US2360800A - Hobbing machine - Google Patents

Description

Oct. 17, 1944. o. E. STAPLES 2,360,800

HOBBING MACHINE Filed Jail. 1, 1943 4 Sheets-Sheet 1 I II II HI I I ll I Y ll INV ENT(\)R.

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O. E. STAPLES HOBBING MACHINE Filed Jan. 1, 1943 -Oct. 17, 1944. o. E. STAPLES HOBBING MACHINE Filed Jan. 1, 1945 4 Sheets-Sheet 4 I Patented Oct. 17, 1944 UNITED STATES PATENT OFFICE HOBBING MACHINE Otis E. Staples, Euclid, hio, assignor to The Cleveland Hobbing Machine Company, Euclid, Ohio, a corporation of Ohio v Application January 1, 1943, Serial No. 470,973

' 4 Claims.- (Cl. 90-4) The present invention relates to hobbing machines of the general type disclosed in my copending application Serial No. 410,744, filed September 13, 1941, now U. S. Patent No. 2,307- 428, issued Januaryfi, 1943.

The principal object of the invention is the provision of a novel improved hob'bing machine of the type referred to, in which the vertical feed movement of the work Head is or can be,

automatically interrupted prior to the time the rotation of the tool and work spindle is automatically stopped, thus making it possible to cut splines of equal length, which is impossible with the machine of the aforesaid application.

Further objects and advantages of the invention will be apparent to those skilled in the art to which the invention relates from the following description of the, preferred embodiment described with reference to the accompanying.

drawings forming a part of this specificationand in which:

Fig. 1 is a perspective view of ahobbing machine embodying the present invention;

Fig. 2 is a horizontal section with portionsbroken away and portions in elevation through the work head of the machine approximately on the l 'ine.2:- 2 of Fig. 3;

Fig. 3 is a section approximately on the line 3-3 of Fig. 2 with portions in elevation;v

Fig. 4 is anenlarged front elevation of a part of the machine shown in Fig. 1;'

Fig. 5 is a section with portions in elevationapproximately on the line 5-5 of Fig. 4; and

Fig. 6 isa-schematic wiring diagram of the machine. T

For the most part the machine of the preferred embodiment herein described and illustrated is similar in construction to the machine disclosed in my aforesaid Patent No. 2,307,428,, and therefore will not be-herein shown. and described in detail. Reference i simade to said application,

for a complete disclosure of the parts of the machine not herein shown and described in detail.

Generally speaking, the machine shown comprises -a base A;ha ving a vertical column B fixed thereto, a work head C slidably supported on vertically spaced pairs of vertical ways 8' andv 9 on the column. B, and a tool or hob head D.

adjustably supported on horizontal ways ID intermediate the ways 8 and 9. The tool and work spindles are geared together and driven from'a reversible electric motor H (see wiring diagram) located within the column B and hereinafter referred to as the cut motor. A relative feed .movement between the spindles is effected cooperates, is provided for rapidly elevating or lowering the Work head,.C, as the case may be,

to quickly bring the work blank -W up to the hob H at the beginning of the cycle of operations and to return the work .head'to its starting position after the work has been cut and removed. The traverse motor is also housed. withinth column B. In the embodiment shown,

the work W is adapted to be supported between a suitable chuck I5 fixed to the upper end of the work spindle I6 and a center I! carried by a tailstock 8 slidably, supported on vertical ways l9 on the. work head C.

The tool and work spindles are geared to'- gether and operatively connected to the cut mo:

tor by gearing including ahorizontal shaft 20.

' rotatively supported in the work head C and projecting forwardly through a partition 2| in the work head C and into a gear box. or compartment, designated generally by the reference character22. The shaft 20 isoperatively connected to a horizontal shaft 23 through the me- 'dium ofwork spindle drive change gears E, the driving and driven gears 24 and 25 of which are keyed to the ends of the shafts 20 and 23, respectively. The shaft 23 is rotatably supported in an adjustable cradle, 26 and is provided with a worm .2'| continuously in mesh with a worm wheel 28 keyed to the work spindle I6.

To effect the relative feed movement between the tool and work the work head C is moved upwardly during the cutting operation in timed relation to the rotationof the tooland work spindles by the lead screw |2 previously referred to. The ,lead screw is adapted to be rotated from the work spindle driveby a worm wheel 30 keyed to the upper end thereof, which worm wheel is continuously in mesh with a worm 1 3| rotatably supported on a shaft 32 andv fixed to one element 33 of a toothed clutch, designated generally as F, the other orldriving element 34 of which is slidably splined to the shaft 32. The shaft 32, like the shafts 20 and 23, projects through the partition 2| and into the. gearbox 22 within which it is operatively connected to the shaft 23 by the feed'change gears G, the driv- -ing and driven gears and 38, respectively, of

which are fixed to the shafts Y23 and 32, respectively. For the purposes of permitting the use of various change gears, idlers, etc., in the work spindle drive change gears E and the feed change gears G, suitable spiders or gear supporting members ,31 and 38 are provided.

The clutch F is engaged and disengaged to connect and disconnect the feed lead screw 12 to and from the drive for the tool and work spindles by shifting or slidin the clutch element 34 to the left or right, respectively, as viewed in Fig. 2. The purpose of the clutch F will be hereinafter apparent from the resum of the *operation of the machine. The clutch element 34 is provided with an external cylindrical groove within which the lower end of a yoke member 48 engages. The yoke member 48 is pivotally connected for rotation about a vertical axis to the projecting end of a lever 4| fixed to the upper end ofa vertical shaft 42, the lower end of which projects through the work head frame and has fixedthereto a lever 43. s

The lever 43 is operatively connected to a slidable member or rod 44 by a link 45,the length of which can. be adjusted, and opposite'ends of which link are bifurcated and pivotally connected to the lever 43 and the rod 44 by pivot 'pins 48 and", respectively. The rod '44 is slidablysupported in a horizontal cylindrical aperture 48 in a housing or member 48 fixed to the work head C by screws 50 adjacent the left-hand bottom way 8,'and is continuously urged to the right, as viewed in Fig. 5, by a compression spring 5| interposed between a shoulder 52 on the rod 44 formed by the reduced right-hand endthereof and a tubular member 53 threaded into the right-hand end of the aperture 48. The reduced end of the rod 44 extends throughthe central aperture of the tubular member 53. The rod 44 is adapted to be shifted towards the right, as viewed in Fig. 5, by a hand lever 54 fixed to the left-hand end of a short shaft 55 rotatably supported 51 fixed to the member 49; The opposite end of the shaft 55 carries a lever 58 also fixed thereto, the lower forked end of which lever is connected to the rear end of the'r'od 44 by a pin 59.

When the rod 44 is moved -to the right as viewed in Fig. 5 an amount sufficient to engage the clutch F, it is adapted to be held in that position by a latch or bolt 60 slidably supported in a vertical aperture 6|, the upper end of which bolt is adapted to engage in a suitable aperture 82 in the rod 44. Thefbolt 60 is continuously urged in an upwar direction by a compression spring 63 interposed etween the lower end of the bolt proper and the upper end of a member 64 threaded into thelower end of the aperture 6|. The member 64 has a central aperture through which a rod 65 connected to the lower end of the bolt proper projects. The lower end of the rod 85 is bifurcated and pivotally connected to a pivoted bar 68 by a pin 61. The. front end of the bar-56 is pivotally supported on a bolt '59 fixed in a downwardly projecting member 68- while theother end thereof projects towards the rear of the machine where it is adapted to -be engaged by a stop 10 adjustable along a rod'o'r barli fixed to the column B in a suitable manner, The construction is such that when the rear end of the bar 66 engagesthe stop 10- incident to the vertical movement of the work head C the bar 66 is moved about its pivot 8,3 and the upper in a boss 58 on the upper end of a bracket end of the bolt 60' withdrawn from the aperture 62 whereupon the rod 44 moves to its left-hand position under the influence of the spring 5 I thus disengaging the clutch F.

After a work blank W is positioned in the work head, the machine is started by pushing a start push button switch 83 located on a switch panel 84 mounted on the side of the machine,

whereupon the traverse motor l3 operates to ro-. tate the nut with which the lead screw 12 engages at a high rate of speed and in such a direction that thework is rapidly moved toward the hob H. Just prior to the time the work W engages the hob H a switch 85 located on the left-hand side of the column Bis actuated by an adjustable stop 86 carried by the work head C; stopping the traverse motor l3 and starting the cut motor H.

In the event the snap switch 9! located on the switch panel 84 is opened the up and down limits of movement of the work head C are automatically controlled by an electric switch 8'! actuated by adjustable stops 88 and 89 also carried by the work head C. The stop 88 controls the downward limit of movement and the stop 89 the upward limit of movement of the work head C.

In the event the snap switch 9| is closed, the cut motor I I is not stopped upon actuation of the limit switch 81 by the stop 89 but is manually controlled bythe stop switch 92 which is actuated by the operator after the feed movement has been interrupted by disengagement of the clutch F. According to the provisions of the present invention, the work makes at least one revolution after the clutch F has been disengaged so that the splines, etc., are all the same length.

After the blank has been cut and removed, the work head C is returned to its starting position by again depressin the start push button'switch 83. For safety,-a normally closed travel limit switch is provided, see wiring diagram. The

limit switch 98 is located on the right-hand side of the column B and for that reason is not shown in Fig. 1 of the drawings, but is so mounted and adapted to be opened by a fixed stop carriedby the work head 0 that the work head C cannot be raised high enoughv to damagethe machine even though the other switches fail.

The particular machine shown herein can be operated either in exactly-the same manner as the machine disclosed in my aforesaid application Serial No. 410,744, by opening the snap switch 8 I, in which event the clutch F does not disen age as the stop 89 is set to actuate the switch 81 before the lever 68 engages thestop 18. The direction in which the cycle of operations is effected is controlled by drum controllers I and J also mounted on the switch panel 84. The drum controller I has two positions, designated up and down, respectively. When the drum tontroller I is set in the up position, the circuits to the switches 85, 81, etc., are connected to execute the cycle of operations wherein the work head C moves in an upward direction to eflect the feed, and vice versa. The drum controller J has two positions, designated "forward and reverse, respectively. When the controller is set in the forward position, the direction of rotation of the hob spindle is such that the hob'moves down in front, that is in a clockwise direction as viewed in Fig. 1, and vice versa., Since the feed can be effected in either direction of movement of the work head C and since the cut motor which drives'the hob can be reversed, it will be apparent that either .clim

ed in either direction merely by setting the drum controllers I'and J in the selected positions and either inserting or removing an idler gear in the spindle drive change gears E or the feed change gears G, orin other words, by so selecting the change gears that the feed is in the proper direction. v

The cut and traverse motors are preferably of the reversible three-phase alternating current type and are adapted to be connected to and disconnected from the power lines 95, 96 and 91 by Operation In the embodiment shown, the clutch F functions only when the cycle of operations is such that the feed is effected by an upward movement of the work head C. Since this cycle of operations is the only one which is materially different from that disclosed in the aforesaid application, it alonewill be described in detail. With the drum controller I set in up position, the drum I hobbing or conventional hobbing can be efiectaddition to closing the main power contacts I50, I5I; I52, I53; I54, I55; which connect the motor I3 to the power lines, closes auxiliary contacts I56, I51, establishing a holding circuit for maintaining the solenoid I31 energized even though the relay II1 may subsequently be deenergized. When the stop push button switch 83 is released the circuit for relay H1 is opened upon the opening of contacts II I and H2 but is immediately reestablished through contacts I01, I06, the closing of which establishes a circuit from wire II 4 through auxiliary contacts I56, I51, wire I36, contacts I01, I08, wire II5, operating solenoid II6, etc. to line 96. The reclosing of contacts I24, I25 which are in parallel circuit with contacts I56, I51 maintains the operating solenoid I I6 of relay II1 energized even though contacts I56, I51 sub-- sequently open, as hereinafter mentioned.

' travel limit switch-'90, wire II3, stop push button.

controller J set' in forward" position, and the change gears as shown in the drawings, the machine is arranged to go through its cycle of op-.

erations wherein the feed is effected by an upward movement of the work head C, with the hob rotating clockwise as viewed in Fig. 1; in other 'tacts I09, IIO; III, II2 The closing of the contacts III and H2 establishes a circuit from the line 91 through the overtravel limit switch 90.

wire I I3,'normally closed stop push button switch 92, wire II4, contacts III, II2,'wire II5, operating solenoid I I6 of relay I I1, wire 8,. contacts 8, I20 of drum controller I, wire I 2I contacts I22, I23 of switch 81, to line 96, energizing'the solenoid I I6 of relay II1. Energization of the operating solenoid II6 of relay II1 closes the nor- The travel motor I3 continues to operate raising the work head C until just prior to the engagement of the work W with the hob H, at which time the stop 86 on the work head C actuates the switch 85 opening the previously closed con- The closing of contacts I60, I6I establishes a" circuit for. the operating solenoid I62 of motor controller-.93 from the line 91, through the overcontacts I60, I6I of limit switch 85, wire II8,

contacts II9, I20 of drum controller I, wire 'I2I, contacts I22, I23 of limit'switch 81rto line 96.

Energization of the operating, solenoid I62 of motor controller 93 closes the main power contacts I10, I1I'; I12, I13; I14, I15 and connects the cut motor II to the power lines 95, 96 and mally open contacts I24, I255 I26, I21; I28, I29

and opens the normally closed contacts I30, I3I thereof. v

, The closing of contacts I24,. I25 establishes a circuit from the line 91 through the overtravel limit switch 90, wire I I3, stop push button switch 92, wire II4, contacts I24, I25, wire I36, operating solenoid I31 of motor controller 94, wire I38, contacts I 39, I40 of drum controller 1, wire I4I, contacts H9, I20 of drum controller 1-, wire I2I, contacts I22, I23 of limit switch 81 to line 96, energizing the solenoid I31 and connecting the motor I3 to the power lines 95, 96 and 91, in such a man-- ner that the motor operates in a direction tor'aise the work head C, The wires I 03 and I04 previously referred to are connected to the motor I3 by contacts-I44, I45; I46; I41 of drum controller I and wires I48 and I49.

Energization of the operating solenoid I31, in

opening contacts I24,-I25; I26," I21; I28, I29 01'.

9.1 through the drum controller J byv means of I contacts I16, I11; I18, I19 and wires I80, I8I.

The work head C continues to rise under' the operation of the cut motor II at a feed rate and as it approaches its upper limit 01 travel, the stop 89 actuates the limit switch 81 to open the previously closed contacts I22, I23 and close thepreviously open contacts I82 and I83. The opening 01 contacts I22, I23 of limit switch 81 opens the circuit for the operating solenoid I62 previously referred to. However, the solenoid is maintained energized by a circuit through contacts I28, I29 of relay II1, wire 114, contacts I58, I 59 of limit switch 85, wire I85, snap switch 9|, which is now closed, to line 96. The operating solenoid H6 01 the feedstops. However, the cut motor continues to operate, rotating. the tool and work spindles in predetermined relation. After the work spindle has made at least onecomplete-rotation, the operator, pushes the stop push button 92, deenergizing the solenoid II6 of relay II1,

said relaythe contacts I28, I29 which in turn open the circuit to the operating solenoid I62,

disconnecting the cut motor II from the power lines 95, 98 and 91.

In the event the snap switch 9| isopen, which would be the case if the machine was operated in accordance with the cycle disclosed in my aforesaid application, the cut motor would stop upon actuation of the limit switch 81 by the stop 89 since the opening of the contacts I22, I23 thereof would break not only the circuit to the operatingsolenoid IIB of relay II1, but also the circuit to the. operating solenoid I82 of motor controller 93.

The finished work blank is now removed from.

of relay I.I1, wire I81, operating solenoid I88 of motor controller 94, wire I89, contacts I90, I9I

of drum controller 1, wire I92, contacts I 82, I83 of switch" 81 to line 96.

Energizati'on of the solenoid I88 closes the main contacts I93, I94, I95, I88, I91, I98 associated therewith, connecting the rapid traverse or travel motor I3 to the power lines in such a manner that it operates in the reverse direction, that is, in a direction to lower the work head C. Simultaneously with the closing of the contacts which connect the motor I3 with the power lines, auxiliary contacts 200, 20I are closed, establishing a holding circuit for the solenoid I88 after thestart push button switch 83 is released. This holding circuit is fromthe line 91 through the 'overtravel limit switch 90, wire II3, stop push button switch 92, wire II4, contacts 200, 20l, wire I81, solenoid I88, wire I89, contacts I90, I9I of drum controller 1, wire I92, contacts I82, I83 of switch 81 to line 96.

As the work head C drops; the adjustable stop 86 thereon returns the switch 85 to its original position as the stop passes the switch. This reopens the contactsI58, I59; I80, IGI and closes the contacts I42, I43, thus again setting up. the circuit with respect to the'cut motor I I which existed at the beginning of the cycle of operations. The work head C continues to move down until the switch 81 is tripped by the adjustable stop 88 carried by the, work head C. This reopens the contacts I82, I88,stopping the rapid traverse or travel motor I3 and recloses the contacts I22, I23, returning the circuit to the rapid traverse or cut motor I3 to its original condition. After a new work blank is inserted in the work head C, the cycle of operations of the machine can be repeated by again pressing the start push button switch 83.

From the foregoing description of the preferred embodiment of the invention, it will be apparent that the objects heretofore enumerated and others have been accomplished and that a new and improved machine of the character referred to has been provided. While the preferred embodiment of the invention has been described with cnsiderable detail, it is to be understood that theinvention is not limited to the particular -constructionl shown. For example, in the embodiment described the clutch F functions'only when the feed is eflected by a vertical movement of the work head. However, the machine shown could readily be modified so that the clutch F would function in either direction and irrespective of whether the cutting operation was conventiona or climb. It is my intention to hereby cover all adaptations, modifications and uses of the invention herein disclosed which come within the practice of those skilled in the art to which the invention relates.

Having thus described my invention, I claim:

1. A hobbing machine of the character described comprising: a frame; a work spindle; means for rotatably supporting said work spindle; a hob or tool spindle; means for rotatably supporting said hob or tool spindle; a lead screw and a cooperating nut for producing relative move ment between said work spindle and said tool.

spindle; a first means for rotating said spindles and for producing relative rotation between said lead screw and said nut to efiect a relative movement between said spindles at a feed rate; a second means for producing relative rotation between said lead screw and said nut in opposite directions to effect a relative movement between said spindles at a rapid traverse rate; means for effecting the operation of said second means whereupon relative movement between saidspindles is produced in one direction at a rapid traverse rate; means for automatically initiating the operation of said first means and discontinuing the operation of said second means upon said spindles reaching a predetermined-relative position whereupon the relative movement between said spindles is continued but at a feed rate;

- means for automatically discontinuing the relative rotation between said lead screw and nut upon i said spindles reaching a second predetermined relative position without discontinuing the rotation of said spindles; means for discontinuing,

the operation of said first means after a, predetermined period during which the work spindle makes at least one completerevolution; means for effecting or initiating the operation of said second means but in such a manner that it operates in the reverse direction whereupon relative movement between said spindles is produced in the opposite direction at a rapid traverse rate; and means for automatically discontinuing the operation of said second means upon said spindles reaching their starting or initial relative position.

2. A hobbing machine of the character described comprising: a frame; a, work spindle; means for rotatably supporting said work spindle; a hob or tool spindle; means for rotatably supporting said hob or tool spindle; a lead screw and a cooperating nut for producing relative movement between said spindles; an electric motor for rotating said spindles and for producing relative rotation between said lead screw and said nut to effect a relative movement between said spindles at a feed. rate; a reversible electric motor for producing relative rotation between said lead screw and said nut to efiect a relative movement between said spindles at a rapid traverse rate; means for operafively connecting the second mentioned electric motor to a source of power whereupon relative movement between said spindles is produced in one direction at a rapid traverse rate; means for automaticallyconn'ecting the first mentioned motor to the source of power and disconnecting the second men'- tioned motor from the source of power upon said spindles reaching a predetermined relative posi-' means for automatically interrupting the drive ment between said-spindles is produced in the.

opposite direction at a rapid traverse rate; and

- means for automatically disconn'ectingsaid sec ond mentioned motor from the source 01 power upon said spindles reaching their starting or initial relative position. l

- 3. A hobbing machine of the character de-- scribed comprising: a frame; a vertical work spindle; means for rotatably supporting said work spindle; a hob or tool spindle, means for rotatably supporting said hob or tool spindle; alead screw and a cooperating nut for producing relative movement between said spindles, an electric motor for rotating said spindles and for producing relative rotation between said lead screw and said nut to efiecta relative movement between said spindles at a feed rate in a vertical direction; a reversible electric motor for producing relative rotation between said lead screw and said nut to effect a relative movement between said spindles at a rapid traverse rate; means for opreversible motor from the source of power upon said spindles reaching a predetermined relative position whereupon the relative movement be- ..tween said spindles is continued but at a feed rate; means for automatically interrupting the drive between said first mentioned electric motor and said lead screw upon said spindles reaching a second predetermined relative position; means for disconnecting the first mentionedmotor from the connecting said reversible motor to the source of power but in such a manner that it operates inthe reverse direction whereupon relative movement between said spindles is produced in the opposite direction at a rapid traverse rate; and means for automatically disconnecting said second mentioned motor from the source of power upon said spindles reaching their starting initial relative position.

4. A hobbing machine of the character described comprising: a frame; a work head slidably supported for movement along said frame; a vertical work spindle rotatably supported by said work head, a hob or tool spindle rotatably supported by said frame; a lead screw and a cooperating nut for moving said work head relative to said tool spindle; an electric motor for rotating said spindles and for producing relative rotation between said lead screw and saidnut to move said work head at a feed rate; a reversible electric motor for producing relative rotation between said lead screw and said nut in opposite directions to move said work head at a rapid traverse rate; means for operatively connecting the second mentioned electric motor to a source of'power whereupon said work head is moved in one direction at a rapid traverse rate; means for automatically connecting the first mentioned motor to the source of power and disconnecting the second mentioned motor from the source of power upon said work head reaching a predetermined position whereupon the movement of the work head continues but at a feed rate; means for automatically interrupting the drive between said. first mentioned electric motor and said lead screw upon said spindle reaching a second predetermined relative position; means for disconnecting the first mentioned motor from the source of power after the lapse of a predetermined period within a which said work spindle makes at least one complete revolution; means for connecting the second mentioned motor to the source of power but in such a manner that it operates in the reverse di- -rection whereupon the work head is moved in 5 the opposite direction at a rapid traverse rate;

source of power after the lapse of a predetermined period within which said work spindle and means for automatically disconnecting said second mentioned motor from the source of power upon said work head reaching its starting on initial position.

OTIS E. STAPLES.

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