US2124042A - Protecting hood - Google Patents

Description

.July 19, 1938. w. R. SHIELDS I 2,124,042

PROTECTING noon Filed July 51, 1937 INVENTOR WILLIAM RSHIELDS ATTORNEYS Patented July 19, 1938 UNETED STATES PATENT OFFECE Hit-Production Wheel Corporation,

Detroit,

Mich, a corporation of Michigan Application July 31, 1937, Serial No. 156,788

3 Claims.

This invention relates generally to abrading apparatus and refers more particularly to improvement in machine operated abrading apparatus.

It is an object of the invention to provide a rotary abrading apparatus in combination with a shield formed of soft resilient material and supported by a stationary part of the apparatus.

It is a further object of the invention to provide a shield for a high speed wet type abrader in which the abrading element is specially formed to cooperate with a specially designed shield so as to prevent radial throwing off of liquid by the contrifugal action of the abrading element.

It is a further object of the invention to pro- -vide a soft resilient shield in an abrading apparatus which is reinforced to impart rigidity to the shield.

The foregoing, as well as other objects, will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein Fig. 1 is a side elevation of the device with a portion of the shield broken away;

Fig. 2 is a side elevation of the shield element partially in section, and

Fig. 3 is a top view of my improved shield.

The device as a whole includes a rotary abrading element Ill which is secured to and rotatably driven from a stationary element 20. The shield 3|) is attached to the stationary element 20.

The rotary body It) comprising the abrading element is made up of two disk shaped pads, a rear pad l2 and a front pad These pads are provided with forward faces of soft gum rubber and rear faces of relatively hard composition rubber and fabric. The forward working pad II is slightly dished on its forward face to provide a concave surface and in this concave surface is positioned a soft double convex filler pad (not shown) made of gum rubber. A sheet of abrading material it is stretched over the forward face of the pad I I and tabs l4 extend around this pad and engage suitable securing means on the rear surface thereof. These securing means are received in a groove (not shown) in the forward face of the rear pad I2. The rear pad l2, the forward pad H, the filler pad (not shown) and the sheet of abrading material are centrally apertured as at Hi to provide a passage for liquid to be used in the finishing operation, the passage l6 extending axially of the drive shaft 25.

A stationary element 20 is provided and has a gear box 2| in which are provided suitable reduction gearing, if desired, through which the rotary abrading element In is driven. A flexible conduit 26 is connected tothe gear box 2| and through this conduit extends a flexible drive shaft (not shown) which connects to suitable power source. The gear box 2| also has a connection 22 to which is secured a flexible passage 23 leading to a source of suitable liquid supply such as water. A valve 24 is provided in the connection whereby the abrading device may be used either with water supplied to the working surface thereof or dry.

The abrading device disclosed herein is adapted to be driven at relatively high speeds on the order of 1100 R. P. M. for certain surfaces. The device is capable of numerous applications and may be used to finish surfaces which are unfinished, finished or painted. It may be used for polishing instead of abrading by replacing the sheet of abrading material with a sheet of felt, sheepskin, canvas or the like. It is well adapted for finishing the surfaces of automobile bodies. It has been found that when operating this device at the relatively high speed mentioned, if the rotary body is inadvertently brought in,contact with a projection on the surface being finished, such for example as hinge on an automobile body, there is a strong likelihood that the projection will tear the sheet of abrading or finishing material or will damage the relatively soft material of the pads H or l2. It has also been found that when the device is being used with Water supplied to the working surface through the central conduit it that due to the centrifugalv action the water is thrown oif radially, causing discomfort to the operator and other undesirable results which will be obvious.

I have therefore provided a shield 3|] which is secured to the stationary or handle portion 20 of the abrading device and which extends in spaced relation about the rotary abrading element ID. This shield is preferably formed of a soft material such for example as rubber. The forward edge of the shield element 30 terminates a short distance rearwardly of the forward face of the rotary abrading element Ill. The rotary abrading element In as described above is relatively soft on its forward working face, so that it may conform to irregularities in curvature in the surface being finished. The forward edge of the shield element 30 is spaced rearwardly from the forward working face sufficiently so that it will not interfere with desirable deformation of the forward working surface.

It should be particularly noted that the forward face of the abrading element I0 is provided with outer curved edges IT. The relationship between the curved edges l1 and the forward edge of the shield element 30 is such that the curvature of the edges I'I extends well within the confines of the shield element 30 for a purpose which will later appear.

The shield element 30 has a cylindrical collar portion 3| adapted to fit the cylindrical portion of the gear box 2| in tight gripping relationship. This collar forms the sole support for the shield, the balance of the shield being spaced from the rotary abrading element 56. From the forward edge of the collar 3i the shield extends outwardly, presenting a fiat annular portion 3 I and from the outer edge of the flat annular portion 3W, the shield extends forwardly presenting a cylindrical portion 32. A bead 33 is formed peripherally about the forward edge of the shield, and suitable reinforcing means such as a wire 34 is imbedded in the bead to impart stiffness thereto. If desired, in order to increase the rigidity of the shield as a whole, suitable ribs 35 may be provided extending radially outward on the flat annular portion 3H and axially forward on the cylindrical portion 32 to the bead 33.

In operation, the soft resilient shield 30 serves three functions. In the first place, it prevents the rotary element 10 from coming in contact with and damaging projections on the surface being finished. Secondly, the shield protects the rotary element I!) from being damaged by projections on the working surface, which is especially necessary in the present apparatus due to the relatively high speed to which it is employed. Thirdly, the shield prevents liquid and abrading material being thrown off radially due to the centrifugal action of the high speed abrading element.

As was pointed out above, the abrading element ID has a rearwardly curved forward working surface IT. This curving surface I! extends back into the confines of the shield 30. The result of this is that as liquid and abrading material are thrown outwardly by centrifugal action, they follow the curvature I! for a certain distance and the major portion thereof is therefore thrown off within the confines of the shield 30. The particular cooperation between the specific form of abrading element and the shield forms one aspect of the present invention.

While I have disclosed my shield element 30 as made of soft resilient material such as rubber, it should be apparent that it may be made of other material while retaining numerous of its many advantages.

What I claim as my invention is:

1. In a device of the character described, a handle portion, a rotary body secured to said handle portion, said body having a forward face to be engaged with a surface to be finished, means for supplying liquid to the forward face of said body, a shield having a collar engaging said handle portion and supporting said shield, said shield extending outwardly and forwardly from said collar in spaced relation to said rotary body and terminating in a forward edge spaced slightly rearwardly of the forward face of said rotary body, the'forward face of said rotary body having edges rounded to throw off liquid radially outward within the confines of said shield.

2. A device of the class described comprising a circular body having a forward working face provided with rearwardly curved outer edges, a rotary driving member for said body, a housing for said driving member, means carried by the housing for supplying a liquid to the working face of the rotary body, and a cup-like shield encircling the rotary body, said shield being fixed to the housing, the forward edge of the cup-like shield terminating just in rear of the forward working face of the body, and the curvature of the outer edges of the body extending well within the confines of the cup-shaped shield so that the major portion of the liquid thrown outward- 1y by centrifugal action when the body is rotated will be within the confines of and intercepted by the shield.

3. A device of the class described comprising a rotary body having a forward working face provided with rearwardly curved outer edges, a rotary driving member for said body, a housing for said driving member constituting a handle, means carried by the housing for supplying a liquid to the working face of the rotary body, and a shield of resilient material encircling the rotary body and having a collar sleeved upon the housing, the forward edge of the shield terminating just in rear of the forward working face of the body, and the curvature of the outer edges of the body extending well within the confines of the shield so that the major portion of the liquid thrown outwardly by centrifugal action when the body is rotated will be within the confines of and intercepted by said shield.

WILLIAM R. SHIELDS.

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