US1761059A - Polishing machine - Google Patents

Description

June 3, 1930. c, VAN NORMAN ET AL 1,761,059

' EOLISHING MACHINE Filed Dec.,14, 1928 2 Sheets-Sheet 1 'INVENTOR. 7 41444, a: 6.4%.,

6. M BY A TTORN June 3, 1930. c, E, NORMAN AL ,7 1,761,059

POLISHING MACHINE 2 Sheets-Sheet 2 Filed Dec. 14, 1928 3 5 1% 5 7 M 0 F 7 00 M ENTOR.

r% ATTORNEYST/ Patented June 3, 1930 CHARLES E. VAN NORMAN AND BYRON F. STOWELL, OF SPRINGFIELD, MAS SACHU- SET'IS, ASSIGNORS TO VAN NORMAN MACHINE TOOL 00., OF SPRINGFIELD, MASSA- GEUSETTS, A CORPORATION OF MASSACHUSETTS romsnnve MACHINE Application filed December 14, 1928. Serial No. 326,010.

This invention relates to machines for sanding, polishing, or bufling surfaces. The invention is particularly directed to the production of a machine, light enough for manual use, which will produce a so-called straight line rubbing action and which will operate on either plane or curved surfaces.

The machine previously proposed for polishing varnished or lacquered surfaces have been unable to displace hand rubbing because they failed in one or both of two particulars. A machine which does not duplicate the straight line eflect given by hand rubbing, but instead operates by a generally circular motion of the rubbing surface, gives an inferior appearance to the article.-::= But even with a straight rubbing action, a success ful machine must be able to duplicate the action of hand rubbing in following either a major curvature of the article being rubbed or minor undulations of the surface which, when properl rubbed, are imperceptible to the eye. We elieve that the machine herein described is the first to produce the effect of hand rubbing in these particulars withsufficient similarity to be commercially useful where good quality work is desired. The manner in which this desirable result is attained will appear from the following description and claims.

Referring to the drawings: 7

Fig. 1 is a side elevation of a polishing machine embodying our invention;

Fig. 2 is a top plan view thereof; Fig. 3 is an enlarged section on line 3-3 of Fig. 2, showing the guides and slides removed from the housing;

Fig. 4 is a section on line 4-4 of Fig. 1; Figs. 5 and 6 are enlarged sections,-on line 5-5 of Fi 1, of one of the slides and one of the rub ing pads respectively, showing the pad disassembled from the slide; and

Fig. 7 is a longitudinal section on line 77 of Fig. 4.

The mechanism in its preferred form is supported by and partially contained within a housing 10, preferably fitted with a handle 11. Within the housing is mounted an electric motor12 having its shaft 13 fitted rotation upon a shaft 16 suitably carried by the housing,-and has rigidly secured to it a bevel gear 17. Meshing with this bevel gear is a second bevel gear 18 mounted for rotation upon a vertical shaft 19 also bearing a spur gear 21. On each side of the spur gear 21, and meshing with it, are spur gears 22 and 23 carried by vertical shafts 24 md 25 bearing at their lower ends crank disks 26 and 27. To these disks are secured pins 28 and 29 pivoted to connecting rods. 30 and 31. The other ends of these connecting rods are pivoted respectively to pins 32 and 33 attached as will be described to slides carrying the polishing pads. While, if desired, one slide only need be used, it is preferred to use two slides reciprocatin in opposition in order to balance out trou lesome vibration of the device. As these slides are identical, a description of one only will be given.

Each slide comprises as its main body a strip 35 of leather or other suitable slightly flexible material, cut away on its sides as at 36. A flexible metal strip '37, preferably of phosphor bronze, is connected to the leather strip by rivets 38. The gap at each side formed between the cut away portion 36 and the metal strip serves to receive a steel strip 39 joined by rivets 40 with a leather strip 41 lying within flanges 42 of the housing 10 and joined thereto by screws 43. The leather strip 41 and the steel strip 39, separated by spacing strips'44 preferably of fiber, form a guideway upon which the slide, comprising the leather strip 35 and the bronze strip 37, slides. The sliding friction during the re ciprocation of the slides is taken up by the bearing of the bronze and steel strips on each other. At one end of the leather strip 35 a metal plate 45 is inserted, conveniently held in place by riveting to the metal plate 37, to which the pin 32 is connected in order to join the slide with its reciprocating mechanism. The stationary leather strip 41 is slotted as at 46 to permit the necessary movement of'the pin.

The rubbing pads are preferably detachabl connected to the slides so that pads of di erent textures, pads impre ated with different abrasives, or even sanding surfaces,

may be used as desired with the same operating mechanism. The detachable connection may be made in any desired manner, but it is desirable from the standpoint of ra idity of changing pads, to employ snap asteners, preferably of a rugged type and of fairly large size. The shanks 47 of a series of these fasteners 48 pass through holes in the metal plate 37 and are headed over as at 49. The holes are made somewhat larger than the shanks in order to permit a slight amount of side play, useful in accommodating slight inaccuracies in the positioning of the fasteners on different pads and in facilitating the assembly of the pads with the slides. lhe pads are formed with a felt body 50 adherently secured to leather strips 51. The shanks 52'of snaps 53 mating with the snaps 48 pass through the leather and are headed over as at 54 before the felt bodiesare applied.

The leather strips 41 forming part of the guideways are preferably rigidly held where they are connected with the housing, but they project beyond the housing'a considerable distance to form a flexible extension of the guideway. To increase the flexibility at this point, notches 55 may be cut transversely of the strips. The extensions of the guides may be flexed to cause the similarly flexible slides to follow the contour of the object being.

polished, ribs 56 bein preferably riveted to the leather strips 41 etween grooves 55 to facilitate exerting the necessary manual pressure for this purpose.

In use the device is placed upon the work to be polished and the motor started, a switch 57 beln conveniently located in the handle 11 for t is purpose. The speed of the motor and the design of the associated gearing is such as to reciprocate the slides at a fairly 7 rapid rate. say seven hundred strokes a minute. Where more than one slide is employed, the cranks are preferably set so that the slides move simultaneously in opposite directions. This completely eliminates any troublesome tendency for the device to, jump and creep on the work, due to the balancing of the dynamic forces; and also gives to the 'device a very slight wobble from side to side which causes any point on the rubbing pad to travel in a very flat figure 8 curve rather than in a straight line. This slight sidewise movement is desirable as it prevents scratchin and causes amore even polishing action. f the work is curved, like an automobile fender, or if it possesses slight undulations, like most woodwork, the guides are curved by manualpressure upon their extended portions so that the slides carrying the rubbing pads are caused to conform to the particular shape of the surface being dealt with. The device will. operate on plane, convex, or concave surfaces with equal facility, provided the curvature is not too abrupt.

1,7e1,ose

What we claim is: v

1. A olishing machine comprising two sets of exible guideways, a pair of flexible slides one reciprocable in each guideway, rubbing surfaces carried by the slides, and means for-moving the slides simultaneously in opposits directions.

2. A olishing machine comprising two sets of exible guideways, a rigid housing supporting the guideways over a portioh of their length to avoid flexure while permitting 3. A polishing machine comprising two guideways side by side, each guideway being flexible throughout a portion only of its length, a pair of slides one reciprocable in each of theguideways' and flexible for at least a portion of their length, rubbing sur-' faces carried by the slides, and means for reciprocating the slides simultaneously in opposite directions.

'4. A polishing machine comprising a housing, guides secured to the housing and having flexible extensions projecting beyond the housing, flexible rubbing members reciprocable on the guides, a'motor in the housing, a pair of cranks rotatably mounted in the housing, gearing connecting the cranks to the motor, and connecting rods joining the cranks to the reciprocable rubbing members, the cranks being mounted in opposition so that the rubbing members are reciprocated simultaneously in opposite directions.

5. A polishing machine having a housing, a strip of leather or the like carried by the housing and projecting beyond it to form a flexible extension, flexible spacing strips secured to the edges of the leather strips, flexible metallic bearing strips secured to the spacing strips and extending inwardly therefrom,

a slide of leather or the like extending be-,

tween the spacing strips and held by the bear ing strips, a flexible metallic bearing strip secured to the leather slide and underlying the first-named bearing strips so that upward pressure on the slide is absorbed by the two sets of bearing strips, a rubbing pad detachably connected to the slide, and means'for reciprocating the slide relatively to the housface and slidable in the guideway, and meohanism for reciprocating the slide. v

8. A polishing machine comprising a flexi-' ble guideway, a rigid housing supportin the guideway over a portion of its lengt to avoid flexure While permittin flexure in the remainder of the length of tfie guideway, a flexible slide reci rocable in the guideway, and bearing a, ru bing surface, and mecha- 1o nism carried by the housing for reciprocating the slide. I Y

9. A olishing machine comprising a flexible i eway, a rigid housing supporting the gui eway over a portion of its length to avoid exure while permitting flexure in the remainder of the length of the guideway, aflexible slide reciprooable in the guideway, a flexible rubbing pad detachably carried by the flexible slide, and mechanism carried by the housing for reciprocating the-slide. In testimony whereof we have afiixed our signatures.

CHARLES E. VAN NORMAN. BYRON F. STOWELL.

Images