US2645149A - Hydraulic copying device for lathes - Google Patents

Description

July 14, 1953 `o. voN zELEwsKY 2,645,149

HYDRAULIC COPYING DEVICE FOR LATHES INVENTQR:

I www" ATTorLNys July 14, 1953 o. voN zELr-:wsKY

HYDRAULIC COPYING DEVICE FCR LATHEs 2 Sheets-Sheet 2 Filed April 18, 1950 INVENTOR'. Uffa/mtr vor; Ze/eA/sx Oil-HLM .ATTURNEHS Patented July 14, 1953 UNITED STATES PATENT OFFICE HYDRAULIC COPYING DEVICE FOR LATHE Sy Ottomar von Zelewsky, Neuhausen am Rheinfall,

Switzerland, assignor to Georg Fischer Aktiengesellschaft, Schaffhausen, Switzerland, a company of Switzerland Application April 18, 1950, Serial No. 156,538 In Switzerland December 2, 1949 z claims. (C1. 8,2-14) templates fixed opposite each other upon the machine frame, said follower actuating the movements of the tool-carrying slide which is movable obliquely to the path of movement of the longitudinal slide.

An object of the present invention is to provide an hydraulic device for machines of this type wherein the follower will cause the change of movement of the copying device and will limit the path of movement thereof.

Other objects of the present invention will become apparent in the course of the following specication.

The objects of the present invention maybe realized through the provision of an auxiliary lever which is connected with the follower and which serves to change the operation of the copying device, while the path of the reciprocatory movement is limited by movable or adjustable stops.

The device constructed in accordance with the principles of the present invention is suitable for machines with intermediate hydraulic flow, as well as for machines for continuous hydraulic flow.

The invention will appear more clearly fromj the following detailed description, when taken in connection with the accompanying drawings showing, by way of example, a preferred embodiment of the inventive idea wherein the subject matter of the invention is illustrated in its application to amachine having a continuous hydraulic flow.

In the drawings: f y

Figure 1 illustrates diagrammatically, partly in vertical, longitudinal section and partly in side elevation, portions of a lathe having a hydraulic copying device which is provided with meansY for changing the copying movement whereby the machine is operable with two templates and two rotary tools;

Figure 3 shows on a still larger scale, and in section, a handleused for actuating the stops;

Figure 4 is a transverse section along the line IV-IV of Figure 3;

.5 Figure 5 is a longitudinal section'along the line V-V of Figure 3.

The copying lathe shown in Figure 1 includes a frame I carrying a headstock 2 and a tailstock 3. A work piece 4 is held between the headstock 2 and the tailstock 3. The frame I carries rails or guides 5 extending in the longitudinal direction.V

A longitudinal carriage or slide 6 is movable upon the guides 5 by any suitable means not shown in the drawings. A differential piston 8is integral 1.5.. with an end piece l, and is attached by bolts Ia to the longitudinal carriage 6. A tool .carriage 9 is mounted upon rails or guides I0 which are nrmly attached to the casing 6. The tool carriage 9 encloses the differential piston 8 and slides upon I 20. the guides I0 obliquely to the direction of rotation of the work piece 4.

In the example illustrated the tool carriage 9 is rmly connected with a tool holder I I which carries a lower tool I2 and an upper tool 25.

It is apparent that the illustrated `tool holder may be conveniently replaced by a holder having a boring tool or rod and one or two inner tools.

Furthermore, an ordinary tool holder carrying a single tool may replace the holder designed for fr", two tools and illustrated in Figure 1.

A steering casing I3, which operates in part as a differential piston, is also located within the tool carriage 9 andis connected therewith by means of a threaded spindle I4 which is screwed 1 f, into the member I3 and extends through the` carriage 9. A wheel I5 is keyed upon one end of the spindle I4 and is located outside of the carriage 9. Due to this arrangement the position of the member I3 in relation to the carriage 9 may be conveniently adjusted by turning the wheel I5.

The casing I3 has a passage formed therein which contains a steering piston or pin I6. A spring il is located at the bottom of this passage and presses the pin I6 'against one end of a link I8. The link I8 is pivoted at 20 intermediate its ends upon the casing I3. The opposite end oi the .link I8 carries the follower I9, which is adapted to slide upon the edges of templates 25 or 'I8. A The carriage 6 is provided with a container 2I 5o for the hydraulic medium, as well as a pump 22.

The pump 22 communicates by a conduit 22a with a :pressure-regulating overflow valve` 23 which is `pressed upwardly by a spring 24.y

The upper template 26 and/or the lower template 18 are mounted upon the machine frame I by any suitable means not shown in the drawings. Furthermore, the illustrated templates may be conveniently replaced by work prototypes.

The piston 8 contains a passage 1I which extends between the pump 22 and the annular space 12 extending around the piston 8. A passage 13 formed in the piston 8 extends between the valve 23 and a chamber 14 located above the piston 8 and between that piston and the carriage 9.

The device for changing the direction of the copying process and for limiting the path of the reciprocatory hydraulic means constituting the subject matter of the present invention is shown in greater detail in Figures 1 and 2 of the drawings, and includes a steering member 21 which is firmly connected with the casing I3 and is provided with an arm 80. An auxiliary lever 28, shown best in Figure 2, is pivoted at 29 intermediate its ends upon the support 21. The lever 28 has one end which projects into an opening provided in the link I8, and the link I8 and the lever 28 carry out minute movements throughout the operation of the machine.

The same pivot 29 carries an auxiliary lever 30, one end of which carries a roller 3l pivotally mounted at 3Ia upon the lever 36. The same end of the lever 30 carries a stop or abutment 32.

A spring 33 is supported by the member 21, and presses against the opposite end of the lever 30, thereby tending to turn the lever clockwise (looking in the direction of Figure 2). The force of the spring 33 is about twice that of the spring I1 (Fig. 1).

It is apparent that the auxiliary lever 30 may be connected directly with the follower link I8.

The longitudinal carriage 6 carries a support 42 and a shaft 34. A setting lever 35, a switching lever 36, an upper link 31 and a cam 38 are all keyed upon the shaft 34 and are movable therewith.

Furthermore, the carriage 6 supports a casing or support 39. A lower link 40 is pivoted at 40a to the support 39. The two links 31 and 40 are joined by a bar 4I. As shown more clearly in Figure 2 of the drawings, the roller 3| is in engagement with the bar 4I so that any changes in the location of the bar 4I will cause the roller 3| and, consequently, the auxiliary lever 30, to change their positions.

The support 42 of the shaft 34 is hollow and contains a spring 43 which presses against a projection 44. The projection 44 is engaged by the cam 38 when the lever 35 is actuated so that it can serve as a stop.

IThe support 45 is firmly connected with the longitudinal carriage 6. A threaded spindle or shaft 46 carries an upper stop 41. Similarly, a threaded spindle or shaft 48, extending parallel to the shaft 46, carries a lower stop 49.

The upper ends of the shafts 46 and 46 are supported in the member 45, while the lower ends are carried by the support 39.

The spindle 46 is rmly connected with a cone gear 46a which meshes with the cone gear 50 rotatable along with the shaft 52. The shaft 52 is rmly connected with a handwheel i. Thus, by turning the wheel 5I the shaft 46 will be rotated so that the position of the upper stop 41 can be adjusted vertically.

The support 45 also carries a shaft 55 which actuates the spindle 48 by means of meshing gears 53 rand 48a. A handwheel 54 is keyed upon one end of the shaft 55. Therefore, by turning the handwheel 54 the position of the lower stop 4 49 upon the spindle 48 can be vertically adjusted.

A shaft 56, which is indicated diagrammatically in Figures l and 2, extends parallel to the rotation axis of the work piece 4, and is attached to the frame I by any suitable means not shown in the drawings. A stop link 51 may be held rmly in any suitable location upon the shaft 56 by means of the set screw 58.

In the course of the movement of the longitudinal carriage 6 from right to left (looking in the direction of Figure 2) the lever 36 may strike the stop link 51 and will then move from the position shown in full lines in Figure 2 to the position shown in broken lines. The switching operation caused by this movement of the lever 36 will be described in greater detail hereinafter.

Figures 3, 4 and 5 show parts of a device which makes it possible to adjust the depth of the cutting operation carried out bythe tool.

The shaft 52 extends through a ring 59 which is loosely mounted thereon and which carries' a scale 59a (Fig. 3). The handwheel 5I has an extension 5Ia which contains passages Bla. Pins 6I are located in the passages 61a and are pressed by springs 60, which are also located therein, against the ring 59. Due to this arrangement the ring 59 is pressed against a flange 62 of the shaft 52.

The machine illustrated by way of example, has three adjustable abutments 64 (Fig. 4) which are located in an annular groove 63 which is T-shaped in cross-section. The groove 63 is formed in the portion 5Ia of the handwheel 5I, and the abutments 64 have flanges fitting into the grooves. The abutments 64 may be held rmly in selected positions in the groove 63 by set screws 65 which are screwed into the abutments 64 and which may be pressed against the bottom of the groove 63.

It is apparent that the number of abutments 64 may be varied at will. As will be explained in greater detail hereinafter, the abutments 64 make it possible to vary adjustably the depth of the cutting operation.

The support 45 (Fig. 3) is integral with a guide 66 which carries a stop 61. A pin 10 has one end which extends into a passage 66a provided in the member 66. The inner end of the pin 10 carries a piston 10a. A spring 69 encloses the pin 10 and presses with one end against the piston 10a, while its other end is pressed against the bottom of the recess 66a formed in the member 66. Due to this arrangement the stop 61 is pressed in the direction against the casing 45. However, the stop 61 can be rmly held upon the member 66 through the use of set screw 68.

As shown more clearly in Figure 5, the part ofv the stop' 61 which faces the abutments 64 is provided with an inclined surface 19 which may be engaged by the abutments 64.

The operation of the illustrated hydraulic steering device is as follows:

The pump 22, which operates continuously, withdraws the pressure medium from the container 2I and transmits it through the conduit 22a and the passage 1I into the annular chamber 12, located below the diierential piston 8. The overflow and pressure-regulating valve 23 maintains constant the pressure in the annular cham-v ber 12, and the pressure medium transmitted by the pump 22 flows simultaneously through the opening of the valve 23 and the passage 13 into the space 14. 'I'hence the pressure medium flows through the passage toward the pin I6. If the edge 16 Vof the pin I6 is raised the pressure medium will flow from the passage 15 to the passage 11a and thence through the passage 11 and the conduit 11bfback into the container 2|.

As a result of this continuous flow the steering device operates in accordance with the'following principles: l*

Since the -differential piston 8 is firmly connected with the longitudinal carriage 6, the toolcarrying carriage 9, which serves as a cylinder for the piston 8, will move'upon the piston 8, de-V pending on pressure conditions prevailing in the chambers 12 and 14 below and above the piston.

The constant pressure prevailing in the vannular chamber 12 may be set by means of the pressure-regulating valve 23, while the pressure in the space 14 is determined by the position of the edge 16 of the pin I6 since this position determines the amount of ow past the pin I6. When the edge 16 moves upwardly, thereby increasing the area of the flow, the pressure in the space 14 will drop so that the carriage 9 withthe toolholder II will slide downwardly.

On the other hand, when the edge 16 moves downwardly the pressure in the space 14 will increase and the carriage 9 will move upwardly. 1f pressure conditions in the chamber 12 and the space 14 are such that forces exerted upon the carriage 9 are in balance, the carriage 9 will remain without moving in a certain position.

The pin I6 is moved to the extent of a few hundredths of a millimeter during these operations, and it is'always pressed downwardly by the spring I1 so that it has the tendency of closing the passage for the flow of the hydraulic medium. The lever I8 which presses upwardly against the pin I6 can be influenced `in many ways. The following operational possibilities are available in the course of the operation of the described machine:

A. Copying of outer surfaces When outer surfaces are to be copied the rotary tool I2 is mounted in an ordinary Iholder which is not shown in the drawings and which replaces the holder I I of Figure 1. The template 26,

moving downwardly the operative edge 16 of the pin I6.

When the follower I9 is' in engagement with edges of the template 26 which are parallel to the axis of rotation of the work piece 4, the lever I8 will not move so that the tool carriage 9 re- Y mains inthe state' of equilibrium. At that time which is used in this operation, is located above the follower I9 so that the edges to be copied are situated upon the lower side of the template 26. In that case the lever is located in its upper position, shown in full lines in Figure 2. The links 31 and 40, which are actuated by the lever 35, hold the bar 4I in a position in which it presses against the roller 3| ofthe auxiliary lever and thereby raises the stop 32 from contact with the auxiliary lever 28. Thus, the auxiliary lever 38 remains inoperative during the copying of a template 26 situated in an upper position. It is apparent that the diminishing of the profile of the template 26 corresponds to a diminishing of the diameter of the work piece 4 being treated. v

When this takes place the follower I8 will be rotated clockwise about the axis 20 (looking in( turn counter-clockwise about the pivot 20 since diminish lthe diameter of the work piece 4. The

cylindrical surfaces are produced upon the work piece 4.

B; Copying of outer'surfaces with the upper' tool 25 A tool 25 located ina-n upper position upon the tool-holder II and which is used for turning outer surfaces, is employed in conjunction with a template 18 located below the follower I9 and having an upper edge'which is engaged by the follower in the course of the copying operation.` Then the lever 35 is located iny its downward position. The location of the levers 35 and 36,/ the links 31 and 4I), the cam 38, the bar 4I, the lever 30, the roller 3I 'and the stop 32 is indicated by broken lines in Figure 2. .Thus `the stop 32 of the auxiliary lever 30 presses against the auxiliary lever 28 and tends to turn it clockwise (looking in the direction of Figure 2f). Thenthe end ofthe lever 28, which is in engagementwith the lever I8, will press thelever I8 againstthe pin I6 and will move the pin I 6 upwardly, thereby compressing the spring I1. Then a considerable space will .be open for the flow of the pressure medium so that the tool slide 9 will move downwardly until the follower I9 strikes the edge of the lower template 18, or until the auxiliary lever 28 strikes the lower stop 49.

.In the course of the described procedure ofl employing the lower Vtemplate 18 and the upper tool-25 for working uponouter surfaces, a diminishing profile ofv the template 18 will result in an increase of the diameter of the work piece 4, while an increasing prole of the template will spring 33 which presses'against yan end of the auxiliary lever y33 isoperative and contributes greatly to rmaintaining the flow of the pressure medium past the pin I6.

c. Withdrawn' of me fooi Let it'b'e assumed that' during the copying of the upper template 26, and while the tool I2 is in engagement with the work piece 4, the tool I2 must be withdrawn from such engagement in a predetermined Vposition upon the work 4. In order to" achieve vthis the tool slide 9 must be moved downwardly. The downward movement is accomplished by the use of the stop ring 51 which` is placed in the required position upon the sh'aft' 56"and is held thereon by the screw 58.

It is apparent that the longitudinal carriage 6 moves from right to left, while the work piece 4 is being produced. l The lever 36 is then in the position shown in full lines in Figure 2. The po respective positions shown by broken lines in Figure 2. The stop 32 will then engage the lever 28 so that the pin I6 will be moved upwardly. The iiow past the pin I6 will increase and the tool slide 9 will move downwardly until the auxiliary lever 28 strikes the stop 49 whereupon the parts will remain in equilibrium.

D. Use of the tool 12 for cylindrical surfaces Obviously the machine can be used for producing cylindrical surfaces upon the work 4 by means of the tool I2 and without utilizing any of the templates or prototypes.

The operator will turn the handwheel 5|, thereby rotating the shaft 52, the gears 50 and 46a and the threaded shaft 46 until the upper stop 41 is moved to a desired position for producing upon the work piece 4 a cylindrical surface of the desired diameter. The lever 35 is then located in its upper position, shown by full lines in Figure 2. The follower I9 and its lever I8 remain inoperative and the position of the operating pin I6 is determined by the lever 28 which will be in engagement with the stop 41. As soon as the operation is completed the tool I2 can be moved out of contact with the workpiece 4, by lowering the carriage 9. This is accomplished by turning the handwheel 5I counter-clockwise and thereby shifting the stop 41 so that the pin I6 will move upwardly.

E. Simultaneous use of upper and lower templates The described machine can also be utilized for treating the work piece 4 in accordance with the profiles of the templates 26 and 18 which complement each other in that case. Then the tool holder I I is utilized which, as shown in Figure 1, carries an upper tool 25 and a lower tool I2. In the course of the movement of the carriage 6 from right to left the lower tool I2 is in engagement with the work 4 and the follower I9 moves along the operative edge of the template 26. The lever 35 is then in its upper position, s'hown in full lines in Figure 2. When the tool I2 of the illustrated form is utilized and when the angle of inclination of the carriage 9 is as i1lustrated, the tool I2 will not cut that portion of the work piece 4 which is indicated by the numeral 82 in Figure 1. When the tool I2 reaches the left end of the work piece 4, the lever 35 is moved downwardly by the operator to the position shown by broken lines in Figure 2. Then the carriage 9 will slide downwardly and the follower I9 will be brought into engagement with the upper operative edge of the lower template 18. The movement of the carriage 6 is then reversed and the upper tool 25 will be brought into engagement with the work piece 4. It is apparent that the upper tool 25 can cut the p0rtion 82 of the work piece 4. Thus, the change from the lower tool I2 to the upper tool 25 can take place without changing the position of the work piece 4. No subsequent operations are necessary.

The immovable arm 80 is used to limit the downward movement of the slide 9 which may be caused by its weight when there is not sufficient fluid pressure to counteract it. In the course of such downward movement, first the auxiliary lever 28, which is now inoperative, and thereafter the arm 80 are brought into engagement with the lower stop 49. The entire weight of the device rests upon the arm 80 so that no pressure is exerted upon the follower, the auxiliary levers or the templates. This limitation of the downward movement of the slide 9 is also necessary when inner surfaces of a work piece are being treated since in the event pressure drops suddenly the holder of an inner tool would strike the inner walls of a work piece and would be likely to damage them.

The device shown in Figures 3, 4 and 5, which is used for varying the cutting depth may be used when, for example, the outer surfaces of a, work piece 4 are cut by the tool I2 following the outline of a template 26 and the amount of material to be cut is so great that the tool cannot cut to the required depth in a single operation.

The device is employed as follows:

The stops 64 (Fig. 4) are used in numbers corresponding to the number of the required cutting operations. The stops 64 are inserted into the annular groove 63 (Fig. 3) and are fixed in their positions by the set screws 65. The distances between the stops G4 can be read upon the scale 59a of the ring 59 which can be turned so that the scale 59a is set to zero. Obviously the distances between the individual stops 64 are proportional to the depth of cutting operations.

After the rst cutting operation has been completed by the tool I2 the handwheel 5I is pressed downwardly in the direction of the arrow 5Ib, thereby compressing the springs 60 and moving the stops 54 below the abutment 61. Then the wheel 5I is turned clockwise until the second stop 54 engages the inclined surface 19 of the stop or abutment 61. The turning of the Wheel 5I will also rotate the threaded shaft 46 through the intermediary of the shaft 5a, and the gears 5G and 45a so that the stop 41 will move upwardly upon the shaft 46 to the desired extent. This will make it possible for the carriage 9, carrying the tool I 2, to move further upwardly to the desired extent. This procedure is repeated at the end of each longitudinal stroke of the carriage 6 until a work piece is cut to the desired diameter. Thereupon, the upper stop 41 is moved back to its position for the initial cutting depth by turning the handle 5I counterclockwise. It is apparent that the stops 64 will slide upon the surface 'I9 of the stop 61, which is engaged by the spring 69, and will press the stop 61 outwardly so that it will be inoperative.

When the setting of the cutting depth is not desired the stop or abutment 61 is pulled outwardly and is fixed in that position by turning the set screw 68. Then the handwheel 5I can be turned at will since the stops 64 will not be engaged oy the stop 61. In that case th-e extent of adjustment of a tool can be read upon the scale 8l, provided upon an outer surface of the slide 5Ia which is integral with the wheel 5I (Fig. 3)

It is apparent that the example shown above has been given solely by way of illustration and not by way of limitation, and that it is subject to many variations and modifications without departing from the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. In a lathe, having a slide movable up and down, a piston connected with said slide and movable therewith, and an auxiliary, two-armed lever pivotally mounted in said piston; another two-armed lever pivotally mounted in said piston, a spring pressing against one arm of the second-mentioned lever, a pin carried by the second arm of the second-mentioned lever and adapted to be pressed by said springagainst the second Y arm of the first-mentioned lever, a roller carried by second arm of the second-mentioned lever, means adapted to engage said roller and thereby shift the position of said slide, two stops movable into the ,path of the other arm of the secondmentioned lever for limiting the upward and the downward movements, respectively, of said slide, shafts operatively supporting said stops, gears engaging said shafts and handwheels connected with said gears for actuating the same.

2. In a lathe, having a slide movable up and down, a piston connected with said slide and movable therewith, and an auxiliary, two-armed lever pivotally mounted in said piston; another two-armed lever pivotally mounted in said piston, a spring pressing against one arm of the second-mentioned lever, a pin carried by the second arm of the second-mentioned lever and adapted to be .pressed by said spring against the second arm of the rst-mentioned lever, a roller carried by second arm of the second-mentioned lever, means adapted to engage said roller and thereby shift the position of said slide, two stops movable into the path of the other arm of the second-mentioned lever for limiting the upward and the downward movements, respectively, of

said slide, shafts operatively supporting said stops, A

separate gears engaging said shafts, a handwheel connected with one of said gears for actuating the same, means connected with the other one of said gears for actuating the same, and means connected with the `last-mentioned means for setting the same to a plurality of positions.

OTTOMAR voN ZELEWSKY.

References Cited in the le of this patent UNITED STATES PATENTS Number Name l Date 610,981 Whiton Sept. 20,- 1898 1,677,131 Cole July 17, 1928 2,063,414 Tweddell Dec. 8, 1936 2,169,135 Brandenberger Aug. 8, 1939 2,176,700 Bckel Oct. 17, 1939 2,331,443 Von Zelewsky Oct. 12, 1943 2,437,570 Von Zelewsky Mar. 9, 1948 2,468,325 Eisele Apr. 26, 1949

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