US2125742A

US2125742A - Abrasive disk

Info

Publication number: US2125742A
Application number: US102736A
Authority: US
Inventors: Herman O Sundhauss
Original assignee: JOSEPH L EISENDRATH JR
Current assignee: JOSEPH L EISENDRATH JR
Priority date: 1936-09-26
Filing date: 1936-09-26
Publication date: 1938-08-02
Anticipated expiration: 1955-08-02

Description

- ug. 2, '1938. H. o suDHAuss ABRAsIvE nIsx Filed sept. 26. 193s Patented Aug. 2,. 1938 PATENT oFI-ICE .ABRASIVE DISK Herman 0. Sundhauss, Chicago, lll., assigner to JoseplrL. Eisendrath, Jr., Chicago, Ill.

Application September 26, 1936, Serial No. 102,736

2 Claims.

coating or facing of grit particles on its outer face, v

and has a hole in the central portion for receivlng the centering hub of the head and also has lo a pair of diametrically opposite slots which radiate from the hole and are adapted to receive and interlock with the locking wings and form a driving connection between the head and backing piece.

Heretofore it has been customary in the fabrication of a disk of this type to make the wing receiving slots of uniform width from end to end. In practice it. has been found that an abrasive disk having slots of this character is defective or objectionable for two reasons. In the rst place it is extremely diiiicult to mount the disk due to the fact that `the portions of the backing piece which dene the slots are so inflexible or stiff that they cannot readily be ilexed or dis- `torted in order to permit of entry of the'locking wings of the head into the slots. Secondly, rupture or tearing of the backing piece is likely to occur at the outer ends of the slots in connection with a disk mounting operation due to the of th' diametrically opposite wing receiving sl'ots comparatively large. .circular holes which serve to free or disconnect the ends ofthe slot defining portions of the backing piece from the portions adjacent to the ends of the slots with the result that such slot deiining portions can readily be flexed or distorted in connection with a disk mounting operation and when: flexed or distorted suiiiciently to permit of entry of the wings into the slots do rnot place tearing strain uponthe portions of the backing piece adjacent to the ends of the slots. Y

Another 'object of the invention is to provide an abrasive disk of the aforementioned type in which the diametrically opposite wing receiving yslots 5 with the comparatively large holes at the outer ends thereof are arranged or positioned so that they extend at substantially right angles to the grain of the backing piece. I

A further object of the invention is to provide 1o an abrasive strip which is generally of new and improvedconstruction.

Other objects of theinvention and the variousj advantages and characteristics of the present abrasive disk will be apparent from a considera- 15 tion ofthe following detailed description.

The invention consists in the severeal novel features which are hereinafter set forth and are` more particularly dened by claims at the conclu'sion hereof.

In the drawing which accompanies and forms a part of this specification or disclosure and in which like numerals of reference denote corresponding'parts throughout the several views:

Figure 1 is a bottom view of an abrasive .disk

embodying the invention;

Figure 2 is a plan view 'showing the disk mounted on a rotary head;

Figure 3 is a sectional view taken on the line 3 3 of Figure 2 and showing in detail the manner in' which the wings on the rotary head interlock with the diametrically opposite slots in the disk in order to form a driving connection between the head and the disk;

0f Figure 2;

Figure 5 is a perspective showing the manner in. which the holes at the outer ends of the wing receiving slots free the outer ends of the slot defining portionsof the backing piece of the disk 40 so that such portions may be readily flexed in connection with mounting of the disk and when flexed suiciently to permit of entry of the wings of the rotary head do not impart tearing strain to the portions of the disk at the ends of the slots; 45 and Figure 6 is an enlarged section showing the extent to which it is necessary to flex or distort the slot dening portions of the backing piece in order to permit the wings to pass therebetween 50 in connection withmounting of the disk on the head.

The abrasive disk which forms the subject matter of the invention is essentially a surfacing element. It is adapted for use with a rotary head Figure 4 'isa sectional view on the line 4 4 35 H and consists of a circular backing piece 'l with a coating 8 of grit particles on the outer or top face thereof. The rotary head H is shown. in the drawing as being of conventional design and has on the front end thereof a centering hub h and a pair of wings hil. It is adapted to be moved over the work as well understood in the art and is driven by an electric motor (not shown) through the medium of a flexible shaft h. The latter extends through a sheath h3 and embodies a driving element h4 which fits within av socket h5 in the central portion of the rotary head H and is drivably connected to the head by means of a 'screw thread connection h. The hub h is formed as an integral part of the head. It is centrally positioned with respect to the head and is circular, as shown in Figure 3., The wings h1 of the head are positioned on opposite sides of the hub h, and project in opposite directions. The base portions of the wings extend radially outward from the hub and are' anchored inv any suitable manner on the head. The outer portions of the wings h1' are spaced-a small distance from the outer face of the head H and extend in a circumferential manner and in substantially parallel relation with the outer face of the head. A ring h" of rubber or like material is fixed to the front face of the head and surrounds the wings h1. It -forms part of the head and serves as a backing member for the disk.

The backing piece 1 is adapted when the disk is mounted on the head H, as hereinafter described, to fit against the front faces of the head H and the ring h". It is formed of processed o r chemically treated paper and has the coating I of grit particles'secured to its front face by means of a film 9 of cement. As shown in the drawing the backing plate is slightly larger in diameter than the ring h" of the rotary head H. The backing piece although comparatively thin is comparatively stii! due to its processing or chemical treatment and the fact that the'coating 8 of grit particles is substantially rigid in characer due to embedment of the particles yin gli scementitious material which forms the The disk has a holel Il in the center thereof' mounted on the head H. The slots Il radiate from the hub-receiving hole 'I0 in the center of the disk and are adapted to receive the wings h1 of the rotary head H and form a driving connec.

tion between the head and the disk. They intersect the hole Il and are arranged so that they extend transversely of the grain of the/backing piece 1. In connection with the mounting of the disk on the head H it is necessary to flex or distort the slot defining portions of the disk a sumcient distance to permit of entry of the wings h1 into the slots. The holes i2 at the outer ends of the slots serve to free the outer ends of the slot dening portions of the disk so that such portions can readily be flexed or distorted. Preferably the holes are formed so that the diamevends of the slots that they may be flexed or distorted sufiiciently to permit of ready entry of thel wings hl into the slots without imparting tear ing strain or causing. rupture of the disk outwardly from the outer ends of the slots. The holes l2 constitute the outer ends of the slots and, as shown in Figure 2, receive the outer portions of the base parts of the wings h1.

In applying the disk to the head H the portions the sides of the other slot i iA are deflected one upwards and the other downwards and the disk is manipulated so as to bring the other wing hl therebetween. After manipulating the disk in this manner it is turned or rotated relatively to thehead so as to bring the centering hub h and the base parts of the wings h1 into seated relation with the hole I0 and the slots Il respectively. By reason of the fact that the slots Il extend crosswise of and are at substantially right angles to the grain. of the backing piece 1 and the holes I2 are of the diameter hereinbefore specified, there is little if. any likelihood ofthe portions of the disk which are disposed outwardly of the holes i2 being ruptured or torn during flexure of the slot defining portions of the disk in connection with mounting of the disk on the rotary head I. l

The herein described disk due to thefact that it includes at the outer ends of the slots Il the holes I2 whereby the outer ends of the slot defining portions of the disk are freed or severed from the portions of the disk at the ends of the slots, may be readily mounted and is extremely durable. lin orderl to reduce the cost of manufacture. the hole il, the slots Il, and the holes I2 are formed in the central portion of the disk by'a single cutting operation.

`'111e invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having' thus described the invention, whatv 1 claim as new and desire to secure by Letters Patent is:

1. As a new article of manufacture, an abrasive disk in the form of a comparatively stiff backing piece with a coating of grit particles on one face thereof and adapted to be mounted on a rotary head having a centering hub and a piurality of oppositely facing wings positioned adjacent to the sides of the hub and extending outwardly and substantially parallel to thel front face of the head, said disk having a hole in the central portion thereof for receivingthe 'centering hub of the head and a plurality of. slots extending outwardly from the hole and adapted to receive and interlock with the locking wings, and also having comparatively large holes at the outer ends of the slots serving to free or sever the outer Vends of the slot forming portions of the disk and to permit such portions to be flexed or distorted out of the plane of the disk and without causing the disk to rupture or crack at the outer ends of the slots in connection with insertion of the wings into the slots during disk mounting.

2. As a new article of manufacture, an abrasive disk in theform of a backing piece of comparatively sti paper with a coating of grit particles on one face thereof and adapted to be mounted on a rotary headfhaving a centering hub and a pair of oppositely facing locking wings radiating from opposite sides of the hub and extending outwardly and substantially parallelfwith the front face of the head, said disk having a hole in the central .portion thereof for receiving the centering hub of the head and a pair of diametrically opposite slots extending radially from the hole and transversely of the grain of the backing piece and adapted to receive and interlock with -the locking wings, and also having comparatively large holes at the outer ends of the slots serving to free or sever the outer ends of theslotvforming portions of. the disk and to permit such portions `to be exed or distorted out of the piane of the disk and without causing the disk to rupture or crack at the outer ends of the slots in'connection with insertion of the wings into theslots during disk mounting.

HERMAN 0. SUNDHAUSS.