US2653495A - Machine for knurling pistons - Google Patents

Description

Sept. 29, 1953 H. P. PHILLIPS MACHINE FOR KNURLING PISTONS 3 Sheets-Sheet 1 Original Filed Jan. 19. 1949 INVENJ'OIg. Ham/0 72 ,P/uM w BY i" ATTRNEfi Sept. '29, 1953 H. P. PHILLIPS MACHINE FOR KNURLING PISTONS 3 Sheets-Sheet 2 Original Filed Jan. 19. 1949 INVENTOR. flaw/d P Pfi/Z/f a ATTORNEY Sept. 29, 1953 H. P. PHILLIPS 7 2,

MACHINE FOR KNURLING PISTONS Original Filed Jan. 19, 1949 3 Sheets-Sheet 3 INVENTOR. Ham/0 F Pfif/7D0 @wm X A T'TORNEK Patented Sept. 29, 1953 MACHINE FOR KNURLING PISTONS Harold P. Phillips, Hastings, Mich., assignor to Hastings Manufacturing Company, Hastings,

Mich.

Substituted for abandoned application Serial No.

71,617, January 19, 1949.

This application June 7,1950, Serial N0. 166,700

15 Claims. 1

This invention relates to improvements in a machine for knurling pistons.

This application is a substitute for my abandoned application for Letters Patent filed Jan- 'uary 19, 1949, Serial No. 71,617.

The principal objects of this invention are:

First, to provide a machine for increasing the effective diameter of internal combustion engine pistons by knurling the side walls of the piston which machine is operative on all types of pistons without "danger of injury to the piston regardless of its wall thickness.

Second, to provide a machine for knurling pistons which employs a rapidly repeated application of a knurling tool to the pistonunder relatively light pressure.

Third, to provide a machine for knurling pistons which will rapidly oscillate a portion of the surface of a piston across a knurling tool held against the piston by relatively light adjustable pressure.

Fourth, to provide a piston knurling machine which is readily adjustable to accommodate pistons of varying sizes.

Fifth, to provide a piston knurling machine which is extremely simple and rapid in operation and which. will knurl both sides of a piston without removing the piston from the machine.

Sixth,"to provide a piston knurling machine in which the depth of the knurled portion on the piston can be easily and accurately controlled.

Seventh, to provide a piston knurling machine which is operative upon all forms of pistons regardless "of their interior construction and side wall thickness.

Eighth, to provide piston knurling machine that Will simultaneously knurl two parallel portions of a piston wall regardless of uneven wear or tapered condition of the piston Wall.

Other objects and advantages relating to detailsof the machine will be apparent from a consideration of the following description and claims. The drawings, of which there are three sheets, illustrate a preferred form of the knurling machine and various steps in the method of knurling pistonsas "well as two forms of knurling heads or tools for use with the machine.

Fig. 1 is a perspective view of the machine with an automotive piston in place thereon and partially knurled.

Fig. 2 is a horizontal cross sectional view through the machine and piston taken along the plane of the broken line 2-'-2 in Fig. '3.

Fig. 3 is a fragmentary elevational view par- 2 tially broken away in vertical cross section along the plane of the broken line 3-3 in Fig. :2. 4

Fig. 4 is a fragmentary cross sectional view illustrating the connection between the crank wheel and pitman arm and taken along the plane of the line 44 in Fig. 2.

Fig. 5 is a fragmentary plan view similar to Fig. 2 but showing a, multiple knurl knurling head in position on the machine.

Fig. '6 is a perspective view of the multiple knurling head.

Fig. 7 is a fragmentary cross sectional view along the line 'l 1 in Fig. 5.

It has previously been proposed to alter the efiective diameter of the pistons of internal combustion engines by knurling the side walls of the pistons. The knurling operationis performed in closely spaced lines along the side of 'the piston usually at from the wrist pin holes in the piston. The knurling operationcauses a displacement of the metal of the piston and raises a slight ridge along the sides of the knurled portions so that the effective diameter of the piston is increased at these raised portions. This practice is recognized as desirable to reduce the clearance between the piston and the cylinder in which it is to operate and either new or used pistons can be sized by knurling.

The previously known method of knurling the pistons consists of supporting the inner surface of the piston side wall or skirt against an anvil while pressing a knurling tool against the outside of the piston in opposition to the anvil under relatively high pressure. The knurling tool is passed over the selected portion of the skirt a relatively few number of times and the ribs of the knurling tool are relatively dull or round ed. This method of knurling has several disadvantages in that the high pressures utilized are liable to crush or distort thin walled pistons and because the use of the interior anvil prevents the method from being practiced on pistons having internal ribs or reinforcing bosses where the knurling operation is to be performed.

The present improved method of knurling pistons is practiced by rapidly oscillating the piston about a fixed axis for a short period of time and at the same time applying a relatively sharp knurling wheel to a selected portion of the outside of the piston with gradually increasing pressure but relatively light. The maximum pressure with which the knurling Wheel is pressed against the piston is substantially lower than the minimum pressure used in the whole method of knurling described above and the knurling wheel used in the present invention is preferably maintained in relatively sharp condition. A highly satisfactory knurl is produced when the piston is oscillated at between one hundred and forty (149) and live hundred (500) oscillations per minute. Of course pistons of different materials will require different treatments.

This new method is advantageous in that no backing is required on the inside of the piston so that the method can be practiced on all types of pistons regardless of their interior construction. The new method is further advantageous in that the relatively light pressures applied to the knurling wheel are insumcient to distort or damage the side walls of the lightest type of piston commonly in use at the present time. The method of sizing pistons is specifically described and claimed in my copending application, Serial No. 117,207, filed September 13, 1949.

The machine illustrated for carrying out the method consists of a base I which can be secured to any suitable bench or platform and which is provided with a principal cylindrical upright 2 and an auxiliary rod-like upright 3. Positioned between the uprights 2 and 3 is a vertically disposed headstock 4 which rotatably supports the work chuck 5. The upper end of the headstock is braced relative to the uprights by the cross member 6 having sleeve-like bosses i passing and secured to the uprights 2 and 3. The chuck is provided with radially adjustable jaws ii for clamping various sized pistons to the chuck as indicated at 9. The chuck 5 is secured to the double crank arm It provided with diametrically opposed wrist pins H.

The chuck 5 and crank arm 10 are arranged to be oscillated by the electric motor l2 carried by a suitable bracket l3 on the principal upright 2. The motor is connected through suitable reduction gearing, indicated at 14 in Fig. 2 to the crank wheel l5. The crank wheel 15 is radially slotted, as at Hi, to receive the radially adjustable crank pin ll. The crank pin i1 is arranged to receive the driving end of the pitman arm [8 while the driven end of the pitman arm is engaged with one or the other of the wrist pins II.

In order to make the pitman arm [8 easily engageable with either of the wrist pins I l, the pitman arm is provided with a flexible connection to the crank pin I? as is most clearly illustrated in Fig. 4. The driving end of the pitman arm defines an aperture I9 substantially larger than the crank pin ll within which the flexible rubber grommet 28 is positioned. The metallic sleeve it having an annular flange 22 is positioned between the crank pin and the grommet 2a to prevent wear between the crank pin and the grommet and the grommet is compressed to the desired degree by the nut 23 on the crank pin. It will thus be seen that the pit man arm can be tilted substantially relative to the crank pin so that the driven end can be lifted easily from the wrist pin ll. Preferably a similar grommet and liner 2% is provided at the driven end of the pitman arm for engaging the wrist pins I l.

From the foregoing description it should be apparent that the chuck 5 and piston 5 can be rapidly oscillated through an angle determined by the radial adjustment of the crank pin ll. After a pre-determined period of oscillation from one side of the crank arm it the pitman rod is easily lifted upwardly to permit the chuck and piston to be turned 180 to engage the opposite wrist pin with the pitman arm. A piston can then be oscillated a similar period of time with its opposite face presented to the knurling tool.

The knurling wheel for operating on the surface of the piston is indicated at 25 and is rotatably mounted on the end of a tool holder 26. The tool holder is adjustably clamped to the arm 21 so that the wheel 25 can be advanced to engage small diameter pistons or retracted for large diameter pistons. The arm 2? is provided with a sleeve 28 rotatably and slidably mounted on the principal upright 2. The upper end of the upright 2 is provided with a pulley 29 and a cable 30 is trained over the pulley between the arm 2: and a suitable counterweight, not shown, to facilitate vertical adjustment of the arm and knurling wheel. The arm 2'! can be clamped in its vertically adjusted position by means of a brake on the pulley 23 operated by the handle 3| and by means of a set screw through the sleeve 28 adjusted by the handle 32.

The free end of the arm 2! is provided with a horizontally extending cylindrical boss 33 which defines a bore receiving the threaded outer end of an adjusting screw as. The inner end of the screw 3 is provided with a sleeve 35 slidable on the auxiliary upright 3. A knurling adjusting nut 36 is threaded on the end of the screw 3 and bears against the outside of the boss 33. A coil spring 31 positioned between the inside of the boss and a shoulder on the screw 34 constantly urges the boss and the arm 27 outwardly from the chuck and against the nut 35. Preferably the nut 36 is provided with regularly graduated indicia 38 cooperative with a fixed pointer 39 on the boss 33 so that the movement of the arm 21 and knurling wheel 25 toward the piston can be predetermined and measured.

In order to assist the jaws 8 in holding the piston on the chuck and to assure that the piston is centered relative to the chuck there is provided a center cone 4% engageable with the upwardly disposed open end of the piston ii. The cone it is rotatably and releasably secured to the lower end of a sleeve 4| by means of the spring pressed ball 42 engaging a groove 43 in the sleeve. The sleeve 43 is press fitted or otherwise suitably secured to the lower end of a screw quill 44. The upper end of the screw quill 44 extends upwardly through a top cross member 45 secured to the upper ends. of the uprights 2 and 3 and is provided with a hand wheel 66. The screw quill 44 has threaded en" gagement with the cross member 55 for vertically adjusting the screw and the cone it upon rotary adjustment of the wheel 46. Preferably a split clamping block 47 is provided on the cross member 45 for clamping the screw 44 in any of its adjusted positions.

In order to stabilize and accurately locate the lower end of the screw 44 the screw is passed through a traveling bar 48 and axially secured thereto by the plate 49. The bar 48 is provided with a pair of rollers 50 at each end, the rollers being set at an angle to engage the sides of the uprights 2 and 3. The traveling bar 48 thus locates the position of the cone 4!] between the uprights. Vertical adjustment of the cone permits the machine to accommodate pistons of different lengths and vertical adjustment of the arm 2! permits the knurling wheel to be applied to any axial position along the piston as indicated at 5|. Cone members 40 can be provided in diiferent sizes to engage a wide range of pisaeeaccs piston against collapse under the pressure of t-he .knurling wheel.

In operating the machine to vre-size a piston the piston iscentered and clamped on the .chuck and the cone member lowered into engagement with the open end of the piston. .The arm 21 and knurling wheel 2.5 are thus vertically adjusted to the selectedheight on the pistons .and the 'knurling wheel moved into snug engagement with the piston and clamped in place. The chuck and piston are then oscillated fora short period of perhaps ;a minute while the operator gradually increases the pressure of the knurling wheel against the piston .by turning the wheel 36. ,After one knurl is "completed the piston and chuck are reversed as previously described and a knurl applied to the opposite side of the piston. The operation is repeated to provide as many vertically spaced knurls along the piston as is desired.

Fig. 5 illustrates a .modified form of tool holder 26A operatively secured to the arm 2'! in the same manner as the tool holder 26 in Fig. 1. The knurling tools on the tool holder 26A are movable into operative'position against the sides of the piston 9 mounted on the chuck 5 in the same manner as in Fig. 1.

The tool holder 26A consists of a bar-like member having a bifurcated forward end form- .ing the tool recess "52. The sides of the bifurcation are apertured to form bearings for the pin 53. The top of the pin is provided with a shouldered head 54 resting on the tool holder and the lower endof'the pin is grooved to receive the snap ring 55 to retain the pin in place.

Within the tool recess .52, the pin 53 is provided with .an upper bearing portion 56 concentric with the axis of the pin. The upper bearing portion 56 serves to rotatably support an upper knurling wheel 51. v.Below the upper bearing 56 the pin 53 is provided with a lower bearing portion 58 whichis eccentric with respect to the axis of the pin and the upper bearing portion 56. The eccentric bearing 58 rotatably supports a lower knurling wheel 59. The two knurling wheels are spaced by a washer 60.

The head 54 of the pin is transverselynotched as at 61 to receive an adjusting lever v62 retained on the pin 53 so that the eccentric bearing 58 will move the lower knurling wheel 59 laterally with respect to the upper .knurling wheel whose axis of rotation remains fixed. Thus the lower .knurling wheel maybe made to project slightly beyond the plane of the working face of the upper knurling wheel or may be retracted behind the working plane of the upper wheel. This arrangement of the two knurling wheels is desirable because it will be found that some pistons have been worn into tapered shape .sothat if the two knurling wheels are vertically aligned only one would contact the surface of the piston held in the chuck 5. .By proper adjustment of "the lever 62 both knurling wheels can be made to simultaneously contact the surface of any piston to produce two parallel knurled areas on the piston. The tool holder shown .in Figs. 5 to 7 will thus operate approximately twice as fast as the tool holder having the single knurling wheel.

The outer end of the tool holder 26 is provided with a sector bar -64 having the locatingnotches 65 formed in its upper edges. The notches 65 serve to engage the outer :end of the lever 82 and hold it in any of its angularly adjusted :po- :sitions so that after the operator has once ad- "justed the relative positions of the two knurling wheels 51 and 59, he is then free to operate the pressure adjusting nut 35 and the rest of the machine. Should it be found necessary to apply a single knurled area to a piston with the tool holder :having the double .knurling wheels, the lower 'knurling wheel can bereadily adjusted to the working place of the upper wheel so that only one or the :other of the wheels is operative.

It should be noted that only one chucking operation is required for each piston and that no hacking element is required on the inside wall of the piston. The machine can be operated rapidly and accurately Without danger of injuring the piston.

I have thus described a highly practical machine for performing a sizing operation. I have not attempted to illustrate all possible forms or variations of the machine as it is believed that the foregoing description will permit those skilled in the art to reproduce and operate the machine and practice the method without further disclosure.

Having thus described my invention, what I claim as'new and desire to secure by Letters Patent is:

'1. A machine for knurling pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned vertically between said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having diametrically opposed wrist pins connected to said chuck, a cross member connected between the upper ends of said uprights, a vertical screw quill adjustably mounted on said cross member,

a cone end member rotatably and removably secured to the lower end of said quill, a traveling bar slidably mounted between said uprights and forming a bearing for the lower end of said screw quill, a pressure arm slidably and swingably mounted .on one of said uprights, a second arm slidably mounted on the other of said uprights and having a threaded outer end, said first arm defining an aperture through which said threaded portion of said second arm extends, an adjusting nut on said threaded portion engageable with said first arm to move said first arm toward said chuck, said adjusting nut and said first arm having cooperative measuring indicia thereon, a compression sprin acting in opposition to said adjusting nut, a tool holder adjustably clamped to said first arm, a knurling wheel mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on one of said uprights and rotatable in a horizontal plane, a radially adjustable crank pin on said crank wheel, a pitman arm connected to said crank pin and selectively engageable with said wrist pins, and flexible bushings positioned between said pins and said pitman arm whereby said arm is easily .tilted to be disengaged from said wrist pins.

'2. Amachine for knurling pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned vertically between said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having diametrically opposed wrist pins connected to said chuck, a cross member connected between the upper ends of said uprights, a vertical screw quill adjustably mounted on said cross member,

a cone end member rotatably and removably secured to the lower end of said quill, a pressure arm slidably and swingably mounted on one of said uprights, a second arm sliclably mounted on the other of said uprights and having a threaded outer end, said first arm defining an aperture through which said threaded portion of said second arm extends, an adjusting nut on said threaded portion engageable with said first arm to move said first arm toward said chuck, a compression spring acting in opposition to said adjusting nut, a tool holder adjustably clamped to said first arm, a knurling wheel mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on one of said uprights and rotatable in a horizontal plane, a radially adjustable crank pin on said crank wheel, a pitman arm connected to said crank pin and selectively engageable with said wrist pins, and flexible bushings positioned between said pins and said pitman arm whereby said arm is easily tilted to be disengaged from said wrist pins.

3. A machine for knurling pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned vertically between said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having diametrically opposed wrist pins connected to said chuck, a cross member connected between the upper ends of said uprights, a vertical screw quill adjustably mounted on said cross member, a cone end member removably secured to the lower end of said quill, a pressure arm slidably and swingab-ly mounted on one of said uprights, means including a screw thread for moving said first arm toward said chuck, a compression spring acting in opposition to said adjusting means, a tool holder adjustably clamped to said first arm, a knurling wheel mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on said machine, a radially adjustable crank pin on said crank wheel, a pitman arm connected to said crank pin and selectively engageable with said wrist pins, and a flexible bushing positioned between said crank pin and said pitman arm whereby said arm is easily tilted to be disengaged from said wrist pins.

4. A machine for knurling pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned vertically between said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having diametrically opposed wrist pins connected to said chuck, a cross member connected between the upper ends of said uprights, a vertical screw quill adjustably mounted on said cross member, a cone end member removably secured to the lower end of said quill, a pressure arm sliclably and swingably mounted on one of said uprights, means including a screw thread for moving said first arm toward said chuck, a tool holder on said first arm, a knurling wheel mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on said machine, a radially adiustable crank pin on said crank wheel, a pitman arm connected to said crank and selectively engageable with said wrist pins, and a flexible bushing positioned between said crank pin and said pitman arm whereby said arm is easily tilted to be disengaged from wrist pins.

A. machine for displacing metal in the side wa ls of pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned vertically between said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having a wrist pin connected to said chuck, a cross member connected between said uprights above said chuck, a vertical screw quill adjustably mounted on said cross member, a cone end member rotatably secured to the lower end of said quill, a pressure arm slidably and swingably mounted on one of said uprights, means for moving said first arm angularly toward said chuck, a tool holder on said first arm, a Wheel tool mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on said machine, a radially adjustable crank pin on said crank Wheel, and a pitman arm connected to said crank pin and engageable with said wrist pin.

6. A machine for displacing metal in the side walls of pistons comprising, a base having a pair of uprights extending thereabove, a headstock positioned verticallybetween said uprights, a piston receiving chuck rotatably mounted on said headstock, a crank member having a wrist pin connected to said chuck, a cross member connected between said uprights above said chuck, a vertical screw quill adjustably mounted on said cross member, a cone end member rotatably secured to the lower end of said quill, a pressure arm slidably and swingably mounted on one of said uprights, means for moving said first arm angularly toward said chuck, a tool holder on said first arm, a wheel toool mounted on said holder and rotatable about a vertical axis, a motor driven crank wheel mounted on said machine, a crank pin on said crank wheel, and a pitinan arm connected to said crank pin and engageable with said wrist pin.

7. A piston knurling machine comprising a chuck rotatable about a vertical axis, adjustable means for oscillating said chuck through a predetermined angular distance, an arm pivoted on said machine and swingable horizontally toward said chuck, a screw member on said machine extending to adjacent said arm, a pressure nut adjustable on said screw member and engageable with said arm to move said arm toward said chuck, a tool holder adjustably mounted on said arm and having a bifurcated end facing said chuck, a vertical pin extending between the bifurcations of said arm and having a bearing portion concentric with the axis of said pin, an eccentric bearing portion on said pin and within. the bifurcated end of said holder, knurling tools rotatably mounted on said bearing portions, a sector bar on said holder having a plurality of locating notches formed therein, and an adjusting lever non-rotatably secured to said pin and selectively engageable in said notches.

8. In a piston sizing machine, a tool holder arranged to be urged toward a piston to be sized, a pin rotatably mounted on the end of said holder, a pair of bearing portions on said pin, one of said bearing portions being eccentric with respect to the other of said bearing portions, a pair or" knurling tools rotatably mounted on said bearing portions, and means for angularly adjusting said pin on said holder.

9. In a machine of the class described, the combination of laterally spaced uprights, a head stock disposed vertically between said uprights and provided with diametrically opposed wrist pins and with a centering chuck adjustable to pistons of different sizes, a rotatably mounted axially adjustable tail stock axially aligned with said head stock and having a conical work engaging face engageable within the open end of a piston mounted with its head end on said tail stock, a driven crank wheel provided with a driven radially adjustable crank pin, a pitman connected to said crank pin and selectively engageable with said Wrist pins on said head stock, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a knurling tool holder adjustably mounted on said tool carrying arm, means for adjusting said tool carrying arm transversely of the work mounted on the other upright for swingable and vertical sliding adjustment thereon and including a manually adjustable threaded connection to the swinging end of the tool carrying arm, and manually actuated means for vertically adjusting said tool carrying arm on the upright on which it is mounted for positioning the tool carried thereby longitudinally relative to the axis of the work.

10. In a machine of the class described, the combination of laterally spaced uprights, a head stock disposed vertically between said uprights and provided with diametrically opposed wrist pins and with a centering chuck adjustable to pistons of difierent sizes, a rotatably mounted axially adjustable tail stock axially aligned with said head stock and having a conical work engaging face engageable within the open end of a piston mounted with its head end on said tail stock, a driven crank wheel provided with a driven radially adjustable crank pin, a pitman connected to said crank pin and selectively engageable with said wrist pins on said head stock, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a knurling tool holder adjustably mounted on said tool carrying arm, and means for adjusting said tool carrying arm transversely of the work mounted on the other upright for swingable and vertical sliding adjustment thereon and including a manually adjustable threaded connection to the swinging end of the tool carrying arm.

11. In a machine of the class described, the combination of laterally spaced uprights, a rotatable work chuck provided with diametrically opposed wrist pins, a driven crank wheel provided with a driven radially adjustable crank pin, a pitman connected to said crank pin and selectively engageable with said wrist pins on said chuck, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a tool holder adjustably mounted on said tool carrying arm, tool feed means for adjusting said tool carrying arm transversely of the work mounted on the other upright for vertical sliding adjustment thereon and including a threaded connection to the swinging end of the tool carrying arm, and manually controlled means for vertically adjusting said tool carrying arm on the upright on which it is mounted for positioning the tool carried thereby longitudinally relative to the axis of the work.

12. In a machine of the class described, the combination of laterally spaced uprights, a rotatable work chuck provided with diametrically opposed wrist pins, a driven crank wheel provided with a driven radially adjustable crank pin, a pitman connected to said crank pin and selectively engageable with said wrist pins on said chuck, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a tool holder mounted on said tool carrying arm, tool feed means for adjusting said tool carrying arm transversely of the work, and manually controlled means for vertically adjusting said tool carrying arm on the upright on which it is mounted for positioning the tool carried thereby longitudinally relative to the axis of the work.

13. In a machine of the class described, the combination of laterally spaced uprights, an oscillatably mounted work chuck, driven means for oscillating said Work chuck through a predetermined arc, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a tool holder adjustably mounted on said tool carrying arm, tool feed means for adjusting said tool carrying arm transversely of the work mounted on the other upright for vertical sliding adjustment thereon and including an adjusting connection to the swinging end of the tool carrying arm, and manually controlled means for vertically adjustig said tool carrying arm on the upright on which it is mounted for positioning the tool carried thereby longitudinally relative to the axis of the work.

14. In a machine of the class described, the combination of laterally spaced uprights, an oscillatably mounted work chuck, driven means for oscillating said Work chuck through a predetermined arc, a tool carrying arm mounted on one of said uprights for vertical sliding and swingable adjustment thereon, a tool holder adjustably mounted on said tool carrying arm, and tool feed means for adjusting said tool carrying arm transversely of the work mounted on the other upright for vertical sliding adjustment thereon and including an adjusting connection to the swinging end of the tool carrying arm.

15. In a machine of the class described, the combination of an upright, a rotatable head stock disposed with its axis in spaced parallel relation to said upright and provided with diametrically opposed wrist pins and with a centering chuck adjustable to pistons of different sizes, a rotatably mounted axially adjustable tail stock axially aligned with said head stock and having a conical work engaging face engageable within the open end of a piston mounted with its head end on said tail stock, a driven crank wheel provided with a driven radially adjustable crank pin, a pitman connected to said crank pin and selectively engageable with said wrist pins on said head stock, a tool carrying arm mounted on said upright for vertical sliding and swingable adjustment thereon, a tool holder mounted on said tool carrying arm, tool feed means for swingably adjusting said arm relative to the work, and means for vertically adjusting said tool carrying arm on said upright for positioning the tool carried thereby longitudinally relative to the axis of the work.

HAROLD P. PHILLIPS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 810,766 John Jan. 23, 1906 960,769 Armstrong June 7, 1910 1,839,775 Rottler Jan. 5, 1932 2,444,017 Croft June 22, 1948 2,593,936 Teetor Apr. 22, 1952

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