US1923390A - Lapping machine - Google Patents

Description

g- 1933. c. E. PARKHURST 1,923,390

LAPPING MACHINE Filed Feb. 15, 1932 2 Sheets-Sheet 1 M ATTORNEY."

Aug. 22, 1933. c. E. PARKHURST ,923,390

LAPPING MACHINE Filed Feb. 15, 1932 2 Sheets-Sheet 2 Fig [7 I Z0, PINVENTOR. I BY WflLI/PY, 7%RMMZ M ATTORNEY.

Patented Aug. 22, 1933 LAPPING MACHINE Clyde E. Parkhurst, Moline, Ill., assignor to Moline Tool Company, Moline, 111.

Application February 15, 1932.7 Serial No. 593,015

1 Claims. (01. 51-1843) f My invention has reference to a lapping or honing machine, and as set forth herein it embodies a mechanism more specially designed for use on the inner wall of a brake drum, or

5 other cylindrical body having a closure or other obstacle at one of its ends or within its bore, which interferes with the movement of the lapping tool entirely through the piece of worle.

'The invention consists of alapping head, supported by a spindle in the usual manner, so as to be capable of a rotary movement, and also movable axially, for translation of the head toward and into a piece of work and the consequent retraction of the head therefrom. lhe head is of circular formation, and is provided at intervals on its periphery with stones of, abrasivematerial. By means of other instrumentalities carried by the lapping head the stones may be adapted and adjusted to their work..

Stones of the kind mentioned are usually in the form of blocks of 'a length corresponding approximately with that of the head with which they are connected, and in the performance of said blocks they are moved gradually into the part that is. being honed, with the result that the ends of the stones which first enter the piece of work perform a greater part of the opstones thatfollow,

eration than the ends-oi the and possibly enter the work for a short distance only. As a result the stones become worn unevenly, with a tendency to assumea wedge or tapered form, with the face of the stoneinclined from one end to the other, rendering the same inefficient and useless carding thereof.

One of the purposes of the present invention is to provide supports for thestonesof. such a character that they can be quickly reversed in position upon becoming worn, as above mentioned, and, upon being again put in use, neutralize and correct the unequal condition.

Another feature of the invention consists in the provision of novel mechanism for the adjustr ment of the stones to their work, so as to gradually increase the working circumference of the tool as the work progresses. Associated therewith is means for holding the stones yieldably against outward movement.v f

The above named, and other features and advantages of the invention will more fully appear from the following specification, reference being had to the accompanying drawings, in which;

Fig. 1 is a vertical medial section of a lapy The reference number by means of bolts 5.

and calling for the disping head, as it appears in operation in a drum, which is also sectioned.

Fig. 2 is a horizontal section line '2-2 of Fig. 1. i i

Fig. 3 is afragmentary view of the outer rim of the lapping head, showingone oithe stones 33 and the manner of reversing the position thereof. 4 The figures of the drawings areconfined to the lapping head and parts'immediately asso-- ciated therewith, it being understood that said mechanism-s form parts of a. larger machine; containing the usual feeding and driving elements for the head.

brakeon the broken 1 indicates a spindle, 7 vertically disposed as set forth herein, to the. lower'end of which spindle is connected a. coupling 2, provided with an annular flange 3, with which is connected the web 4 of a lapping head,

Projected downwardly fromsaid web is a circulr head 6, centrally of which is a cylindrical core l also depending from the web portion 4. In. the wall of the head 6 is a pluralityof bushings 8, in which are slid-ably and rotatably mounted shafts 9, so

reduced at their inner endsinto pins 10, rotata-, bly mounted in bearings 11 in the core 7. The ends of the pins 10 are beveled at 12 to-con form to the lower part of a cylindrical expansion element l3'supported in the core 7 so as to be movable freely therein. The lower part 14 of said element is in the form of an inverted frustum, and said expansion element is supported entirely by the ends of the inwardly projecting pins 10, so as to move freely or 901 float in said core. I

In the upper end of the element 13 is a recess 15, containing an anti-friction ball 16, upon which rests the lower end of a rod 17, passing upwardly through an opening 18 in the lower part of the coupling 2 and a bore 19 in the lower end of the spindle 1. Fixed to the upper. end of the rod 17 is a cross-pin 20, the ends of which pass outwardly through a slot 21 in the spindle l, and are connectedwith a collar 22 slidable on said spindle. On the lower end of the spindle 1 is mounted a plate 23, separated from the spindle by a ball-bearing outfit at 24, permitting rotation of the spindle independently of said plate. At one end the plate 23 is 10 extended into an arm 25, shown partly broken away, and designed for a vertical slidable' connection with a fixture in proximity to the lapping head, as, for instance, the main column of the machine. llQ

I at 36, and having an end portion at 36*, par- 7 Supported on the plate 23 is a bracket 26 in which is pivoted one end of a yoke-arm 27, and provided at its other end with a recess 28- in which is pivoted an upwardly extended bolt 29. On the threaded end 30 of said bolt is a'thumbnut 31, by the proper operation of which the yoke-arm 2'7 and rod 1'? can be forced downwardly, imparting a similar movement to the expansion element 13. l

To the outer ends of the shafts 9 are attached shoes 33, held loosely in recesses 34 in the rim of the head 6, transversely of said rim. Fixed in said shoes are stones 35, of suitable abrasive material, and adapted for operation in the inner wall of an automobile brakedrum, indicated tially closing the same, and limiting the move.- ment of the stones downwardly. On each of the shafts 9 is a coiled spring '37, interposed between the bushing 8 and a collar-nut 38, having a threaded engagement with the shaft, for adjustment thereon to increase or diminish the force of the spring. As the stones 35 are fed into the workthe lower ends thereof sustain the greater amount of wear, and as the stones become worn so as to be out of true they may be inverted in position, by engaging the ends thereof with the fingers of the hand and drawing the stone and its mounting outwardly until they'are clear of the head 6.- The stone and its shoe can then be turned end for end, in the mannershown in broken lines in Fig. 3, and said parts re-seated in the 011%1'11181'34, In this operation the spring 3'7 is compressed, increasing the tension thereof, and upon the'stone being released it is again held yieldably in place by the spring.

It will be noted that the action of the mech-' anism for radial adjustment of the stones is a positive one, and works against the force of the springs 3'7. When the work of the tool is started in a brake-drum the stones are properly positioned by the operation of the thumb-nut 31, and as the work proceeds the wear upon the stones or upon the wall of the drum can be compensated for by additional adjustment of the thumb-nut, to further expand the circle of the abrasive elements.

The stones 35 and their supporting shoes are formed to project downwardly beyond the wall of the'head 6, as shown, so as to give ample clearance for said stones in the lower part of the drum.

What I claim, and desire to secure by Letters Patent, is:

1. In a lapping machine, a spindle mounted to rotate and reciprocate, a circular head fixed to said spindle, a plurality of stones mounted pivotally on the periphery of said head, and means for holding said stones normally and yieldably against a reversal in position.

2. In a lapping machine, a spindle mounted for rotation and reciprocation, a head fixed to said spindle comprising an outer circular wall provided in its rim with transverse channels and a central cylindrical mounting, spaced from said wall, a plurality 'of-shafts journalled in said wall atone end and in the mounting at the other end, and having extensions into said mounting, shoes fixed to the outer ends of said shafts and normally positioned in said channels, stones fixed in said shoes, springs on said shafts holding the same with said shoes held yieldably in said channels, and an expansion element in said mounting, bearing against the ends of said shafts, and operating against the force of said springs.

3. In a lapping machine, a spindle mounted therein for rotation and movement longitudinally, a head fixed to said spindle comprising an outer circular wall provided in its rim with spaces for stone holding tools and a central cylindrical mounting, a plurality of supports held rotatably and slidably in said wall and mounting and extending into the mounting, stone holding tools fixed to the outer ends of said supports, and normally occupying said spaces, stones carried by said tools, said tools being capable of being rotatably shifted in position upon being withdrawn from said spaces,

springs connected with said supports, and holding the same with said stone holding tools held yieldably in said spaces, an expansion element in said mounting, engaging the ends of said supports, and 'mea-ns'for adjustment of said expansion element to move said stones outwardly against the force of said springs.

4. In a lapping machine, a spindle mounted therein for rotation and reciprocation, a head fixed to said spindle and provided in its rim with stone holding spaces and having a central cavity, supports extending outwardly from said central cavity to said spaces, stone holding tools fixed to the outer ends of said supports, stones carried by said tools, springs onsaid supports holding the same yieldably in'inward positions, an expansion element in said cavity in engagement with the inner ends of said supports, a plate supported on said spindle and provided with means for, slidable connection with a fixture,adjustment devices on said plate, and means for imparting the movement ofsaid adjustment devices to said expansion elementto move said supports outwardly against the tension of said springs. I

CLYDE E. PARKHURST.

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