US2439751A

US2439751A - Abrasive disc holder

Info

Publication number: US2439751A
Application number: US683523A
Authority: US
Inventors: Gustav A Olsen
Original assignee: Albertson and Co Inc
Current assignee: Albertson and Co Inc
Priority date: 1946-07-13
Filing date: 1946-07-13
Publication date: 1948-04-13
Anticipated expiration: 1965-04-13

Description

April 13, w48.` G. A. QLSEN I 2,439,751

ABnAsIvE DIscv HOLDER Filed July 13,1946

I ff

IN VEN TOR. @a mfaww Patented Apr. 13, 1948 UNITED STATES PATENT OFFICE ABRASIVE DISC IHOLIERl Gustav A, Cisen, Sioux City, Iowa,` assignor to Albertson & Company, Inc., Sioux City, Iowa.

a corporation of Iowa Application July 13, 1346, serial No. 683,523

6 Claims. (Cl. 51-197) This invention relates to abrasive disc h'olders of the kind widely employed by automobile body finishers and others for smoothing rough surfaces; and it has to do more especially with an improvement in the type of abrasive disc holder described in United States Patent 2,132,917, granted to F. O. Albertson October 11, 1938.

In the holder of the Albertson patent the abrasive disc is secured against a resilient hard rubber pad which affords a certain amount of ilexibility at and near the periphery of the discwhich flexibility is very essential to good results, but is not adapted to cushion shock components transmitted through the disc in the plane of rotation.

My object is to improve the performance characteristics of abrasive disc holders, such as that described in the Albertson patent, to the end of achieving smoother operation and reduction of shock, and, by so doing, to provide an equipment which will turn out a better job and, generally, with concomitant saving of time.

, I have found that the above-stated object substantially can be realized by incorporating in the hub of the disc holder suitable resilient means which serve to introduce a limited yieldability near the axis of rotation, both in the plane of rotation and all planes normal thereto, with the result that the abrasive disc is better able to cope with unusually irregular surface conditions.

In the drawing which accompanies this specication:

Fig. 1 is a side elevational view of a sanding machine including a disc holder embodying the subject improvement;

Fig. 2 is a top plan view, partly in section, of the improved disc holder, on a larger scale th'an Fig. 11

Fig. 3 is a. sectional view of the disc holder taken along the plane of the axis of rotation thereof; and

Fig. 4 is an enlarged detail view depicting the 2 Ita is indicated fabric reenforcement for the ring or table I6.

Hub I4 includes a cup-shaped member 20 hav-A ing an outwardly directed flange 2| and carries an internally threaded sleeve 22 by means of which the holder can be detachably connected to drive-shaft Il of the machine. Sleeve 22 may be brazed, Welded or otherwise firmly secured to member 20 or it may be cast or forged integrally therewith, Hub I4 also includes a driven member 23 disposed in co-axial alignment with member 20 and having an external flange 24. A depending threaded stud 25 is brazed or otherwise novel construction by which the desired hub flexibility is achieved.

Referring to Fig. 1, the sanding machine there shown is a portable tool comprising a motor I0 having a suitable built-in right angle transmission including a drive-shaft I I to which the abrasive dlsc holder I2 is detachably connected-the drive-shaft being provided with a threaded end for that purpose.

The holder I2 with attached abrasive disc I3 is shown in detail in Figs. 2-4 inclusive.

The major components of the disc holder are a hub I4, an annular disc I5 carried by the hub and concentric therewith, a molded hard rubber ring I6 generally referred to as a pad, a pair of superposed backing discs I1 and I8, 'and a flanged nut lIii which serves to secure the abrasive disc I3 and backing discs I1, IB to the holder. At

ilrmly attached to. member 23 in axial alignment with sleeve 22 and form a part of the hub. Nut I9 is threaded onto stud 25 and has a thin slightly convexed head or iiange I9a which bears against the face of abrasive disc I3. The abrasive disc, together with backing plates I1, I8, are detachable from the holder by removing nut I9 from stud 25.

Flange 2| of member 2|l conveniently is provided `with six equally spaced holes 26 located on a circle concentrically'with the axis of' rotation of the hub, and in these are rigidly secured, as by riveting, six pins 21.

Flange 24 of member 23 is similarly provided with six equally spaced holes 28 which are in registration, individually, with pins 21 and of substantially larger diameter than the pins so that member 23 can rotate slightly relatively to the pins and to member 20.

Likewise, annular disc I5 is provided with six holes by means of which it is firmly mounted on pins 21 concentrically with the axis of rotation of the holder.l The periphery of disc I5 is embedded in pad I6 and maintains the latter in concentric relation to the hub. Disc I5 also serves to centralize hub member 23.

As shown most clearly in Figs. 3 and 4, there is interposed between flange 2| and ilange 24 a resilient spacer in the form of a gasket or washer 29, preferably of neoprene or other soft rubberlike material; and similarly linterposed between flange 24 and disc |5` is a second resilient spacer in the form of a gasket or washer 30 which also is made of material such las neoprene The

assembly comprising washers

29 and 30, iianges 2| and 24, and disc I5 are secured together because the headed end of each pin bears against a metal washer or ring 3|. The riveting of pins 21, being performed at the shouldered ends thereof, does not unduly compress the parts which such pins hold in assembly.

Spacers

29 and 30 may, alternatively, consist each of 'a single annulus or of several washers individual to pins 21. s'

Driving power is transmitted from driving member 20 through' pins 21, thence through

resilient spacers

29, 30 to the driven member 23, and

thence via stud 25 and nut I9 to abrasive disc I3 and backing plates Il, I8. The central openings in the abrasive disc and backing plates are non-circular and preferably hexagonal, and the shank of nut I9 is ci corresponding form to fit said openings whereby to provide a positive driving connection to the abrasive disc.

The resiliency afforded by

spacers

29 and 30 permits the abrasive disc to yield to a limited extent to any extra hard spots which may be encountered in the surface being worked upon, such for example as weld seams, and this not only reduces the amount of shock felt by the operator but it also has been found definitely to result in superior workmanship-which probably is attributable to the workman being better able to steady the machine against shock-producing .conditions and to minimized nervous strain.

Whatever the correct explanation may be, the fact remains that workmen express a distinct preference for disc holders constructed in accordance with the present invention, and it is a demonstrated fact that, on the whole, they do distinctly better work with disc holders so equipped. Equipment comprising my improved abrasive disc-holder is especially adapted to do fine work when feathering the edges of surface coatings of metal finishing enamel and the like.

Having thus illustrated and described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In an abrasive disc holder, a hub comprising a rst hub member having an outwardly projecting flange, a second hub member co-axial with said rst hub member and havingan outwardly projecting flange in face-to-face relation to the f first-mentioned flange, a plurality of spaced pins rigidly attached to one of said flanges and each passing loosely through an opening in the other of said flanges, a cushion ofresilient material clamped between and separating said nanges and operating as the torque transmitting medium between said hub members, andmeans for attaching an abrasivedisc to said second hub member. l

2. In an abrasive disc holder, a hub comprising a driving member and a driven member co-axial therewith, said membersy having complementary flanges, a plurality of parallel pins rigidly connected to one of said flanges and extending loosely through the other flange, a resilient spacer between said flanges and functioning as a torque transmitting medium between said members, said pins serving to Vclamp said iianges against said spacer, and means for detachably connecting an abrasive disc to said driven member co-axlally with said hub.

3. In an abrasive disc holder; a hub comprising a driving member and a driven member coaxial therewith,a plurality of spaced pins rigidly connected to one of said members and disposed around the axis of rotation of said hub and extending parallel to said axis, an annular disc mounted on said pins concentrically with said hub and projecting outwardly therefrom, an annular pad carried by said disc, said driven member having a flange interposed between said driving member and said disc, a first resilient cushioning means interposed between said driving member and said flange, a second resilient cushioningmeans interposed between said disc and said flange, said rst and second cushioning means and said flange being clamped by said pins between said driving member and said disc, and means for detachably connecting an abrasive disc to said driven member co-axially with said hub.

4. In an abrasive disc holder, a hub comprising a cup-shaped driving member adapted for attachment to a drive-shaft and having an external flange concentric with its axis of rotation, a plurality of pins secured to said flange and circumferentially spaced in a circle concentric with the axis of rotation of the hub, said pins extending parallel to said axis, an annular disc carried by said pins and extending outwardly therefrom radially to the hub, a driven member forming a part of said hub and having an external fl e interposed between the first-mentioned ila e and said disc, resilient spacing means interpos d Ibetween said flanges and embracing said pins, additional resilient spacing means interposed between said disc and the flange of said driven member and embracing said pins, thev last-mentioned flange being normally out of contact with said pins, said driven member being adapted to rotate to a limited extent relatively to said driving member due to the yieldability of said spacing means, said driving and driven members and said disc and spacing means being clamped together by said pins, a threaded stud carried by said driven member co-axially therewith, and a flanged nut co-operative with said stud for detachably securing an abrasive disc to the holder.

5. In an abrasive disc supporting device, a first liub member and a second hu'b member, the iirst hub member being adapted to be mechanically connected with a motor for rotation thereby, an abrasive disc table associated with the second hub member and capable of limited axial movement relative thereto but incapable of radial movement relative thereto, the two hub members being provided with opposed annular surfaces occupying planes transverse to the rotational axis of the first hub member, the table and the second hub member being provided with opposed annular surfaces occupying planes transverse to said rotational axis, annular cushions of relatively soft yielding material interposed between the opposed surfaces of the hub members and between the opposed surfaces of the table and the second hub member, a plurality of pins by which the Afirst hub member is connected with the table, and a plurality of apertures in the second hub member through which such pins freely extend with substantial clearance.

6. In an abrasive disc holder a hub comprising a driving member and a driven member co-axial therewith, a plurality of parallel pins rigidly connected to one of said members and extending loosely through the other member, a resilient spacer between said driving member and said driven member and functioning as a torque transmitting medium between said members, said pins serving to clamp said driving and driven members against said spacer, and means for detachably connecting an abrasive disc to said driven member coaxially withsaid hub.

GUSTAV A. OLSEN' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,835,573 Ponselle Dec. 8, 1931 1,933,846 Finnell Nov. 7, 1933 FOREIGN PATENTS Number Country Y Date 652,171 ,Germany Oct. 26, 1937