US2464385A - Abrading tool - Google Patents

Description

March 15, 1949.

Filed Maroh 12, 1947 J. F. ElsELE 2,464,385

ABRADING TOOL 2 Sheets-Sheet 1 Y /NVENTOR John F. Eisele FlC.

M4. @www ATTORNEY March 15, 1949.y

Filed March 12, 1947 J. F. EISELE ABRADING TooL 2 Sheets-Sheet -2 Patented Mar. 15, 1949 UNITED STATES PATENT OFFlCE ABRADING TOOL John F. Eisele, Pinckney, Mich.

Application March 12, 1947, Serial No. 734,138

10 Claims. l

This invention relates to abrading tools and more particularly to holders for sheets of abrasive material.

The principal object of the present invention is to provide a tool of the above character, means for minimizing the clogging of sheets of abrasive material when the tool is in use.

A further object of the invention is to provid such a tool which can be adjusted to conform to curved surfaces on which the tool is used.

Another object is to provide such a tool which can be easily and economically manufactured.

For a thorough understanding of the invention, reference is made to the following description and accompanying drawings, wherein:

Figure 1 is a side elevational view of a sanding tool embodying the present invention;

Figure 2 is a plan view of the base of the tool, the grip member having been removed from the tool;

Figure 3 is a cross-sectional view taken on substantially the line 3-3 of Figure 1;

Figure 4 is a side elevational View similar to Figure 1 showing the base of the tool adjusted to fit a concave surface;

Figure 5 is a bottom plan View of the base; and

Figure 6 is a side elevational view of one of the clamping strips in the base.

The tool disclosed herein is designed to hold a sheet of abrasive material, such as sandpaper, emery paper, or the like, while the tool is reciprocated by hand upon the surface being worked upon. The tool is preferably connected by a flexible hose to a source of compressed air, and the tool is so designed that when thus connected, a stream of compressed air is continuously forced out between the base of the tool and the sheet of abrasive, thereby vibrating the latter and shaking small particles from the abrasive sheet, minimizing the clogging thereof. The base of the tool is flexible, so that it can be adjusted to llt variously curved surfaces.

In general, the tool comprises a flexible base I0 on which the abrasive sheet is supported, a grip I I by which the tool may be held in the hand and by means of which the sheet of abrasive is clamped to the base, mechanism l2 for adjusting the curvature of the base, and means for introducing a stream of air between the base and the abrasive sheet.

The base I0 is formed from a plurality of relatively thin plates of metal I3 and lll, and a pad formed of a sheet oi felt I5 and a sheet of rubber I6. There are two plates of metal I3, both identical. They are generally rectangular and each is provided at one end with an upstanding flange I'l. These two flanges are located in parallel relation and clamped against opposite faces of a metal spacer I8 which will be more fully described presently. The edges of the plate I 3 remote from the flanges Il are provided with flanges I9 of arcuate cross-section. See Figures 1 and 4.

The plates Ill, of which there are two, are of approximately the same width as plates I3, but are shorter. They are placed en top of the plates I3. An edge of each plate Il?. is provided with an upstanding flange 2Q. The flanges 20 are positioned against the flanges Il, as seen in Figures 1 and 4.

The spacer I8 is a rectangular plate of metal having a hole 2| therethrough, and a slot 22 communicating with the hole and extending downwardly to the lower edge of the spacer.

The flanges I 'I and 26 are 'clamped against the spacer I8 by two metal strips 23, which are fastened in place by two machine screws 24. The strips 23 and flanges I'l and I8 all have holes therethrough registering with the hole 2I in the spacer I8. Each strip 23 is also provided with a pair of laterally spaced tongues 25 struck from the metal thereof and bent outwardly and downwardly. See Figures 1, 4 and 6. A pair of parallel slots 32 extend downwardly from the top edge of each strip 23. See Figure 6.

The felt pad I5 is cemented to the under sides of plates I3 and curves upwardly over the flanges I9. A plurality of pieces of cord or ilexible wire 25 are cemented to the bottom surface of the felt, as shown in Figure 5. The cords 26 are arranged so that they radiate outwardly from the center of the felt sheet. The rubber sheet I6 is cemented to the cords 26 and the felt I5. Since the rubber sheet i6 is thin and soft it conforms to the irregular contour of the felt and cords and produces a plurality of downwardly opening shallow channels or grooves radiating from the center of the pad. A hole 27 is cut through the rubber and felt sheets to register with the slot 22 in the spacer IB.

The/grip Il is a piece ofv relatively heavy, yet somewhat flexible metal, bent into U-shape. See Figure 1. The extremities of the grip are flanged laterally outwardly at 28. The bight of the grip is covered with a pad 29 of soft material. In the center of the bight of the grip is a downwardly opening depression 3E). See Figure 3.

The grip is employed as a handle to be grasped by the operator of the tool. It is also used'to clamp a sheet of abrasive material 3l onto the base. The sheet of abrasive is out sufficiently long the slot 22 in the part i8.

to cover the under side of the base and curve over the ends of the base into the channels formed by the curved anges I9. The legs oi the grip i l are then sprung into the channels, with the flanges 23 engaging the abrasive and clamping the same against the insides cf the iianges lil.

The mechanism l2 for adjusting the curvature of the base comprises a pair of parallel arms rlhe arms 33 are attached to a pair oi thin flexible metalplatesjl of the configuration shown in Figure'Z. The arms are pivotally connected to upturned ears 35 on opposite sides of the plates M. The central portions of the arms are connected together by a bolt 3i? and a spacing sleeve 31. Rigidly attached to the spacing sleeve 3l and extending radially thereof is a screw 3S.

A relatively deep rectangular notchs is cut in each arm midway between its ends. The notches receive the anges il and 2t and the spacer I8. The edges of the notches 39 fit into and slide vertically in the slots 32 in the clamping strips23.

`Two coil springs 40 havingeyes lll in the ends thereof are hooked onto the lugs 25 on the strips p23 and extend over the spacing sleeve 31. The

3B. The adjusting nuthas an elongated sleeve et,

internally threaded at its lower end, screwed thereon. The upper end of the sleevefl is rounded to t into the depression Preferably a large knurled knob lle is xedly connected to the sleeve 43. Theknob #i4 has an annular iiange Ellla'held between the nut 42 and the sleeve 4E. The free end of the screw 38 is enlarged slightly after the -nut 42 is threaded thereon to prevent removal of the latter.

A tubular couplingll having a port .te in the side thereof is inserted into the hole El through the parts 'l, lfll andf, and securely fastened therein. /The port it is arranged to register with One end of the tubular coupling is closed by a suitable plug. To the other ends of the coupling is attached an air hose 4'1 f above, the valve in the air line opened. The

tool is then applied to the surface `to be sanded and vmanually reciprocated thereon, as in the case of the well known crude sandpaper block. A stream of air under `pressure liows through the hose il ,and coupling't, out through theport 45, slot` 22 and hole-2l. The air cannot passthrough the` sheet of abrasive material. Therefore, it fans outwardly between the rubber sheet i6 andthe abrasive through the shallow grooves between the ridges in the rubber sheet formed by the cords 25. In so doing it sets ip a rapid Vibration, or fluttering, of little magnitude in the abrasive sheet, ythereby dislodging particles of dust abraded from the work surface, which ordinarily tend to ll the spaces between the abrasive particles on the sheet of abrasive material.

If the work surface is concave, the base can be See Figure transmitted through the arms 33 to the plates 34 between the center and the ends oi the base. The force is distributed quite uniformly through the plates 35i and thereby produces a smooth, uniform curve in the base. The arms 33 can slide np and down relative to the central rib formed of the parts ll, Eil, 2li and 23, upward movement of the arms being resisted by the springs Mi.

Ii the Werl; surface is convex, the knob 4d is retracted sdfciently to release the sleeve 43 from the depression and the lrnob'i, sleeve i3 and screw i@ are swung to one side, as shown in broken lines in Figure l. Since the base is flexible it can then iollow a convex surface merely by Yapplying downward pressure on the grip l l.

From the foregoing' it will be seen that the 4present invention nrotfides an abra-ding tool which be quickly adjusted to fit a plane or Various curved su Aare". It prolonge the life of the sheets oi abrasive material by minimising clogging thereof. 4It can be simply and economically nlanni'act'ln'ed.

The scope ci the invention is indicated in the appended claires.

claim:

l. A device of the character described comprising a relatively thin, flexible sheet metal base haring a central transversely extending upstanding rib, said rib having an air duct therein 1';- tending through the lower surface of ,said base centrally thereof, and means attached to said rib and associated with said air duct for forcing a current of vair through said duct out beneath said base.

2. A device oi' the character described in claim l wherein the lower surface oi the case is `provided d dcf-"yz-Lrdly opening grooves radiating toward the edges of said base from the lower end ci said air duct.

3. A device of the character described comprising a relatively thin flexible base member, an arched relativehT id grip member attached to said base member in spaced zonesfadjacent two opposite edges oi said base member and spaced from said base member intermediate said Zones, a relatively rigid extending between said Zones and engaging said base member at led points spaced from scnes, spring means con necting said arms to said base intermediate the ends ci said arm and biasing said arm toward said base member, and an extensible and contractible strut connected to said arm intermediate the ends of the latter and engaging said arched grip member centrally thereof.

e. A device of the character described in claim 3 wherein said strut is pivotally connected to said arm and is disengageable from said arched grip member when said strut is contracted a predetermined distance.

5. A device of the character described comprising a relatively thin flexible base member, a relatively rigid arched grip member attached, to said base member in spaced sones adjacent two opposite edges oi said base member and spaced from `said be e intermediate said sones, a pair apart relatively arms eX- tending between said zones and engaging said base member at spaced points spaced from said Zones, and an extensible strut connected to said arms intermediate the ends of the latter and engaging said arched grip member centrally thereof.

6. A device of the character described in claim 5 wherein said strut is pivotally connected to said arms and is disengageable from said arched grip member when said strut is contracted a predetermined distance.

7. A device of the character described in claim wherein said strut comprises two parts connected together and movable axially of each other.

8. A device of the character described in claim 5 wherein said arms are connected to said base member by spring means attached to said arms and said base member intermediate the ends thereof, said spring means normally biasing said arms toward said base.

9. A device of the character described comprising a relatively thin exible base member, an arched relatively rigid grip member attached to said base member in spaced zones adjacent two opposite edges of said base member and spaced from said base member intermediate said zones, a relatively rigid arm extending between said zones and engaging said base member at spaced apart points spaced from said zones, and a strut connected to said arm intermediate the ends of the latter and engaging said arched grip member centrally thereof, said strut being extensible and contractible whereby to vary the spacing of the central portions of the base member and grip member and thereby iiex said base member.

10. A device of the character described in claim 6 9 wherein said strut is pivotally connected to said arm and is disengageable from said arched grip member when said strut is contracted a predetermined distance.

JOHN F. EISELE.

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

UNITED STATES PATENTS Number Name Date 222,268 Gilmore Dec. 2, 1879 271,222 Coffin Jan. 30, 1883 736,736 Kane Aug. 18, 1903 812,119 Denson Feb. 6, 1906 840,982 Williams Jan. 8, 1907 1,009,785 Peterson Nov. 28, 1911 1,501,192 Severns July 15, 1924 FOREIGN PATENTS Number Country Date 576 Great Britain J an. 8, 1912 438,824 France Mar. 25, 1912 350,391 Germany Mar. 20, 1922 523,147 Germany June 1, 1929 582,349 Germany Aug. 14, 1933 Certificate of Correction Patent No. 2,464,385. March 15, 1949. JOHN F. EISELE It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 5, after the Word provide insert in; column 3 line 47, for ends read end;

and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the oase n the Patent Office.

Signed and sealed this 23rd day of August, A. D. 1949.

[IML] THOMAS F. MURPHY,

Assistant Commissioner 0f Patents.

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