US1760493A

US1760493A - Portable grinding tool

Info

Publication number: US1760493A
Application number: US207168A
Authority: US
Inventors: Ernest A Hall
Original assignee: HALL Manufacturing CO
Current assignee: HALL MANUFACTURING Co
Priority date: 1927-07-20
Filing date: 1927-07-20
Publication date: 1930-05-27
Anticipated expiration: 1947-05-27

Description

May 27, 1930. E, A HALL PORTABLE GRINDING TOOL Filed July 20, 1927 Patented May 27, 1930 UNITED srArEs P TEN-r OFFICE ERNEST A. HALL, OF TOLEDO, OHIO, ASSIGNOR TO THE HALL MANUFACTURING 60.,

' OF TOLEDO, OHIO, A. CORPORATION OF OHIO PORTABLE GRIN DING TOOL Application filed July 20,

p This invention relates to grinding tools and particularly to those of a portable nature adapted for grinding the valve seats of internal combustion engines.

a An object of the invention is the provision of a tool of the character described, which s rapid, accurate and eficient in its work and is an improvement in certain respects on the tool heretofore invented by me and covered to by pay Patent No. 1,636,560, dated July 19,

The invention is fully described in the following specification and one embodiment thereof illustrated in the accompanying drawlt ings, in Which,-

Figure l is a central longitudinal section of a tool embodying the invention mounted in operative relation to the valve seat of an engine cylinder, Figs, 2 and are reduced at sections, respectively, on the hnes 2-2 and 3-3 in Fig. l, with parts broken away, and l ig. d is a sectional view on the line t-d lll fieferrin g to the drawin s, l designates an $55 engine cylinder with the ead cap thereof removed to render the valve seats accessible for grinding, one of which seats is shown and designated 2. Below and coaxial with the valve seat is provided the customary valve to stem hearing, which, in the present instance,

is formed by the bushing 8. I

The tool embodying the invention includes a support or pilot member 4, which comprises a stem adapted to be fitted at its lower end down into the valve stem bearin 3, whereby it is supported in true centere relation to the valve seat 2, the upper end of the stem being rejected a distance above the valve seat... order to accurately center the stem l with respect to the valve seat and to firmly hold it in such position, the stem has a tapered ortion 5 which has centering ooaction with t e upper end of the bearing 3 and has a nut 6 threaded on its lower end and provided with a tapered extension 7 adapted to fit into the lower end of the bearing to have centering coaction therewith. The tool proper, separate from the support or pilot 4 includes in its present embodiment, inner and

outer shafts

8 and 9, respectively,

1927. Serial 1T0. 207,168.

the outer ,shaft being carried by and mounted to rotate in a casing or holder 10 and the inner shaft being mounted in the outer shaft for free turning movements relative thereto. The shafts project at their lower ends below the casing 10 and the outer shaft 9 carries a grinding wheel 11 at its lower end having a grinding face suited, for grinding coaction with the valve seat 2. This wheel, however, is not intended to have simultaneous coaction with the valve seat entirely around the circumference thereof, as in my former Patent No. 1,636,560, but is odset with respect to the center of the valve seat so that only one side portion of the grinding wheel has coaction with the annular seat or surface to be ground. This lateral ofisetting of the grinding mem ber ll with respect to the valve seat is accomplished by providing the lower end of the inner shaft 8 with an eccentric bore 12 into which the upper endof the stem l fits in a manner to permit the shaft or sleeve 8 to have both rotary and axial movements thereon. lit is apparent that a turning of the inner shaft 8 on the stem 4 will edect an annular shifting of "the point of bearing or grinding coaction of the grinding member 11 with the valve seat, and that such coaction will be carried entirely around the valve seat by a complete turning movement of said shaft.

For efiective work, the shaft 8 should be slowly rotated while the shaft 9 carrying the grin-ding member 11 should be more rapidly rotated. For this purpose, power transmission means is carried in the upper enlarged portion of the casing 10 and communicates rotation at the requisite speed from a common source to the two shafts. In the present instance this mechanism comprises a maindrive s aft 13 journalled in the upper enlargement of the casing 10 transversely thereof at one side of the upper end portion of the shaft 9 and has one end connect-ed, pref erably by a flexible shaft 14, to a suitable power source. The shaft 13 is also connected through a train of speed reduction gears 16 to a large gear 17 on the upper end of the inner shaft 8, which shaft end projects above the upper end of the outer shaft 9 for such purpose. It is thus apparent that both shafts a bar 11 about its axis and the other 8 and 9 are rotated at relatively different speeds, one for the purpose of imparting a rapid grinding rotation to the grindin memor the purpose of imparting a slow revoluble shiftmg movement to the seat contacting side of the grinding member to cause it to repeatedly the seat during the grinding operation, than is possible by having the grindin member arranged concentric to the seat to e ground and simultaneously contacting with such seat entirely around its axis, as is the case with the tool described in my said former Patent No. 1,636,560,

' The tool with its abrading member is supported with respect to the valve seat, and t e grinding pressure of the abrading member thereagainst is gauged in the same general manner as described in said former patent, namely, b projecting a gauge rod 18 down through t e u per end the casing 10 and axially throug the shaft 8 into engagement at its lower end with the upper end of the stem 4, the upper end of the rod 18 being threaded in the upper end portion of the easing to facilitate longitudinal adjustment of the rod. A knurled head 19 is provided on the outer end of the rod 18 to facilitate turning. The rod 18 is locked in adjusted position by a set screw 20.

- The outer shaft 9 is rotatably centered within the casing 10 by upper and

lower bearing sets

21 and 22, respectively, which are mounted in the reduced neck or lower end portion of the casing 10 and are spaced by a sleeve 23, which, in the present instance, is fitted on the shaft 9 and secured thereto by a set screw 24. The lower bearing 22 rests on an inturned flange 25 at the lower end of the casing and also engages a shoulder formed at the inner end of an enlarged portion of the shaft 9 which rojects through the openings formed by the ange 25 and a stuffing box carried thereby. The upper bearing 21 is held to its seat on the upper end of the sleeve 23 by a collar 26 threaded in the upper end of the neck ortion of the casing 10, and this in turn is loclfed in adjusted position by a lock nut or collar 27. A sleeve 28 encircles the shaft 9 within the

collars

26 and 27, having its lower end thrust against the bearing 21 and its upper end thrust against the gear 15 on the shaft 9. a

The inner shaft 8 is supported within the shaft 9 by the shouldering of the lower hub end of the gear 17 against the upper end of the shaft 9. The portion of the casing 10 through which the rod 18 is threaded comwhen the cap has been removed.

It is apparent that upon removal of the cap 29- the shaft 8 and its car 17 may be withdrawn upward throug the casing opening and that after the grinding member 11 has been removed from the shaft 9 and'the

col lars

26 and 27 removed from threaded engagement with the casing 10, said outer shaft, the

bearings

21 and 22 and

sleeves

23 and 28, together with the gear 15 on said shaft, may be removed as a unit from the casing.

I wish it understood that my invention is not limited to any specific construction, arrangement or form 0 theparts, as it is capable of numerous modifications and changes without departing from thespirit of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a tool of the class described, a guide fixed with respect to the work, a shaft rotatable on said guide in eccentric relation thereto, a second shaft rotatable on said first shaft, a rotary abrasive member carried by the second shaft without said guide, and positively driven intergeared means for imparting rotation to said first shaft about said guide and to the second shaft about the first shaft.

2, In a tool of the class described, a guide fixed with respect to the work, a shaft rotatable on said guide in eccentric relation thereto and longitudinally movable thereon, a second shaft rotatable on the first shaft, a rotary abrading member carried by the second shaft without said guide, and means for imparting rotation to each of said shafts at relatively difierent speeds having a fixed ratio to each other.

3. In a tool of the class described, a guide fixed with respect to the, work, a shaft rotatable on said guide in eccentric relation thereto and longitudinally movable thereon, a second shaft rotatable on the first shaft and having a rotary work abrading part without said guide, intergeared means for imparting rotation to. each of said shafts, and means adjustably cooperating with said guide to move the shafts longitudinally of the guide.

4:. In a tool of the class described, inner and outer shafts axially movable together and mounted one on the other for free relative rotary movements, an abrading element carried by the outer shaft, a pilot engageable with the inner shaft, means for detachably securing the pilot in position to hold the inner shaft and the other shaft with their axes in laterally ofiset relation to the center of the work, and intergeared means for imparting rotation to each of said shafts with the rotation of one different from that of the other, and

means connecting the pilot and outer shaft through the inner shaft and operable in operation with the pilot during .a running of the outer shaft to axially adjust the shafts and abrading element toward or away from thework.

5. In a tool of the class described, a hollow casing having an opening at one end thereof, a removable closure member for said opening, inner and outer shafts mounted one on the other within the casing for free relative rotary movements and projecting from the opposite end of the casing to said opening, an abrading element carried by the outer shaft without the casing, a pilot engageable with the inner shaft, means for detachably securing the pilot in position to hold the inner shaft and the other shaft with their axes in laterally offset relation to the center of the work, intergeared'means for imparting rotation to each ofsaid shafts withthe' rotation offone different from that of the other, and means carried by said closure, member and adapted to cooperate with the pilot during a running of the shafts to effect an axial adj ustment of the abrading element toward and away from the work.

6. In a tool of the class described, a casing, two shafts mounted one within the other in the casing for rotary movement relative to each other and to the casing, the outer shaft projecting beyond the casing and having a rotary work abrading member, aguide adapted to be fixed with respect to the work and v having engagement with the inner shaft to cause its axis and that of the outer shaft to have a relative movement about a predeter- 'mined center when the inner shaft is rotated, and means mounted in the casing for driving 40 said shafts at different speeds having a definite predetermined ratio. In testimony whereof I have hereunto signed my name to this specification. ERNEST A. HALL.