US2449791A - Work holder for lapping lathes - Google Patents

Description

Patented Sept. 21, W48

. STATES FAT E'NT OFF ICE;

WfiRK HOLDER FOR MAPPING LATHES Henry H; Silverman Jamaica, N;- Y. Application December 10, 1946, Serial N. 715,272 1 Claim. (01. 51 -238) This-invention relates to devices for grinding or'l'apping sma1ldecorative metallic objects of anornamenta1character associated with watches; jewelry, and the like.

In lapping anarticle, the same is ground, polishedor 'woi'n away by a rotary disc of soft metal, wood, leather, or other material that is charged with an: abrasive or polishing powder. In this manner various objects are cut or shaped tea desired configuration or form, the same be ing" applicable to hard and soft metals and other materials.

Heretofore the practice in lapping has been to holdthe object in ones hand thus to present itto-therotary grinding or polishing element, sometimes withthe aid'of an improvised support or attachment. The results obtained lacked accuracy. Thus if a polygonal article was being-lapped; the dififerent sides would vary in length or-otherwise. i

It is therefore an object of the invention to provide improved means for avoidingthe difiicul'ties mentioned.

Another object of the improved means of apartieularly simpleand inexpensive nature, and desirably applicable to existing lathes performing locking operations witl'r uni rmity and precision, and yet witnthe required convenience. and flexibility of manipulation.

Another object of the invention is the provision" of a-device of the nature set forth having improved means for presenting the work at any required angle to the face of the lap whiie the feeding of the work may be; performed manual-lytowsuit the judgment and feel of the skilled operator.

Another object of the inventionis to furnish adevice of" the type mentioned having an improvedprecision-adjusted work table ad apted to veryclosely approach the lap for: accurately supporting extremely small objects.

Other objectsand advantages of the invention will" become apparent as the specification proceeds. i

With the af'oresaid obiectsin view, the invention comprises thenovel features, combinations and-arrangements of parts hereinafter described by the same reference characters throughout the' several views.

In the drawing; Figure 1 is a fragmentary view' in side elevainvention is to furnish Fig. 4 is aside view of an angular adjusting" element carrying the work table, a portion of which is shown in section. i

Fig. 5 is a top plan view of the work table and its angular adjusting element of Figure 1;

The advantages of the invention as hereout-'- l inedare best realizedwhenall-of'its featuresand instrumentalities are combined; but useful embodiments may be produced involving less than the whole.

It will be obvious tothose skilled in. the art to whichtheinvention appertains, that the same may ice-incorporatedin several differentcon-- struotions. The accompanying drawing, there-- fore, is submitted merely-as showing a preferred enemplification of the invention.

Referring in detail to the drawing, Hi denotes: the bed of any conventional lathe, the same comprising a pair of bars It and liisuitably grooved or otherwiseshaped as at I3 to form a track alongwhich is adjustably movable any suitable tool or workholder, inthis-instance the base i l of a motor I5 carrying a lap 16 of atypehereinbeforedescribed.

Theusual-practice is that the lap I6- isro-- tatedby a horizontal shaft ll, with the lap l'ying in a verticai plane parallel to the lathe -bed" Hi: However, the invention is not limited to this particular arrangement, because the lap [6 may also rotate-ina horizontal or other plane.

Formed; in thebars ii and I2 of the lathe bcd" Mi -are the holesor openings iii for slidably receiving horizontal" shafts or rods: l-9 and 2c, thisserving to exemplify a carriage: or track projecting from a side ofthe lathe and serving. for movement. of thework toward and away fromthelap: ES Bypassing the rods I9: and 20 through both of the-bars H: and I2, a strong and accurate support is obtained; Mountedon, the rods lt-and zli is a frame 2 i desirably of askeleton character, and: so fixedly related to the rods necessary. To permit free passage of the screw with relation to the bars 22 and 23, the openings 21 therein afford a clearance with the screw. In the space 28 between the bars 22 and 23 is a circular nut 29 or the like threaded upon the screw and fitted with precision between these bars, the structure being such as to avoid any lost motion or backlash. Similarly snugly fitted in the space 28 is an arm 30 pivoted on the bars 22, 23 by a pin 3| extending therethrough' Also disposed in the space 23 is a stop element 32 for a purpose hereinafter described. This element is formed with a hub 33 receiving the rod l9 and being adjustably locked thereon as by a set screw 33a.

It will now be seen that upon turning the nut 29, the frame 2| is movable toward and away from the bed of the lathe without distrubing any of the parts carried by said frame.

The arm 30 is generally upright but desirably atan angle to the vertical. Threaded in this armis a set screw 34 bearing upon the relatively fixed stop member 32. The latter may be so shaped as to obtain any desired rate of change of angle of the arm 30 by turning the set screw 34.,- As the angle changes, the point at which the set screw bears on the stop shifts along the latter. A rotatable or angularly movable disclike member 35 is pivoted at 36 on the arm 30 at the upper end thereof. This pivot may be ofiset with relation to the lap shaft IT. For a coarse angular adjustment of the member 35, the lower section thereof may constitute a gear 31, the upper portion of the arm 30 being forked at 38 to receive this gear section. Suitable means is provided mounted on the arm 30 for releasably selectively engaging the teeth of the section 31. Accordingly the arm 30 may have a slot 39 therethrough communicating with the adjustment gear teeth. On one side of the arm are the lugs '40 for pivotally mounting at 4'] a finger 42 which passes through the slot 39 to the opposite side of the arm 30. The upper edge of thefinger 42 is shaped to accurately fit between the gear teeth to adjus tably lock the member 35 without backlash. A tension coil spring 43 is connected to the finger piece 42 and to a lock 44 on the arm 30 thereby maintaining the finger piece in locking position subject to easy release when the operator depresses the free end of the finger. It will be noted that the member 35 is angularly adjustable in the plane of the adjustment afforded by the set screw 34 and provides acoarse but rapid adjustment while the set screw 34 furnishes a fine adjustment. The coarse adjustment is of a precision character.

Formed in the upper portion of the member 35 is an open-ended slot 45 for snugly receiving an interchangeable member 46 adapted to project to any desired degree beyond the member 35. This member 43 is fixedly secured in position by pins 41, 48 passing through the member 35. The member 46 is formed with an open-ended slot 49 for receiving a depending flange 50 of the work table 5|. The pin 41 passes through this flange 50 whereby the work table 5i is settable about an axis at right angles to the adjustments provision described. The flange 50 and the work table 5| taper toward the lead edge 52 of the work table to permit this edge to be in close proximity to the lap It in different angular positions of the work table. At this rear edge, the work table may be formed with a downwardly and outwardly depending wall or flange 53. Fixedly connected or integrally formed with the member 35 is a generally rectangular frame 54 having a rear section 55 and side sections 56, the latter inclined downward if necessary according to the shape of the member 35, to which they are affixed. The frame 54 embraces the flange 53 and aifords ample room for tilting of the work table about its axis 41. The tilting movement of the work table is controlled by a plurality of vertically spaced set screws 51, 58, threaded through the frame section 55, and respectively located above andbelow the pivot axis 41 and adapted to abut the flange 53. For angularly setting the work table 5| either one of the screws is moved toward the right and the other in the opposite directions, and then both screws are tightened to hold the work table fixedly in a required angular position.

The operation of the device will now be briefly described. The work table 5| affords a smooth plane surface whose leading edge 52 is in close proximity to the rotating lap I6 so that small articles that are to be lapped are caused to rest snugly on the work table, and are fed toward the lap directly by the fingers of the operator who relies upon his skill and judgment to produce the proper degree of grinding or polishing. I have found that this operation and method of control is ample for all practical purposes to anyone skilled in the art. It provides a precision guide while at the same time facilitating the use by the operator of feel to obtain the desired results in a much more convenient and suitable manner than if a mechanical feed were used which might not be adapted for very small ar- T tides and which would interfere with the feel to which the operator is accustomed. Because the work table approach is very close to the lap, an adequate support is furnished even for relatively minute objects. The lap may also be coated with rouge or other materials for furnishing a very high polish.

The device is set up for use by first giving the member 35 a coarse adjustment, which is done by depressing the finger 42 to release the gear teeth and then turning the member 35 to a desired angular position of the work table. Then the finger 42 is released so that the spring 43 holds the member 35 locked. Now a fine adjustment of the angle is obtained by manipulation of the set screw 34. Then the set screws 57 and 58 are actuated to give the work table an angular adjustment in the opposite direction. Finally the nut 29 is turned to advance the work table to a proper relation to the lap I6.

It will be appreciated that the arm 30 may also be utilized for a vertical setting of the work table by manipulation of the set screw 34, and this can be further increased by changing the angular setting of the stop 32 for which purpose the set screw 33a may :be used. Accordingly the work table can be used with laps of diiferent diameters and at varying distances from the centers thereof. The lap may also be moved longitudinally of the lathe bed by moving its base I4 along the same to a desired position in which it may be locked by any well-knownmeans that need not be shown herein. The weight of the work table and its associated parts will suflice to hold the set screw 34 snugly against the stop 32, but if. required, addi-. tional means may be furnished for that purpose.

The invention is readily applicable to existing lathes by perforating the same to receive the elements I 9, 20, and 25 whereby my attachment can be mounted thereon without interference with any of the other parts of the lathe.

I claim:

A device including a support having a plurality of holes therein, a horizontal carrier including a plurality of rods slidably mounted in said holes, a frame having a plurality of :bars fixedly mounted on the rods, said bars being spaced from each other to provide a vertical opening therebetween, a screw connected to the support and passing through the bars in parallel relation to the rods, a nut on the screw fitted in said space for actuating the frame toward and away from the support, and arm fitted in said space, a pivot pin for the lower end of the arm passing through the bars, an adjusting screw for angularly setting the arm carried by the latter, the frame having a seating portion for the end of the screw, a disc mounted on the arm at the upper end thereof for angular movement in the plane of the disc, which plane is parallel to the frame, the disc having teeth along the lower edge thereof, means carried by the arm for selectively releasably engaging the teeth to set the disc, a work table mounted on the disc at the upper part thereof for angular movement about a pivot at right angles to the plane of the disc, the work table having a depending flange, a frame element connected to the disc and extending around the flange in spaced relation thereto, and set screws in the frame above and below the pivot of the work table and engaging the flange to cause angular setting movement of the work table.

HENRY H. SILVERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 467,961 Ternan Feb. 2, 1892 568,545 Phillippi Sept; 29, 1896 898,528 Thompson Sept. 15, 1908 980,654 Mason Jan, 3, 1911 1,437,620 Streh1 Dec. 5, 1922 1,963,394 Yassenofif June 19, 1934 2,329,191 Favim Sept. 14, 1943

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