US2183864A - Index mechanism - Google Patents

Description

Dec. 19, 1939. C, GR 2,183,864

INDEX MECHANISM Fild March 29, 1959 CLHHENEE J.GREEN Patented Dec. 19, 1939 INDEX MECHANISM Clarence J. Green, Worcester, Mass.,-assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application March 29, 1939, Serial No. 264,795

, 4 Claims.

The invention relates to indexing mechanism, particularly for automatic camshaft grinding machines such as disclosed in patent to Belden and Silven No. 2,022,178.

One object of the invention is to permit an automatic camshaft grinding machine such as disclosed in the aforesaid patent to be more quickly set up for grinding different types of product camshafts. Another object of the invention is to provide a dog bar having a plurality of series of actuating dogs and arranged so that any one of the series can be brought opposite the member to be actuated. Another object of the invention is to provide a series of pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing illustrating one of many possible embodiments of the mechanical features of this invention,

' Figure 1 is a perspective View of a camshaft grinder having the indexing mechanism of the present invention applied thereto;

Figure 2 is a view, partly in axial sectional view and partly in elevation, of the dog bar which is particularly a subject of the present invention, the center part of the dog bar being broken away;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a sectional view taken on the line 4-4 of Figure 2;

Figure 5 is an isometric view of the dog bar.

In the grinding of cylindrical shafting it is suilicient to rotate the shaft on centers and bring into contact with it a rotating and (relatively) transversing grinding wheel. In order to grind camshafts, some means had to be provided to move the grinding wheel or work piece, one relative to the other, to generate the desired cam contour. In a line of machines exemplified by the patents hereinabove referred to, the grinding wheel was mounted on a cross slide while the work piece was carried by the table or carriage capable of a longitudinal move- (Cl. 51 101) I ment. The work piece instead of being in a fixed position on the table or carriage was mounted in centers provided in a rock bar. The table was moved from one position to another to bring successive individual cams opposite the grinding Wheel. A series of master cams were provided to rock the rock bar and a master cam roller was movable to a position opposite a particular master cam corresponding to the product cam to be generated. m

The design of the product camshaft being determined by automotive engineering, it happened that the distance axially between successive individual cams was not uniform. In the patent to Silven No. 1,791,479 referred to, the 15 motion of the carriage was used automatically to bring the master cam roller opposite the desired master cam, the master cams being uniformly spaced. The apparatus of the present invention is shown embodied in a machine of this type..

Referring now to Figure l, the machine base is indicated at H] and on the upper surface thereof are formed V ways H and a fiat Way l2 for the support of a carriage [3 having complementary V ways l4 and a flat way I 5. This carriage I3 is, therefore, movable along the base 10 and automatic hydraulic mechanism to move it is. disclosed in the aforesaid patent to Belden and .Silven No. 2,022,178 while automatic me- 30 chanical mechanism to move it is disclosed in patent to Belden and Trefethen .No. 1,945,588, and so far as the present invention is concerned the carriage !3 might be manually moved to the various positions desired. 35.

Mounted on and afiixed to the carriage I3 is a table it, normally extending parallel to it butcapable of slight angular adjustment, if desired. Mounted upon the table H5 in a bearing I8 and another bearing not shown is a rock bar 20. 40 Fastened to the rock bar 20 is an adjustable tail center 21. The work piece or product camshaft W extends between the adjustable. tail center 2| and the head center formed on the end of a master cam spindle 23 supporting a 45 plurality of master earns 24. Fastened to the table It is a casting comprising a pair of bracket portions 25 and a connecting web 26, which casting supports a slideway 27 for a rack 28.

Extending between the bracket portions 25 is a 5 of the brackets 25. Connected to the pinion gear 33 is a small spur gear 35 which meshes with a somewhat larger spur gear 36 mounted on a stud 31 projecting from a lower portion 38 of the casting including the brackets 25. Meshing with the gear 31 is another spur gear 46 mounted on a stud 4i projecting from a boss 42 also constituting part of the casting including brackets 25 and the portion 38. On the end of the stud M is a star wheel 43. The star wheel 43 is a rotatable member and it is in effect a detent for actuating the rack 28 in a step by step movement responsive to contact with the dogs to be hereinafter described.

The master cam spindle 23 is journalled in the rock bar 20 and as the master cam spindle 23 revolves, the particular master cam 24 in contact with the roller 3! causes the rock bar 20 to oscillate on the table l6. Thus a product cam will be formed of a shape controlled by a master cam 24.

Any suitable means is provided to drive the product shaft W. For example, a motor, not shown, drives a worm 45 in a casing 46 on top of a bracket 47 mounted on the table l6, and

' the worm meshes with a worm wheel 48 in a casing t9 connected to the bracket 61, the spur gear 18 being connected by a shaft 50 with a spur gear meshing with a spur gear 52 connected to a sprocket gear 53 which is connected by a chain 54 to a sprocket gear 55 on the end of a shaft 55, some of these parts being mounted in the casing 51 as indicated. The shaft 56 is connected by a flexible coupling 53 to the master cam shaft 23. Any suitable means involving a hydraulic cylinder 65 may be used to rock the master cam shaft 23 away from the master cam roller 3| to permit indexing and this same motion will also move the product shaft W away from the grinding wheel 66.

The foregoing is more fully described in the patents hereinbefore referred to and, therefore, will not be further detailed herein. Referring now to all the figures, I provide a dog barwhich may consist of an end piece H and an end piece I2 mounted in journals '!3 and M in brackets 15 and 16 fastened to the machine base l9. Each end piece H and 12 has a portion which is square in cross section. The end piece H is rotatable to four different positions by means of a hand wheel 18 and may be held in any of these positions by means of a spring pressed plunger 19 operated by a handle 88 which enters any one of four holes 8! in the bracket 15.

I further provide four removable dog bar sections 82 each comprising two bars rectangular in cross section and, as shown in Figure .5, spaced apart by blocks 83, the pair of bars being suitably fastened to the blocks and there being blocks 83 at each end of the bars. Each assembly of the dog bar section 82 including the blocks 83 is fastened by means of screws 85 to portions of the end pieces H and I2, respectively, which are square in' cross section, and I may provide triangular prism blocks 86 fastened to the end pieces fl and 12 securely to lock the dog bar portions 82 in place.

I provide dogs 90 having enlarged bases SI and shanks 92 extending through the slots 93 formed between the bars comprising the dog bar sections 82 and secured in place by screws 94 and washers 95 located inside the dog bar. These dogs 90 operate on the star wheel to move the master cam roller 3| whenever the table I6 is moved longitudinally, and the dogs 90 can be spaced apart as desired on the dog bar. Furthermore, there may be four different arrangements of dogs 90 on the dog bar, one at each side thereof. The dog bar sections 82 can readily be removed by removing a pair of triangular prisms 86, one at each end of the dog bar, and a pair of screws 85 from the blocks 83. The machine may be made ready to grind different types of camshafts W simply by indexing the dog bar so far as the automatic positioning of the master cam roller 3! is concerned.

Referring now to Figure 1, it is impossible for the dog bar to be indexed excepting when a cylindrical portion 96 of the end piece H is under the star wheel 43. This is because in the turning of the dog bar, the prismatic shape thereof interferes with the stud 4| upon which the star Wheel 43 is mounted. It should be understood that by making the dogs 90 longer, the dog bar would be turnable whatever the relative position of the star wheel, assuming no other parts interfere, but I prefer to have this interlock so that the operator is required to move the table to the extreme left-hand position (as he stands in front of the machine), that is to the right in Figure 1, before he can index the dog bar. Otherwise if the dog bar were turned at a point where there were more dogs on one side of the star wheel in the case of one bar than in the case of the other, the machine would be thrown out of timing.

It will thus be seen that there has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a camshaft grinding machine, the combination with a grinding table, a rock bar mounted thereon, a master camshaft mounted on the rock bar, a master cam roller for contact severally with the master cams, and mechanism including a star wheel to move the master cam roller to different cams responsive to movement of the grinding table, of a plurality of dog bar sections parallel to each other and united and journalled in the machine whereby any dog bar section may be brought opposite the star wheel to actuate it.

2. In a camshaft grinding machine, the combination with a grinding table, a rock bar mounted thereon, a master camshaft mounted on the rock bar, a master cam roller for contact severally with the master cams, and mechanism including a star wheel to move the master cam roller to different cams responsive to movement of the grinding table, of a plurality of rows of dogs and means for bringing any one row under the star wheel to actuate it.

3. In apparatus of the class described, the combination with a plurality of master cams, an abutment, mechanism for moving one of the foregoing relative to the other to place the abutment selectively opposite different master cams, said mechanism including a rotatable member adapted to be actuated by dogs, of a plurality of sets of dogs and mounting means for the dogs permitting any one set to be brought opposite the rotatable member.

4. In apparatus of the class described, the combination with a plurality of master cams, an abutment, and mechanism for moving one of the foregoing relative to the other to place the abutment selectively opposite different master cams,

said mechanism including a detent adapted to be actuated by dogs, of a plurality of sets of. dogs and mounting means for the dogs permitting any one set to be brought opposite the detent.

v CLARENCE J. GREEN.

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