US2423932A - Gear rolling machine - Google Patents

Description

July 15, 1947. H. FINZEL GEAR ROLLING MACHINE Filed Dec. 15, 1944 4 Sheets-Sheet l July 15, 1947. H. FINZEL GEAR ROLLING MACHINE Filed Dec. 15, 1944 4 Sheets-Sheet 2 mm he 8 mm 8 a July 15, 1947. H. FINZEL GEAR ROLLING MACHINE Filed D80. 15, 1944 4 Sheets-Sheet 3 any Ill...

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E Q QQ nm on on Patented July 15, 1947 PATENT OFFICE GEAR some MACHINE Herman Final, Chicago, Ill., assignor to N. H.

Well, Ralph Well, and George Well, all of Ohicago, 111., as trustees Application December 15, 1944, Serial No. 588,321

12 Claims.

The present invention relates to a method of and apparatus for rolling gears.

Heretofore gear rolling machines have been proposed in which a preheated blank is put into the machine and a die roll is fed towards the blank to sink the teeth into the blank. It has also been proposed to oscillate the die roll and the blank during the rolling process, so as to insure symmetrical teeth and to rotate the blank and the die roll continuously in the same direction after the teeth are formed, so as to planish the teeth and produce thereon a tough smooth surface.

In the machines proposed heretofore the power for clamping the blank in the machine, for feeding the die roll into the blank and for rotating the die roll and the blank,'was supplied by a single driving motor, the difierent motions being obtained by means of cams, toggles, reversing gears, clutches and belts, connected between the driving motor and the various power driven elements of th machine.

However, gears of different size or of diiferent materials require different rates of feed of the die roll towards the blank relative to the speed of rotation of the die roll and blank, but with a single driving motor for the entire machine such difl'erent ratios are only attainable by complicated speed change devices requiring a multiplicity of gears in the power trains between the single driving motor and the various driven parts of the machine. This is objectionable because the unavoidable back lash affects the accuracy of the work, nor permit such speed gears to vary the speed of one element relative to the other in a continuous manner during the operating cycle of the machine.

An object of the present invention is to avoid the aforementioned disadvantages.

A further object is the addition of novel and advantageous features by providing for an independent motor drive for each of the principal functions of the machine, and independent adjustment, if necessary, of the speed of these motors during the operating cycle. By providing independent motors for each of the main motions of the machine the speeds of the different elements relative to each other may be varied independently during the operating cycle, which is a very desirable feature resulting in great economy in time, as will be pointed out hereinafter.

In the machines heretofore proposed, a preheated blank is put into the machine and is then rolled. To produce a, highly finished gear by rolling at high temperature it is essential to cool the die roll during the rolling process,'so as to 2 prevent formation of scale on the blank and its adhesion and building up on the die roll, which greatly impairs the accuracy and finish of the completed gear. As a, result the blank is rapidly g cooled, the power for rolling increased, and the finished gear is inaccurate as to dimensions and requires further finishing operations after it is removed from the machine.

A further object of the present invention is to lo provide for heating of the gear blank to the proper temperature and maintaining said temperature during the entire rolling process, while at the same time the die roll is cooled. The loss of heat from the blank to the die roll is comll pensated by the supply of heating energy during the rolling process.

Another object of the invention is to provide for automatic control of the various functions of the machine so that upon initiation of the rolling cycle by the insertion of a blank it is completed in the desired manner without further interference of the operator.

The invention has the further object to provide for surrounding the blank during the rolling process with a neutral atmosphere so as to prevent oxidation and scaling. If desired a gaseous carburizing or nitriting agent may be employed to treat the gears upon completion of the rolling and while the finished gear is still in the machine.

0 The invention further provides means to protect the various parts of the machine from the heat supplied to the blank, so as to avoid distortions in the machine during the rolling process, which may cause serious dimensional changes and may lead to inaccuracy of the finished product.

Asthe rim of the gear blank is in a plastic state during the rolling process it is necessary, particularly on small blanks where the temperature of the hub is nearly the same as that of the plastic circumference, to protect the hub from undue axial clamping pressure to prevent its deformation, and the present invention provides means for adjustment and limitation of the pressure to a desired value.

While the following description of the construction and operation of a machine embodying the invention contemplates the rolling of gears at an elevated temperature of the gear material,

it will be apparent that the machine may also be employed for rolling gears of materials which are plastic at normal temperature, such as certain bronzes. In such cases certain elements for heating and cooling may be omitted or their operation may be suspended.

Other features and advantages of the system will appear from the following .description and the accompanying drawings.

The accompanying drawings show an embodiment of the invention adapted for rolling spur gears, including certain modifications of which the machine is capable. In the drawing,

Fig. 1 is a horizontal section of a gear rolling machine along the lines of Fig. 3.

Fig.'2 is a section of a part of the machine along the lines 2--2 of Fig. 1, to which is added a means for heating the blank during rolling and for subsequent cooling thereof.

Fig. 3 is a vertical section through the machine along the line 3-3 of Fig. 1.

Fig. 4 is a vertical section along the line 4--4 of Fig. 1.

Fig. 5 is an enlarged section of the holding and driving means for the blank shown in Figs. 1, 3 and 4.

Fig. 6 is a modification of the die shown in Fig. 1.

Figs. 7 and 8 comprise a diagram of the circuits and apparatus for the electric control of the machine shown in Figs. 1 to 5.

Referring to Figs. 1 to 6, inclusive, the same illustrate a machine having a compact rigid frame or bed plate 28, on which a shaft or spindle 2| is rotatably mounted on roller bearings 22 and 23. A second shaft 24 is rotatably mounted in axial alignment with the shaft 2| in bearings 25 and 26. These bearings in turn are mounted one near each end of a hollow piston 21, which is arranged for reciprocatory sliding engagement within a cylinder 28, forming a part of the frame 26. The cylinder 28 is provided with anti-friction rings or liners 29 and 36, for reducing the sliding friction between the cylinder 28 and the piston 21.

As shown in detail in Fig. 5, one end of the shaft 2| is provided with a central counter bore 3| to receive the reduced end of a generally annular jaw 32. The jaw 32 has a circular concentric bore 33, through which passes the shank of a headed pin 34, the head of which abuts the inner end surface of the jaw 32. Interposed between the head of the pin 34 and the bottom of the counterbore 3|, is a spring 35, which urges said pin 34 outwardly, but which permits it to yield to a pressure tending to move it inwardly. The bore 33 may be enlarged at the outer face of the jaw 32 as shown at 36, to receive the hub of agear blank.

The shaft 24 is provided with a jaw 31 which is similar to the jaw 32, except for differences in dimensions of the enlarged bore 36, to conform to the other end of the hub of the gear blank. The jaw 31 is also provided with a headed pin 38 similar to the pin 34, but the pin 38 is held rigid in the jaw 31 and is not arranged to slide longitudinally in response to an axial pressure thereon.

As best shown in Figs. 1 and 4, the shaft 2| is provided, at the end opposite to that on which the jaw 32 is mounted, with a bevel pinion 39, which engages a bevel gear 48, th latter being rotatably mounted in a pair of bearings 4| on the frame 29. The gear 46 is coupled to a splined shaft 42, the rearward extension of which is journaled in twin bearings 43 mounted on the frame 20. A spur gear 45 is fastened to the rear end of r connected by multiple V-belts 5| with a pulley 52, of a reversible motor 53 for rotation of the shaft 41 in opposite directions. If desired a magnetic brake (not shown) which is energized for release upon energization of the motor 53 may be mounted on the shaft 47 or on the shaft of motor 53.

Rigidly supported in the frame 2|) and parallel to the shaft 42 are one or more upper guide bars 54 and lower guide bars 55, for guiding a slide block 56, which slide block supports the shaft for the rotating tool of the machine. The slide block 56 is movable transversely to the axis of the shafts 2| and 24 in a horizontal direction.

Rotatably mounted on the slide block 56 in bearings 61 and 58 is a shaft 59 which carries the tool or die 68. The shaft 59 is provided with a bevel gear 6|, which is adapted to engage a bevel gear 62. The beveled gear 62 is rotatably mounted by means of bearings 63 on th slide block 56 concentric with the shaft 42. The hub of th gear 62 is provided with a splined hole arranged for sliding engagement with the splined shaft 42. The slide block 56 may be driven forward at a slow rate of speed by a feed motor 64 and moved backward by a retracting motor 65. The arrangement being as follows: The block 56 is provided with a threaded bushing 66, having its central axis at right angles to and in the horizontal plane of the shafts 2| and 59, as best shown in Fig. 3. A screw 61 is threaded for engagement with said bushing 66. The outer end of the screw 61 is provided with thrust collars 68 and 69 and is supported from the frame 20 by a pair of thrust bearings 10, which engage the collars 68 and 69, to permit rotation of the screw 61 and to move the slide block 56 in one direction or the other, the thrust bearings opposing the horizontal thrusts due to such movement. The screw 61 is suitably coupled to a shaft I0, which shaft is in axial alignment with the screw and arranged to transmit its rotation to the screw. The shaft 10 is in turn supported by a. sleeve II, which latter is rotatably supported by bearings 12 and 13, on the frame 2|]. The sleeve H has keyed thereto a worm gear 14. A driving worm 15 is mounted on a shaft 16 in driving engagement with the worm gear 14. The shaft 16 also has fastened thereto a pulley H which is connected by means of V-belts 18, to a pulley l9, keyed to the shaft of the motor 64. Thus when the motor 64 rotates it causes rotation of the worm 15, worm gear 14, and sleeve Keyed to the sleeve H is a bevel gear 80, of a set of planetary gears 8|. Th'e bevel gear is engaged by one or several-planet gears 82 of said gear set 8|. These planet gears are rotatably supported on stub shafts 83, which in turn are fastened to a casing 84 of the gear set 8 and to a hub 85 fastened to the shaft ID, the casing 84 in turn being rotatably supported by bearings 86. The gear set includes another gear 81 which is in engagement with the planet gears 82. The gear 81 is keyed to a shaft 88, which shaft is rotatably supported on the frame 20 by bearings '89. Also keyed to the shaft 88 is a belt pulley 98 which is connected by means of a V-belt 9| to a pulley 92 keyed to the shaft of the motor 65. The motor 65 is further provided with a brake 93. which brake is energized for release upon energization of the motor 65.

The arrangement as described thus far opcrates in the following manner: It is assumed that a suitable controller is provided for alternate energization of the motors 64 and 65. After \s the main drive of the machine has been started,

a workpiece W has been placed in the machine and the shafts 2I and 99 are rotating, the motor 64 is energized while the motor 95 remains deenergized. As the brake 93 prevents rotation of the armature of the motor 65, the gear 91 remains stationary. while the gear 99 and with it the gears 82 rotate. This causes rotation of the casing 34 and with it of hub 35, in a well known manner, thereby rotating the shaft 19 at a slow speed. This rotates the screw 91 to feed to the slide 59 towards the work. When the slide 59 has been moved to the desired extreme inward position the motor 64 may be deenergized by operation of the manual control referred to or the machine may be provided with a limit switch which, depending upon the position attained by the slide block 59 cuts off the motor 94 and brings the machine to rest. The operator may then manipulate the controller to energize the motor 65 and simultaneously release the brake 93. This causes rotation of the gear 91 while the gear 99 stands still. The casing 94 will now rotate in the opposite direction thereby causing reverse rotation of the shaft 19 and of the screw 61 to retract the slide block 56 from the work. As the motor 65 is connected to the shaft 19 with a much higher transmission ratio than the transmission ratio between the motor 64 and the sleeve 1|, the return movement of the slide block 59 will be at a more rapid rate than the forward movement. It also should be pointed out that the motor 94 does not require a brake as the transmission ratio of the worm gear 14 and the worm 15 and the lead angle of the worm are such, that the reverse torque delivered to the sleeve 1I, through the planetary gear set does not overcome the static friction of the worm gear drive, so that the latter is self locking against reverse power torque.

It will of course be apparent that a limit switch may also be provided upon the slide block 56 for actuation in its extreme outward position,

that is, the position shown in dotted lines in Figs. 1 and 3, in which position the motor 65 and the brake 93 will be deenergized to bring the slide block promptly to rest.

As shown in Fig. l, the die roll 69 is a disc shaped gear of the desired tooth form having a width equal to the width of the finished gear.

Supported on the slide 56 by means of brackets 94, one on each side of the die roll 69, are a pair of rollers 95. The rollers are rotatably supported on pivot pins 94a. The distance between the rollers is equal to the desired width of the finished gear. The supports may be arranged in such a manner that the center distance ofthe rollers may be varied to conform to different widths of gears. As the workpiece W and the die roll 69 rotate they cause the rollers 95 to be rotated by the contact friction, while the rollers prevent the plastic material of the workpiece from being squeezed out sideways and assure that both flanks of the gear teeth have smooth surfaces and that the finished gear teeth have the desired width. The illustration shown is intended merely to illustrate the principle, it being obvious that the specific arrangement for mounting of the rollers 95 may be varied and under conditions it may be desirable to provide theserollers with a positive power drive. Furthermore, the rollers may be adjustably supported from the stationary frame 29 of the machine.

Fig. 6 shows a modification of the die roll shown in Fig. 1. In Fig. 6 the die roll 96 is provided with circular flanges 91 of larger diameter than the die gear and these flangesare spaced apart a distancequal to the desired width of the teeth of the finished gear. The flanges confine the plastic metal during the rolling to prevent the formation of fins at the edges of the Bear teeth. I

The workpiece or blank W is held in the machine-as will now be described. As shown in Fig. 4, a gear sector 99, is pivotally supported on the frame 29 by a pivot pin 99. The teeth of the sector 99 are arranged to engage corresponding teeth I99 which are cut into the surface of the cylinder 21, parallel to its axis, so that upon oscillation of the gear sector 99, the cylinder 21 and the shaft 24 are reciprocated axially toward and 'ported on the frame 29'.

away from the shaft H. The gear sector 93 has a rearward extension I9I which is provided with a pin I92 for pivotal attachment of one link I93 of a toggle. The other link I94 of said toggle is pivotally attached to the link I93 by means of a' pin I95, while the other end of said link I94 is pivotally supported from the frame 29 by a stationary pivot I99. The toggle formed by the links I93 and I94 is operated by means of a hydraulic cylinder I 91 of suitable construction. The cylinder I91 is pivotally supported on a pin I99 mounted on a block I99, which in turn is sup- An adjustable piston rod II9 of the cylinder I91 is pivotally attached to the link I94 by means of a pin III. Thus by supplying compressed fluid alternately to opposite ends of the hydraulic cylinder I91, the toggle is straightened out or collapsed, thereby rocking the gear sector 93 and reciprocating the shaft 24 as will be apparent. The operation of the hydraulic cylinder I91 may be controlled by means of a reversing valve of suitable construction. By providing the piston rod II9 with an adjusting nut H2 or other suitable means its length may be varied, thus'enabling adjustment of the maximum clamping pressure exerted by the toggle on the workpiece W.

The machine may be provided with automatic means to remove the workpiece W from the jaws 32 and 31, such means being illustrated in Figs. 4 and 5. In the construction shown therein the hub on the side of the workpiece W which engages the jaw 31 is much longer than the hub which engages the jaw 32. Therefore, the friction between the former hub and the jaw 31 is greater and upon separation of the jaws 32 and 31, the workpiece W follows the jaw 31 and is withdrawn from the jaw 32 until it abuts a stripper II3 which is attached to the cylinder 29 which forms a part of frame 29 of the machine. This stripper limits the lateral motion of the workpiece W so that it is pulled out of engagement with the jaw 31 and pin 38, when the shaft 24 is withdrawn, whereupon the workpiece may be dropped into a suitable receptacle.

Fig. 5 also shows a. further modification for maintaining the shafts 2| and 24 at a low temperature, so as to prevent overheating of the bearings and other parts of the machine which support said shafts. As the workpiece W is maintained at a high temperature during the rolling process, part of its heat is conducted away by the shafts 2| and 24 toother parts of the machine and this may cause serious overheating of the bearings and of said shafts with the result that the bearings are rapidly destroyed and the accuracy of the work of the machine suifers. Such difficulties are overcome in the following manner: The ends of the shafts 7 I 2| and 24 nearest to the workpiece W are surrounded by sleeve III. The sleeve for shaft 2| is bolted to the frame 20 and that for shaft 24 is bolted to the piston 21. The outer ends of the respective sleeves Ill fit closely around the respective shafts 2| and 24, but the respective sleeves have enlarged bores throughoutthe major portion of their extent. Mounted inside of said bores near both ends thereof are packing rings 5 and H6. A circular space H1 is left between the packing rings and arrangements may be made whereby conduits supply a cooling fluid to pass through these circular spaces to thereby conduct heat away from the shaft and prevent such heat from passing to the bearings 22 and 25, respectively. As the shaft 20 and its supporting piston 21 are movable laterally it will of course be necessary to provide a flexible connection in the conduit for the circular space I H of the sleeve surrounding the shaft 24. Such connection is not shown as its construction will be obvious to any one skilled in the art.

The cooling means for the shafts 2| and 24 just described further insure that the heat transmitted from the blank to the jaws 32 and 31 is quickly withdrawn, thereby also rapidly cooling the central part of the blank W so that only the rim of the blank is maintained in a plastic state whereas the hub is not deformed during the rolling operation of the gear teeth.

Fig. 2 shows an arrangement for heating the blank W during the forming of the teeth and for subsequent cooling thereof. Arranged about the axisof the shaft .2|, and mounted on the sta- Y Part of the machine are a suitable numberof nozzles I III, which are supplied with a suitable heating fluid and which are arranged so that the flame thereof impinges upon the circumference of the blank W while the blank is rotating. The number of nozzles depends upon the diameter of the blank, the working temperature and the type of fuel used. The nozzles and the blank are preferably enclosed in a hood 9 to conserve heat and to prevent the free access of air which may cause oxidation and scaling of the workpiece during the rolling process. The hood is rigidly fastened to the machine frame and is provided with an opening I20 of sufllcient size to permit the movement of the die 60 into and out of engagement with the blank W.

If desired the hood may be supplied through an additional nozzle |2| with a neutral gas which completely envelops the blank W so as to further prevent oxidation of the blank. After the die 60 has reached its innermost position so that the teeth on the blank W are fully formed, it may be desirable to discontinue the heating of the blank which may be accomplished either manually by the operation of suitable valves in the fuel supply for the nozzles H8, or the valves may be operated automatically in connection with the automatic control of the entire machine as will be explained hereinafter.

Under certain conditions it may further be desirable to cool the blank W after the forming process and before it is removed from the machine. This may be accomplished by supplying a cooling fluid through additional nozzles I22, or the supply of the cool neutral gas through the nozzle |2| may be increased so that a strong stream of such gas impinges upon the finished gear W to cool the same at a rapid rate.

The supply of cooling fluid may also be controlled by suitable control valves operated automatically as has been explained heretofore.

8 It will further be obvious that instead of using the gas heating means described other heatin means may be employed such as induction heating, in which case the nozzle 0 would be re-v laced by a suitably shaped primary coil which induces secondary currents in the blank to heat the same. The method of heating a blank by induction is well known in the art. It is par-. ticularly suitable in the present case because it makes it possible to cause the heat developed in the blank to penetrate only so far in a radial direction that the rim is sufllciently plastic for ready formation of the teeth while the hub of the blank is relatively cool and rigid to avoid distortion thereof.

The electrical system for controlling the machine is illustrated in Figs. 7 and 8. Power is supplied from the lines LI and L2, of a direct cur.. rent power supply. The controller comprises double throw push button operated switches 200, 20|, 202, 203. Each of these switches is provided with two normally open contacts 200a, 20Ia, 202a, 203a, and 20017, 20lb, 202b, and 203b, respectively. so arranged that either one or the other of the contacts of the respective switch may be closed. There are also provided flve normally open starting push button switches 204, 205, 200, 201, and 208, respectively, and three normally closed stopping push button switches 20!], 2|0, 2| l, and 2|2. The main motor 53 comprises an armature 53a, and a shunt field winding 53b, the latter being controlled by a rheostat 530. The armature 53a is controlled by a pair of electromagnetic reversing switches 2| 3 and 2M, respectively. The forward switch 2|3 is provided with an energizing coil 2 3a, normally open main contacts 2 |3b and 2 l 30, and normally closed auxiliary 'contacts 2|3e and normally open auxiliary contacts 2 l3). The reverse switch 2 I4 is provided with an energizing winding 2|4a, normally open main contacts 2|4b and 2| 4c, normally closed auxiliary contacts 2|4e and normally open auxiliary contacts 2|4f. The terminals of the motor armature 53a, are connected in the conventional manner to the main contacts of the switches 2|3 and 2, so that upon alternate energization of the two switches the motor is connected to rotate in the forward or reverse direction, respectively. The feed motor 64 is controlled by an electromagnetic switch 2| 5, having an energizing winding 2|5a, and normally open main contacts 2|5b and 2|5c, by means of which the feed motor armature 60a may be connected to the lines LI and L2, when the switch 2|5 is energized. The switch 2|5 is further provided with normally open auxiliary contacts 2|5e and normally closed auxiliary contacts 2|5f and 2|5g. The return motor 0'5 is controlled by an electromagnetic switch 2|6, which is provided with an energizing winding 2|6a, and normally open main contacts 2|5b and 2|6c, for connecting the motor armature 65a to the lines LI, and L2, when the switch 2|6 is energized. Switch 2|6 is also provided with a normally closed auxiliary contact 2|-6e and normally open auxiliary contacts 2|6f and H69. Connected between one of the main contacts of the switch 2 l3 and one terminal of the motor armature 53a is the energizing winding 2|1a, of an overload relay .2", which is provided with normally closed contacts 2|1b. Mounted adjacent to the slide 56,

which is illustrated in the diagram as a reciprocating bar, and as shown in full lines in its extreme outer position, are the normally closed limit switches 2|8a, 2|9a, 220a, and the normally open limit switches 22la, 222a, and 223a, while suitable abutments 2l8b to 223D are provided on the slide 53 for operating the corresponding limit switches. Mounted adjacent to the gear sector 98 is a normally open limit switch 229, which is closed when the toggle is straightened out. There is also provided a timing relay 230 having an energizing coil 230a, normally open contacts 230b, and a retarding dash- pot 230,0. Mounted on or otherwise coupled to the rotating shaft is a switch 23| having an arm 231a, which is adapted to bridge stationary contacts 23") and 23lc, as the arm is rotated by the shaft.

To control the fuel or other heating medium the system is provided with actuating solenoids 232 which admit heating energy when energized. An indicating lamp 233 is connected in parallel with the solenoids to indicate when they are energized. The solenoids in turn are controlled by a relay 234, which has an energizing winding 234a, and normally open contacts 234b, 2340, and 234d. The switches H3 and 2, are alternately energized by a reversing relay 235, which is provided with an energizing winding 235a, a contact lever 235b, and stationary contacts 235c and 235d. When the coil 2350. is energized it causes the lever 23512 to move from one stationary contact to the other to make circuit therewith. A manually operated reversing valve 235 is provided for controlling the supply of working fluid under pressure to the hydraulic cylinder I01. A pressure regulating valve of any suitable time (not shown) may be inserted in the fluid supply conduit to regulate the pressure of the fluid and thus the thrust applied to the shaft 24.

When it is desired to roll a gear the operator sets the switches 200, 2M, 202 and 203 for automatic operation which closes the contacts 200b, 20lb, .2021), 203b. Thereupon he actuates the hydraulic valve 238 which admits fluid pressure to the cylinder I01 to straighten out the toggle l03|04 and clamp the gear blank W in the machine as has been described heretofore. As the toggle straightens out the gear sector 98 closes the limit switch 229 to connect the bus bar 231, to the line L2. This establishes a circuit from bus bar 231, through contacts 200b, limit switch y me, energizing coil 234a, limit switch 218a, to line Ll, thereby actuating the relay 234 to close the contact 234b. A circuit is thus established from line L2, through the coils 232 and the pilot light 233, through contacts 234b, to line LI, and the coils 232 are energized to admit fuel to the gas burner nozzles H8. It should be mentioned here that the gas valves may be provided with auxiliary means (not shown), which during the idle periods furnish a limited supply of fuel, so as to keep the burned'ignited. Any other arrangement serving the same purpose may be made, such as an ignition coil which is energized in parallel with the coils 232 so as to ignite the gas flame upon opening of the gas valves.

Energization of relay 234 also closes the auxiliary contacts 234d, which are in parallel with the limit switch 22la, the latter being closed in the extreme outward position of the slide block 56, so that the relay 234 remains energized when the limit switch '22Ia' is opened upon the slide traveling inwardly. When the slide reaches its innermost position the limit switch 218a is opened thereupon again deenergizing the relay 234 and cutting off the heating supply.

With the bus bar 231 energized, a circuit is also established from bus bar 231 to contacts 201b, contacts 2l4e, energizing coil 2l3a, through contacts 235d, switch lever 235b, to line Ll, or

alternately through contact 213e, energizing coil 2l4a, contact 2350, switch lever 235b, to line Ll. Thus the forward switch H3 or alternately the reverse switch 214 are energized, depending upon the position of the lever 235b. In the position shown the forward switch 2|3 is energized and it closes its normally open main contacts M311 and H30 and connects themotor 53 for right hand rotation of the machine. Rotation of the machine causes rotation of the switch arm 231a and this periodically establishes a circuit from line L2, through the switch 23l, energizing coil 235a, to line Ll. Each energization of the electromagnet 233a causes the switch arm 23th to oscillate from one to the other stationary contacts 2350 or 235d, to alternately energize the reversing switches 2t3 and-2H. When the reverse switch 2 is energized its main contacts connect the motor 53 to the line for reverse rotation, and the rotation of the motor 53 alternates as long as the switch 23! rotates.

' A circuit is also established from bus bar 231, through contacts 202b, limit switch 2l9a, energizing coil 2l5a, over contacts 2| 1b and 2l8e, to line LI. This energizes the feed motor switch M5 and connects the feed motor 64 to the bus bars LI and L2, by closure of the main contacts M51) and 2I5c. The feed motor thus moves the slide 56 inwardly to feed the die roll into the gear blank to generate the gear teeth. When the slide 56 has reached its innermost position it opens the limit switch 2l3a. thereby deenergizing the winding 2i5a, and the switch 2l5 disconnects the feed motor 64 from the line and the slide comes to a standstill.

Just prior to the moment when the slide reaches the innermost position the limit switch 222a closes, while deenergization of switch 2l5 closes the auxiliary contacts 2 I 5!, so that upon stoppage of the slide I6 by disconnection of the motor 64, a circuit is established from the bus bar 231, through contacts 202b, limit switch 222a, energizing coil 230a, over contacts 2l5f to line Ll. This energizes the timing relay 230, while the slide 56 stands still. During this time the motor 53 continues to rotate the gear and the die roll in one direction or another, dependent upon the position of the switch 233, so that the tool, being in contact with the flnished gear, burnishes the teeth thereof to give it a high surface finish.

.After a lapse of time determined by the adjustment of the dash-pot 2300, the relay 230 closes its normally open contacts 2301). This establishes a circuit from the bus bar 231, through contacts 203b, 230b, limit switches 223a, and 220a, energizing coil 216a, and contacts 2I5g to line Ll, to energize the return motor solenoid switch 2l6, which upon response closes its main contacts to connect the return motor armature 65a to the lines Li and L2, and also energize the brake 33 to release the same. Upon response the relay 216 also closes its auxiliary contacts 2l6f and opens the auxiliary contacts 2l6e. Opening of the auxiliary contacts 2l6e prevents the feed motor switch 2I5 from being energized upon reclosure of limit switch 219a on the return stroke of the slide 56. Closure of auxiliary contacts 216 by-passes the contacts 230b, 223a, so that upon deenergization of the time relay 230 and reopening of the limit switch 223a on the return movement of the slide 56, the solenoid switch2i6 and the return motor 65 remain energized until the slide 56 has returned to its outermost position, in which position the normally closed limit switch 220a is opened todeenergize .the switch 11 216 and stop the return motor 65. When the slide 56 ha again reached the outermost position, the operator may reverse the pressure fluid to the cylinder I01 which acts to move the gear sector 38 to release the gear from the holding jaws and opens the limit switch 223 to deenergize the bus bar 231, so as to cut of! energy from all of the solenoid switches to bring the equipment to rest.

If it is desired to adjust the valve solenoids 232, the operator may operate switch 200 to open the contacts 200?) and close the contacts 200a. He is then able, by closure of the push button switch 204, to energize the relay 234 by a circuit from line L2, over contacts 200a, 204, 209, through energizing coil 234a, and limit switch 2|0a to line Ll. The push button 204 is paralleled by the contacts 234e, so that the coil 234a remains energized when the push button 204 is released. If it is desired to deenergize the relay 234, the push button 203 may be depressed which opens the maintaining circuit of the relay coil 234a.

If it is desired to control the motor 53 manually for rotating the gear and the gear blank independent of the other functions of the machine,

the control switch 20l is operated to open the.

contacts 20Ib and close the contacts 201a. Thereupon the manual push button switch 205 may be depressed which establishes a circuit from line L2, through contacts 20la, 205, M0, 2l4e, coil 2l3a, or alternately contacts 2l3e and coil 2 Ma, through the circuit already traced, to energize either the switche H3 or 2H for connecting the motor 53 to the lines LI, and L2. When the motor 53 rotates the machine it also rotates the switch 23! to actuate the reverser 235 in the manner afore-described. While the slide stands still, the switch 23! is not operating and therefore motor 53 will always operate in the same direction when energized. If under these conditions it is desired to reverse rotation 01 the motor 53, the operator actuates the push button switch 206 which energizes the coil 235a to commutate the switch 235 and the connections of motor 53 are reversed. It is also to be noted that operation of the motor 53 ceases upon opening of switch 2 I0.

If it is desired to move the slide 55 independently in one direction or the other, the switch 202 is operated to open the contacts 202b, and close the contacts 202a, and also the switch 203 is operated to open the contacts 203D and close the contacts 203a. If then the operator wishes to feed the slide 56 inwardly, he pushes the button 201, thereby establishing a circuit from line L2, through cont- acts 202a, 201, 2| I, limit switch 2 I 3a, through the energizing coil 2 I 5a and over the circuit already traced. This energizes the switch 215 to connect the said motor 04 to the line to move the slide inwardly. Response of switch 2|5 closes the auxiliary contact 2I5e, which parallels the switch 201, so that the feed motor continues to operate upon release of the push button 201, until in the innermost position the limit switch 2l0a, opens to disconnect the feed motor from the line. If the operator wishes to stop the slide 55 before it reaches the innermost position he may push the push button switch 2| I, thereby deenergizing the switch 215 which opens the maintaining contact 2l5e and the feed motor comes to rest. If the operator wishes to actuate the return motor he pushes the button 200. This closes a circuit from line L2, through contacts 2030., 200, M2, limit switch contact 220, through the coil' 2|5a, contact 2l5g, to line Ll. Thus the switch 2 I8 is energized to energize the return motor 65. Energization of relay 2l8 also closes contacts 2l6'g to maintain the switch 2 is energized upon release of the push button 208, and until the limit switch 220a opens the circuit upon the slide 56 returning to the retracted position. If in any other position the operator wishes to stop the return movement of the slide 50, he pushes the push button 2l2, which momentarily deenergizes the switch H6 and stops the equipment.

It will thus be seen that the system provides for independent manual control of each individual movement of the machine and for full automatic control to operate the machine through a complete cycle of forming a gear. The control system described herein has been chosen by wayof example. It may be modified in many ways without departing from the invention as will be obvious to one skilled in the art.

It will of course be understood that suitable automatic accelerating means may be used in the armature circuits of the motors 53, 64, and 65, where the size- 01' the motor requires separate means to limit the inrush current upon energization of the motor armature. It will further be apparent that the speed of the different motors may be adjusted by adjusting their field regulating resistors and it is further possible to provide separate field regulators for the field winding 53b of the motor 53, so that the field regulators for the forward and reverse direction may be adjusted separately and the motor may be operated at different speeds in the two directions. Where desirable induction motors or any other suitable type of motors may be employed for the machine, as is obvious to one skilled in the art.

What I claim as new and desire to secure by Letters Patent is:

1. In an automatic gear rolling machine, in combination, a base, two shafts rotatably mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a workpiece therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a slide supported on said base for resaid base parallel to the direction of motion of said slide, a reversible motor, fixed speed ratio driving connections between said motor, said drive shaft, said arbor, and the other of said first mentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft connected to said slide to move it in opposite directions, an input shaft, and a rotatable casing geared to said output shaft, 3, feed motor connected to said input shaft to effect rotation of said casing in one direction and a return motor connected to said casing to effect rotation thereof in the opposite direction, automatic means responsive to operation of said hydraulic means for controlling energization of said motors, including automatic means for periodically reversing the energization of said reversible motor, automatic means responsive to the position of said slide to control said automatic reversing means and to alternately energize said feed motor and said return motor and including time delay means arranged to delay the energization of said return motor, and manually operated selector means to provide for individual manual energization of said motors independent of the operation of said hydraulic means.

2. In 'an automatic gear rolling machine, in combination. a base, two shafts rotatably mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a workpiece therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a slide supported on said base for reciprocation perpendicular to the axis of said shafts, an arbor rotatably mounted on said slide in parallel with said shafts and adapted to receive a toothed die, a drive shaft mounted on said base parallel to the direction of motion of said slide, a reversible motor, fixed speed ratio driving connections between said motor, said drive shaft, said arbor, and the other of said first mentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft connected to said slide to move it in opposite directions, an input shaft, and a, rotatable casing geared to said output shaft, 9, feed motor connected to said input shaft to effect rotation of said casing in one direction and a return motor connected to said owing to eifect rotation thereof in the opposite direction, automatic means responsive to operation of said hydraulic means for controlling energization of said motors, including automatic means for periodically reversing the energization of said reversible motor, automatic means responsive to the position of said slide to control said automatic reversing means and to alternately energize said feed motor and said return motor, and manually operated selector means to provide for individual manual energization of said motors independent of the operation of said hydraulic means.

3. In an automatic gear rolling machine, in combination, a base, two shafts rotatabiy mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a workpiece therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a slide supported on said base for reciprocation perpendicular to the axis of said shafts, an arbor rotatably mounted on said slide in parallel with said shafts and adapted to receive a toothed die, a drive shaft mounted on said base parallel to the direction of motion of said slide, a. reversible motor, fixed speed ratio driving connections between said motor, said drive shaft, said arbor, and the other of said first mentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft connected to said slide to move it in opposite directions, an input shaft, and a rotatable casing geared to said output shaft, 9. feed motor connected to said input shaft to effect rotation of said casing in one direction and a return motor connected to said casing to effect rotation thereof in the opposite direction, automatic means responsive to operation of said hydraulic means for controlling energization' of said motors, including automatic means for periodically reversing the energization of said reversible motor, and automatic means responsive to the position of said slide to control said automatic reversing means and to alternately energize said feed motor and said return motor.

4. In a gear rolling machine, a reciprocable slide, a die support rotatably mounted on said slide with its axis transversely to the movement of said slide, a work holder including two axially aligned rotatable work supporting shafts having ment with said clamping 14 A clamping means at their adjacent ends, reversible actuating means connected to one of said shafts for axiallymoving the same relative to the other and clamping a workpiece into driving engagemeans, a reversible motor connected to said other shaft and to said die support for rotating said other shaft and said die support at fixed speed ratios relative to each other, a planetary gear set having a rotatable casing connected to said slide for moving the same transversely in opposite directions in accordance with the direction of rotation of said casing, a motor connected to an input shaft of said differential and adapted when energized to rotate said casing to move said slide and said die support toward said work holder, a second motor connected to another input shaft of said planetary gear set and adapted to rotate said casing in the opposite direction, for moving said slide away from said work holder, means for heating said workpiece in situ, and adjustable means for selec-v tively effecting operation of any of said motor and of said heating means in accordance with a predetermined adjustable cycle.

5. In a gear rolling machine, a reciprocable slide, a. die support rotatabiy mounted on said slide with its axis transversely to the movement of said slide, a work holder including two axially aligned rotatable work supporting shafts having clamping means at their adjacent ends, reversible means connected to one of said shafts for axially moving the same relative to the other and clamping a workpiece into driving engagement with said clamping means and to regulate the clamping pressure, a reversible motor connected to said other shaft and to said die support for rotating said other shaft and said die support at fixed speed ratios relative to each other, a planetary gear set having a rotatable casing connected to said slide for moving the same transversely in opposite directions in accordance with the direction of rotation of said casing, a motor connected to an input shaft of said planetary gear set and adapted when energized to rotate said housing to move said slide and said die support toward said work holder, a second motor connected to another input shaft of said planetary gear set and adapted to rotate said casing in the opposite direction, for moving said slide away from said blank, means for heating said workpiece in situ, and adjustable means for selectively effecting operation of any of said motors and of said heating means in accordance with a predetermined adjustable cycle.

6. In an automatic gear rolling machine, in combination, a base, two shafts rotatabiy mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a workpiece therebetweem means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a slide supported on said base for reciprocation perpendicular to the axis of said shafts, an arbor rotatably mounted on said slide in parallel with said shafts and adapted to receive a toothed die, a chamber surrounding each of said shafts in proximity of its respective jaw, a chamber surrounding said arbor adjacent to its die receiving end, said chambers being adapted to receive a cooling fluid for cooling said shafts and said arbor, a drive shaft mounted on said base parallel to the direction of motion of said slide, fixed speed ratio driving connections between said drive shaft, said arbor, and the other of said first mentioned shafts, a planetary gear set supported on said base and comprising an input shaft, a reversible rotatable casing and a reversible output shaft connected to said slide to move it in one direction upon rotation of said input shaft, and in the other direction upon rotation of said casing while said input shaft is at rest.

7. In an automatic gearrolling machine, in combination, a base, two shafts rotatably mounted in axial alignment on said base and provided at their adjacent ends with cooperating Jaws for clamping a. workpiece therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a, slide supported on said base for reciprocation perpendicular to the axis of said shafts, and provided with a screw thread, an arbor rotatably mounted on said slide in parallel with said shafts and adapted to receive a toothed die, a drive shaft mounted on said base parallel to the direction of motion of said slide, a reversible motor, fixed speed ratio driving connections between said motor, said drive shaft, said arbor, and the other of said firstrmentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft provided with a threaded end engaging said screw thread of said slide to move it in opposite directions, an input shaft,

and a rotatable casing geared to said output shaft, 9, feed motor connected to said input shaft to effect rotation of said casing in one direction and a return motor connected to said casing to effect rotation thereof in opposite directions, automatic means responsive to operation of said hydraulic means for controlling energization of said motors, including automatic means for periodically reversing the energization of said reversible motor, and automatic means responsive to theposition of said slide to control said automatic reversing means and to alternately energize said feed motor and said'return motor.

8. In an automatic gear rolling machine, in combination, a base, two shafts rotatably mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a, workpiece therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a, slide supported on said base for reciprocation perpendicular to the axis of said shafts, and provided with a screw thread, an arbor rotatably 16 nately energize said feed motor and said return motor.

9. In an automatic gear rolling machine, in combination, a base, two shafts rotatably mounted in axial alignment on said base and provided at their adjacent ends with cooperating jaws for clamping a, workpiec therebetween, means including fluid pressure means arranged for axially moving one of said shafts relative to the other, a slide supported on said base for reciprocation perpendicular to the axis of said shafts, and provided with a screw thread, an arbor rotatably mounted on said slide in parallel with said shafts and adapted to receive a toothed die, a drive shaft mounted on said base parallel to the direction of motion of said slide, a reversible motor,flxed speed ratio driving connections between said mounted on said slide in parallel with said shafts mounted on said base parallel to the direction of motion of said slide, a reversible motor, fixed speed ratio driving connections between said motor, said drive shaft, said arbor and the other of said first mentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft provided with a threaded end engaging said screw thread of said slide to move it in opposite directions, the axis of said output shafts, said arbor, and said first named two shafts being in a, common plane, an input shaft, an a rotatable casing geared to said output shaft, a feed motor connected to said input shaft to effect rotation of said casing in one dimotor, said drive shaft, said arbor, and theo he! of said first mentioned shafts, a planetary gear set supported on said base and comprising a reversible output shaft provided with a threaded end engaging said screw thread of said slide to move it in opposite directions, an input shaft, and a rotatable casing geared to said output shaft, a thrust bearing concentric with said output shaft and arranged to receive the reaction of the forces exerted upon said slide to move it in opposite directions, a feed motor connected to said input shaft to effect rotation of said casing in on direction and a return motor connected to said casing to effect rotation thereof in the opposite direction, automatic means responsive to operation of said hydraulic means for controlling energization of said motors, including automatic means for periodically reversing the energization of said reversible motor, and automatic means responsive to the position of said slide to control said automatic reversing means and to alternately energize said feed motor and said return motor.

10. In an automatic gear rolling machine, in combination, a base, a shaft rotatably mounted on said base, hydraulic means for moving a workpiece into driving engagement with said shaft, a slide supported on said base for reciprocation perpendicular to the axis of said shaft, an arbor rotatably mounted on said slide in parallel with said shaft and adapted to receive a toothed die, a reversible motor, fixed speed ratio driving connections between said motor, said arbor, and said first mentioned shaft, a planetary gear set supported on said base and comprising a reversible output shaft connected to said slide to move it in opposite directions, an input shaft, and a rotatable casing geared to said output shaft, a. feed motor connected to said input shaft to effect rotation of said casing in one direction and a return motor connected to said casing to effect rotation thereof in the opposite direction, automatic means responsive to operation of said hydraulic means for controlling energization of said motors, in cluding automatic means for periodically reversing the energization of said reversible motor, automatic means responsive to the position of said slide to control said automatic reversing means and to alternately energize said feed motor and said return motor, and manually operated selector means to provide for individual manual energization of said motors independent of the operation of said hydraulic means.

11. In an automatic gear rolling machine, the combination in accordance with claim 10, with means for heating the workpiece in situ, automatic control means responsive to operation of said hydraulic means and said feed motor energizing means for operating said heating means,

and manual selector means to provide for alternate manual control of said heating means in addition to said hydraulic means and said feed motor energizing control means.

12. In a gear rolling machine of the character described, manually controlled hydraulic means for selectively clamping and releasing a gear blank, electromagnetic means responsive to the clamping action of said hydraulic means and in cluding cycling means for successively eflecting, initiation of heating the gear blank, rotating the gear blank and tool alternately in opposite directions, feeding the tool into the work, terminating the heating and the feeding of the tool after a I given travel of the latter, terminating rotation of the blank and tool and withdrawing the latter to its initial position, and manual means for REFERENCES CITED I The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,459,767 Hildebrand June 26, 1923 1,460,528 Anderson July 3, 1923

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