machines com 70 prising a stationary stud, a head rotatably mounted on the stud and having a dovetailed mortise, the said screw threaded means being ac 50 cessible at the side of the head for operation while the center is mounted in a machine. 11. The process of eccentrically grinding pis tons that comprises supporting a piston between centers, rotating one center and the end of the 55 piston supported thereby eccentrically, and dur ing said rotation grinding off a portion of the piston along a line parallel to the center of rota tion of the piston. 12. The process‘of eccentrically grinding pis 60 tons that comprises rotating a piston eccentri cally between centers, during such rotation grind ing off a portion of one side of the piston along a line parallel to its center of rotation, reversing the eccentricity of rotation of the piston between 65 the centers by rotating the piston with respect to the centers, and grinding off a second portion of the piston on the opposite side to that first ground along a line parallel to the center of rota tion of the piston and during its rotation. 70 VAN F. LIPPARD.