US2308352A - Grinding tool speed reducer - Google Patents

Description

Jan. 12, 1943. J BLAZEK ETAL 2,308,352

GRINDING TOOL SPEED REDUCER Filed March 11, 1940 25 INVENTORSr JoH/v Y. ELAZEK ATTORNEYS,

BY G/LEERrZ'ISL-AR Patented Jan. 12, 1943 GRINDING TOOL SPEED REDUCERv John Y. Blazek, Bedford, and Gilbert E. Sears, Cleveland, Ohio, assignorsto Lempco Products, Inc., Bedford, Ohio, a corporation ofOhio Application March 11, 1940, Serial No. 323,260

4 Claims.

This invention relates, as indicated, to a grinding tool speed reducer, and has reference more particularly to a speed reducer adapted for use in conjunction with a crankshaft grinding tool of the type comprising a split ring-like member having abrasive material along the inner periphery thereof, which member is adapted for rotation about a crankshaft pin. Such grinding tools are well known in the art and are particularly disclosed in United States Patent No. 2,179,465, issued November 7, 1939, and invented by John Y, Blazek and United States Patent No. 2,171,- 417, issued August 29, 1939, and invented by McGovern, et al.

In grinding crankshafts with a tool of the character described, it has been found that with any given motor or source of power a satisfactory finish could be produced on crankshaft pins of diameters only within a certain limited range. A crankshaft grinding tool of the character described, to be commercially successful, must be capable of accommodating a vast range of crank pin diameters many of which are outside of the said limited range. One of the virtues of such a crankshaft grinding tool is that its use does not necessitate the removal of the crankshaft from the engine and it follows that certain space limi-s tations must be observed. Such space limitations defeat any attempt to utilize large driving pulleys.

The primary object of this invention has been to provide a speed reducer of the character described, which, when attached to a motor, is capable of imparting various peripheral speeds to the grinding tool.

Another object of this invention is to provide a device of the character described which can be quickly and easily inserted in the driving mechanism, and which is compact, simple in mechanical features, and economical to manufacture.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing, forming part of this specification, and in which like numerals are employed to designate like parts throughout the same, Fig. 1 is a fragmentary side elevation of a device embodying this invention mounted on a crankshaft; Fig. 2 is a front elevation of Fig. 1; Fig. 3 is a view partly in elevation and partly in section taken substantially along the line 3-3 of Fig. 2, and Fig. 4 is a view similar to Fig, 1, but showing a modification thereof.

Referring more particularly to Figs. 1 and 2,

there is suitably mounted upon a frame or base plate 5 a motor or source of power 6, and a speed reducer embodying this invention indicated generally by reference numeral 8. A belt ll] links together the speed reducer and the grinding tool indicated generally by reference numeral I2, the latter being illustrated in grinding position upon a crankshaft. I

As is seen in Fig. 2, the grinding tool in general comprises a split ring-like pulley made up of two semi-circular members l5 which, by means of links I! and removable pins l8, form a substantially continuous pulley. Abrading material is suitably carried along the inner periphery 20 of each of the members l5. It is thus seen that actuation of the source of power rotates the grinding tool and abrades the crank pin. The grinding tool per se forms no part of this invention, and consequently will not be further described. Referring now to Fig. 3, a detailed description of the speed reducer follows: Suitably secured to the plate 5, as by means of bolts 25, is a housing 26 which is sealed by a cover plate 21 secured thereto by bolts 28. Rotatably supported at one end by the housing 26 is a shaft 30, which for coupling purposes is provided with an axial bore for the reception of a driving shaft 3| of the source of power 6, the said shafts being drivingly interconnected by suitable means, such as a set screw 32. The shaft 30 is further provided with gear teeth 34, which mesh with a gear 35, the latter being supported in amanner to be presently described.

Suitably supported, parallel to the shaft 30, at one end by the housing and at the other end by the cover, is a shaft 31 upon which is suitably rotatably mounted a pinion 38. This pinion is provided with an axial annular projection 39 upon which is mounted said gear 35. The pinion 38 and gear 35 are locked against relative rotation by means of a key 40, and locked against relative axial movement by means of a set screw 4 I A gear 45, which meshes with the pinion 38,

is rotatably supported by the cover 21 and is provided with an axial projection 46, upon which is mounted a large pulley 47, the gear 45 and pulley 41 being locked together by suitable means, such as a key 50. The other end 5| of the shaft 30 is of reduced diameter and has secured thereto by suitable means, such as a key 52 a smaller pulley 53. Suitable anti-friction and spacing means, such as a washer 55, may be provided.

It is understood that pulleys 4'! and 53 may take the form of sprocket-wheels in which event a chain would be utilized in lieu of the belt 10;

and that pulleys 41 and 53 may take the form of gears in which event the outer periphery of the grinding tool l2 would take the form of a gear and suitable gearing would connect pulleys 41 and 53 with the grinding tool l2.

From the foregoing description, it will be apparent that the smaller pulley 53 is directly driven by the source of power and that the larger pulley 4'! is, by means of gears 45, 38, 35 and 34, indirectly driven by the source of power. It will also be seen that the relative peripheral or angular velocity of the smaller pulley 53 and the larger pulley 41 is a function of the reducingratio of the gear train. We have found that by. proper selection of the gear train ratio, and diameters of the pulleys 53 and 4! and of the grinding toolv l2, the same source of power and grinding tool can be utilized to produce a satisfactory-finish upon an increased variety of crank pin diameters and also upon an increased variation in the de gree of crank pin hardness. The harder and larger the crank pin the fewer the R. P. M. required to produce a satisfactory finish so that with a given grinding tool and source of power, the hardness and diameter of the crank pin to beground will determine which of the pulleys 53 or 41 is to be utilized.

Since all that is needed to change thespeed of the grinding tool is to switch the belt from one pulley to the other, the change may be quickly and easily accomplished. Alignment of the speed reducer with the motor is facilitated by the insertion of shaft 3| into the axial bore of shaft 30. Installation is rendered rapid by manipulation of set screw 32 and bolt 25. The housing 26, being no higher nor wider than the source of power, is extremely compact. Due to the simplicity of the mechanism, manufacture is economical.

In the alternative illustrated in Fig. 4, the

speed reducer 8, instead of being secured to, the l plate 5, has secured thereto an arm 60, which, when the reducer tends to rotate in either direction contacts the plate '5 and limits such rotation. The sole support for the reducer is the shaft 3!.

It is to be understood that the forms of our invention, herewith shown and described, are to be taken as preferred examples of the sameand that various changes in arrangement of parts may be resorted to without departing from the spirit of our invention nor the scope of the subjoined claims.

Having thus described our invention, weclaim:

1. In a speed reducer a housing comprisingtwo elements, a gear having an axial projection and an axial bore, said projection being journalled in one of said elements, a pulley keyed to said projection exteriorly of said housing, a shaft one end of which is journalled in the other of said elements and the other end of which is journalled in saidaxial bore and projects exteriorly thereof, a pulley keyed to said last-named projection, a gear in mesh with said first-named gear rotatably supported by said housing and having an axial projection, a gear non-rotatably secured to said last-named projection and a gear driven by said shaft in mesh with said last-named gear.

2. A drive unit comprising in combination a source of power, a shaft rotatably driven thereby, a rotatable housing, a pair of members each adapted for conveying energy to a tool, gearing means within said housing for driving each of said members at a different speed, one of the elements of said means having an axial bore for accommodating said shaft, means for drivingly connecting said first-named means and said shaft, said shaft being the sole support for said housing, and means for limiting rotation of said housing.

3. In a speedreducer, a housing, a gear member interiorly of said housing, a pulley member exteriorly of said housing, one of said members being provided with a projection journalled to said housing and the other of said members being driven by said projection, said member having said projection being provided with an axial bore, a shaft" journalled to said housing and to said bore and extending beyond said projection, a pulley driven by one end of said shaft, the other end of said shaft being provided with an axial bore for coupling purposes, said shaft having gear teeth thereon, and reduction gearing interconnecting said gear teeth and saidgear member whereby actuation of said shaft actuates said,

pulley member and said pulleys simultaneously at different angular velocities.

4. A drive unit comprising a source of power,

a shaft rotatably driven thereby, the housing rotatable relatively to said shaft, a pair ofmembers each adapted for conveying energy to a tool, means withinsaid housing and driven by said shaft for driving one of said. members at one speedand for simultaneously driving another of said members at another speed, said shaft being the sole support for said housing, and means for limitingrotation of said housing.

JOHN Y. BLAZEK.

GILBERT E. SEARS.

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