US3218932A

US3218932A - Automatic feeding apparatus of the cutter saddle in gear shaper

Info

Publication number: US3218932A
Application number: US151716A
Authority: US
Inventors: Kondo Risaku
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-11-07
Filing date: 1961-11-13
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23
Also published as: GB1004881A

Description

Nov. 23, 1965 RlSAKU KONDO 3,218,932

AUTOMATIC FEEDING APPARATUS OF THE CUTTER SADDLE IN GEAR SHAPER INV EN TOR Risa/Va ffomda BY J ATTORNEY Nov. 23, 1965 RlSAKu oN o 3,218,932

AUTOMATIC FEEDING APPARATUS OF THE CUTTER SADDLE IN GEAR SHAPER Filed Nov. 13. 1961 2 Sheets-Sheet 2 4 III INVENTOR Ez'Ja/Z'u ffcwdo ATTORNEY United States Patent 3,218,932 AUTOMATIC FEEDING APPARATUS OF THE CUTTER SADDLE IN GEAR SHAPER Risaku Kondo, 142 Z-chome, Kosugi-goten-machi, Kawasaki, Japan Filed Nov. 13, 1961, Ser. No. 151,716 1 Claim. (Cl. 907) The present invention relates to automatic feeding ap paratus of the cutter saddle in a gear shaper in which said saddle is moved by oil hydraulic pressure quickly at the preliminary stroke of the cutter approaching the work and also at the retire stroke withdrawing the cutter from the work when the cutting has been completed.

Intermediate of the preliminary stroke and the retire stroke the cutter saddle is made to do feeding motion during cutting action with positive drive by such mechanism as toothed gear, cam, etc., the interchange between such different modes of transmission being accomplished by limit switches and their individual actuating means.

The principal object of my invention is to obtain a thoroughly automatic apparatus which may be substituted for hand working, upon which the displacement of the cam operating the cutter saddle had been heretofore relied upon, consequently to gain a general advantage produced by the increase of working efiiciency.

Another object of my invention is to obtain an eifective apparatus in which the idle time of the working is substantially saved at the preliminary or approach stroke, in which the saddle brings the cutter to the cutting position; and at the terminal or retire stroke, in which the saddle withdraws the cutter from the work to the retired position for changing to new uncut work. It is not required that the saddle move precisely during such time saving preliminary and terminal strokes and therefore fluid pressure changes may cause such movement; but it is required that precision and stability are secured during the intermediate cutting stroke and this latter requirement is obtained by my positive cutter drive. Therefore, both requirements are within the objects of my invention.

These and more detailed and specific objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in which:

FIG. 1 is a side elevational view as viewed from operators position.

FIG. 2 is a fragmentary end elevation looking from the right of FIG. 1.

FIG. 3 is a horizontal section view taken on the lines of 33 of FIG. 2.

FIG. 4 is a section elevation view on the lines 44 of FIG. 1.

FIG. 5 is an enlarged detailed elevation view of the clutch as seen in FIG. 4.

FIG. 6 is a schematic bottom view showing the arrangement of

gears

48, 50 and 51 on shafts 37, C and 53 respectively. The gears shown are immediately to the left of

gears

54 and 55 in FIGS. 1 and 3. The upward direction of the sight lines for FIG. 6 is shown by the arrows 6.6 of FIG. 1, and

FIG. 7 a plat diagram illustrating the motions of the cutter saddle and the cam which controls the cut of the cutter.

In the drawings, 11 is a horizontally slidable saddle movable left and right in FIG. 2, and carrying a vertical cutter spindle. The spindle is supported about a vertical-axis hearing held at the right side of the saddle as viewed in FIG. 1. The cutter spindle and bearing are not shown on the drawings. The cutter spindle with the cutter afiixed to its lower end, makes rotation and also vertical reciprocation, and is driven by a special mechanism to make the cutter cut the teeth on the work piece.

Patented Nov. 23, 1965 Since the cutter and driving mechanisms are not in the scope of the present invention, they are neither shown in the drawings nor are they here explained in detail.

12 is a transmission bar, one end of which is connected to the cutter saddle 11 with a screw joint 12' to make its elfective length adjustable, while the other end provided with a roll 13 is made to touch upon the surface of the cam 14 which controls the movement of the transmission bar 12 and therefore that of the cutter saddle from one side. For the same purpose the rack 12 is provided at the lower side of the transmission bar 12 to be in gear with the segment teeth 16 rotatably supported at the shaft 15, and these segment teeth are actuated to rotate anti-clockwise by a suitable means e.g. by a spring wound around the shaft 15, so that the roll 13 at the end of the transmission bar touches the surface of the cam 14 during the time the cutter is acting upon the work. 17 is a stop pin fixed on a part of the frame by which the segment teeth 16 are made to stand still at the very position when the roll 13 at the end of the transmission bar has moved with the rack 12" apart from the segment teeth 16 leftward to the retire stroke end 13 as seen in dashed lines in FIG. 2 together with the saddle 11 by the action of the oil cylinder 18. Thus the rack 12" of the transmission bar can again enter into gear with the segment teeth 16 when it comes back rightward toward the work in the beginning of the next cutting cycle. 18 is an oil cylinder which moves the cutter saddle rightward or leftward with its piston rod, attached directly to the cutter saddle, at the beginning and last of one cycle of working. 19 and 20 are working bars to actuate limit switches. Bar 19 first brakes the oil cylinder 18, 20 then cuts off the oil pressure to make that cylinder 18 powerless and at the same time starts the oil cylinder 26 (see

points

2, 3 on Sdll curve herebelow). This is done when the transmission bar carrying the cutter saddle has been moved rightward and the cutter approaches its cutting position.

Since the cam 14 has duty to control the movement of the cutter saddle as well as the cutter, it must have different shape according to the form and dimension of tooth to be cut as well as the mode of working e.g. two step cutting or three step cutting, so that it must be fixed on the cam holder 22 changeably eg by means of bolts. This cam holder 22, being provided with an anti-friction metal 23 in the side, is made to move up and down, sliding vertically in the space bounded by the frame 24 and a guide plate 25, fixed thereto, actuated by the piston rod 26 of another oil cylinder 26 through the bracket 27 fixed thereto.

Moreover at the upper part of this cam holder 22, there is provided a cam 28 and there is also provided a rack 29. The cam 28 is to move the shifter of the clutch which is hereinafter explained, while the rack 29, being put in gear with a toothed wheel 30 fixed on the shaft 37, drives said toothed wheel 30 when the cutter saddle is moved by the oil pressure in 18. At another time the rack 29 is driven by the toothed wheel 30 when the cutter saddle is moved with positive drive such as by toothed gearing 16, 12.

When the cam holder 22 is raised upward by the oil cylinder 26, the push rod 31 connecting at the lower end of the lever 32 moves leftward, moving the upper end of the lever 32 rightward through its fulcrum. By that motion of the lever 32, the acting rod 33 moves rightward actuating a limit switch to brake the oil cylinder 26. Thus the oil cylinder 26 is prepared to become powerless by being cut olf from the oil pressure.

Spaced from inclined lever 32, there is provided an inclined shifter lever 34, the latter (34) pivoted at the horizontal fulcrum pin 34' on the frame (see FIG. 1).

The upper end of 34 is loosely connected within a forked end of horizontal lever 34", which latter lever (34") is pivoted by a vertical pivot at an intermediate point to the frame. The upper end of the lever 32 is likewise loosely connected within another forked end of lever 34"; so that when the top of lever 32 inclines rightward, then the top of the other shifter lever 34" inclines leftward pulling the cap 34' to the right (in FIG. 1) by the two lower ends of the shifter lever 34.

Now since the cap has a conical inner surface, it presses the

ends

35 and 35 of the pawls 35 and 35' at the opposite side of the

fulcrums

35 and 35 keeping the pawls from the ratchet teeth 36, disengages the clutch against the force of the springs 35;, and 35 so that if the cap 34 is moved rightward by the shifter lever 34, the pawl ends become free and the pawls will soon engage with the ratchet teeth by the aid of the

springs

35 and 35 thus engaging the clutch in action.

After the clutch has been engaged as above, the cam 14 and its holder 22 are moved further upward, consequently the rack 29 rotates the shaft 37 through the toothed wheel 30. Then there are provided the associated

earns

39, 40, 41, 42, and 43 arranged as a multiple sectioned drum 38 at the other end of the shaft 37 and these cams face the acting rods respectively to actuate the following limit switches:

1the limit switch for changing rough cut to finish cut,

2the limit switch for relieving oil pressure within the oil cylinder 26,

3the limit switch for starting main electric motor, and

accompanying action,

4the limit switch for setting the upper limit of the motion of the cam 14, and accompanying action,

the limit switch for settling the lower limit of the motion of the cam 14, and accompanying action.

Thus there are five kinds of limit switches. The second switch is first actuated by cam 40 and acting rod 2. An impulse from the second switch opens an exhaust valve, which permits relief of pressure within oil cylinder 26, allowing the saddle 11 to return to its original position. Then the third switch is actuated by cam 41 and acting rod 3 to start the main electric motor (not illustrated).

If the main electric motor starts, its motion is transmitted from the shaft 44, through the toothed wheel 45 fixed thereto, to the toothed wheel 46 which is fixed on the sleeve fitted idly on the shaft 37, and further transmitted to rotate the

toothed wheels

47 and 48, fixed on the same sleeve, to the opposite direction with the shaft 44. Then the former toothed wheel 47 rotates the toothed wheel 49 at the left-hand side of the differential gear mechanism, while the latter toothed wheel 48, through the toothed wheel 50 supported on the counter shaft C, rotates the toothed wheel 51 at the right-hand side of the same differential gear mechanism at the opposite direction compared to the direction of rotation of the toothed wheel 49. Thus the pinion shaft 52 at the middle of the same differential gear mechanism is rotated at a considerably reduced speed compared to that of the shaft 44.

The rotating motion thus reduced is transmitted, through the shaft 53 upon which the pinion shafts are fixed, the toothed wheel 54 fixed on the same shaft, the toothed wheel 55 fitted idly on the shaft 37 and pawls 35, 35', to the ratchet teeth 36 and therefore the shaft 37 carrying the same ratchet teeth. Thus the shaft 37, through the toothed wheel 30 and the rack 29, drives the cam 14 in the reverse direction.

The clutch here used is purposely of ratchet type because it is needed to engage in one direction only; that is to say, the shaft 37 must rotate freely when it is rotated by the oil pressure through the rack 29 and the toothed wheel 30 and moreover the clutch must engage when the main electric motor starts and the cam 14 is driven in the reverse direction through the clutch and the gearing stated above. The differential gearing is utilized for getting a large degree of speed reduction in a comparatively narrow space.

When the main electric motor starts as already described, the mechanism which transmits a special combined motion of rotation and reciprocation to the cutter spindle, also starts. And according to the upward motion of the cam 14, the cutting of teeth upon the work will proceed with at first one turn of rough cut, and then a finish out following. Such change of cut is made by the action of a change gear (not illustrated), for changing the position of the cutter saddle through the cam 14 by the limit switch No. 1 actuated by the cam 39.

When the cam 14 reaches its up stroke end, the cutting of the teeth must be entirely finished. The limit switch No. 4 will control such point of up stroke, being actuated by the cam 42. At the same time, the main electric motor is stopped by cutting olf the electric current and the oil cylinder 26 is actuated by the same limit switch to move the cam 14 down.

When the cam 14 reaches its lowest position, which position has been controlled by the limit switch No. 5 actuated by the cam 43, the same limit switch 5 cuts off the oil pressure to the oil cylinder 26 and starts another oil cylinder 18 for making the cutter saddle 11 retire to its leftward stroke end to complete one cycle of gear cutting. At that position the Work is removed and next work is put on the work spindle for starting a new cutting again.

The manners of the motion of the saddle 11 and the cam 14 are plotted in FIG. 6, in which the time T and the distance of movement L are shown on abscissa and ordinate respectively. In the diagram, Sdll means the saddle 11, while 01114 the cam 14. And 0 means the term of oil pressure drive while P that of positive drive.

Annexed is the simple explanation of the

points

1, 2, 3, 4, 5, 6, 7, 8 on the curve Sdll as well as the points a, b, c, d, e on the curve Cm14.

1The position of the saddle at its most remote place from the work,

2The position of the saddle when a limit switch actuated by the acting rod 19 brakes the oil cylinder 18,

3The position of the saddle when a limit switch actuated by the acting rod 20 cuts off the oil pressure to the oil cylinder 18,

4The position of the saddle when the cam 14 begins to move the saddle toward the work for rough cutting, just before, the oil drive is changed to positive drive,

5Rough cut begins,

6Rough cut is changed to finish cut,

7After the cutting has been finished, the retirement of the saddle by the oil cylinder 18 begins,

8-The saddle retired at its initial starting position.

a The down stroke end from which the cam 14 is pushed up by the oil cylinder 26,

b The oil cylinder 26 is braked by the limit switch actuated by the acting rod 33, soon after, its oil pressure is cut off and positive drive begins by the actuation of the limit switch actuated by cam 41,

c Rough cut is changed to finish cut,

d At the up stroke end, the cutting completes, and the cutter stops, at the same time the cam 14 is moved down by the oil cylinder 26,

e The oil cylinder 26 sops and the cam 14 returns at the initial position.

As may be seen in the diagram, the cam 14 and the cutter saddle 11 are driven at high speed by high oil pressures when the saddle approaches to or is withdrawn from the work, so that the idle time is greatly reduced. But on the other hand when the real cutting is practiced, they are moved by a positive driving at a low speed and fixed precision, so that a precise cut can be ensured.

Also since all cutting steps are controlled completely and automatically, the efliciency will be enormously increased.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirt and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:

In an automatic electrically driven gear shaper wherein a cutter is powered for cutting action and a cutter saddle is moved horizontally and radially toward and from the vertically fixed axis of a worktable mounted in a fixed frame and carrying a workpiece, hydraulic system means for driving said saddle at high speeds during both its preliminary strokes wherein it approaches the work cutting position, and during its final strokes wherein it retires after cutting is completed, said hydraulic system means including a horizontal axis hydraulic cylinder fixed to the frame, and carrying therewithin a piston and a cylinder rod with an outer end of the latter fixed directly to a portion of said cutter saddle, whereby said cylinder rod and cutter saddle move unitarily and simultaneously with respect to said frame, and slower speed positive acting mechanical drive means for the saddle including a vertically movable side face cam mounted on the frame, and a horizontal motion transmission bar between and contacting the cam and saddle, said mechanical drive means operable upon the cutter saddle with a slower feeding motion during the intermediate stroke between the preliminary and the final strokes when said hydraulic means have been inactivated, the interchange in drive means from hydraulic to mechanical and vice versa being accomplished by means including a unitary multiple sectioned rotating drum cam with stationary horizontal axis, and located in an exposed accessible position at one end of the gear shaper, which sequentially operates a plurality of acting rods, each rod controlling a limit switch, the sequence of action of the limit switches aiding in the programming of the control of the electric drive, the powering of the cutter, and the rotating of the workpiece, the requisite pressures in the hydraulic system and the operative relationships of the positive acting mechanical drive means.

References Cited by the Examiner UNITED STATES PATENTS 2,198,882 4/1940 Monroe -10 2,374,901 5/1945 Sneed 90-1O 2,749,805 6/1956 Kendall 90-7 2,975,681 3/1961 Wildhaber 90-10 3,021,765 2/1962 Cobb 907 ANDREW R. JUHASZ, Primary Examiner.

LEON PEAR, Examiner.