Sanding Block And Abrasive Envelope Therefor

Abstract

Presented are two embodiments of a sanding block adapted to be inserted within an abrasive envelope configured to fit snugly around the block. The block and envelope assembly are configured to expose an optimum amount of abrasive surface to a surface to be smoothed. The block of one embodiment is preferably fabricated from a dense but flexible and resilient material which permits conformation of the abrasive surface of the assembly to a surface to be abraded, while the block of the second embodiment is preferably wedged, fabricated from a sponge-like material such as sponge rubber or polyurethane foam-type material, and beveled along lateral edges to provide a dual wedged configuration.

Parent Case Text

BACKGROUND OF INVENTION

This application is a continuation - in-part of co-pending application Ser. No. 59,377, filed July 30, 1970 by the inventor herein.

Description

It is generally known that painters and other workmen employed to refinish or repaint surfaces carry with them pieces of abrasive-coated cloth or paper which they can grasp with the fingers and rub over a surface required to be smoothed. Because such abrasive coated material is relatively flexible and flimsy, the only surface thereof that normally abrades the surface being smoothed is the rather minimal surfaces disposed beneath the fingertips. This concentration of pressure on a relatively small area of the abrasive material causes appreciable wear at these points, resulting in the abrasive material being torn and therefore unsuitable for further use in a much shorter time than is necessary. It is one of the objects of the invention in one of its aspects to provide an easily portable combination sanding block and abrasive envelope assembly which utilizes the inherent flexibility and resilience of a deformable sanding block fitted within a flexible envelope of abrasive material to expose an optimum amount of abrasive surface to a surface being smoothed.

In the prior art, it is common to find various types of devices upon which a piece of abrasive paper or cloth may be mounted. Most such devices are bulky and cumbersome to use and store and do not permit exposure of all of the abrasive surface, thus contributing to waste. Accordingly, it is another object of the invention to provide a sanding block and abrasive envelope therefor in which all surfaces of the abrasive envelope may be utilized to perform a smoothing function.

Conventionally, painters or other workers required to use an abrasive material such as "sandpaper" buy full sheets, which are generally larger than can conveniently be used. It is customary to cut such sheets into smaller portions for attachment to a holding frame. The necessity of folding and carefully cutting such sheets prior to use is time consuming and costly and it is, accordingly, another object of one aspect of the invention to provide as an article of manufacture a flexible envelope having abrasive surfaces and adapted to receive a flexible and resilient sanding block configured to compliment the interior of the abrasive envelope.

A still further object of the invention is the provision, as an article of manufacture, of an abrasive envelope configured to nest with other similar abrasive envelopes to facilitate packing and shipping.

A still further object of the invention is to provide as an article of manufacture a flexible envelope having abrasive surfaces and lateral edges secured together along marginal portions to form a pocket in which to receive a dualwedged sanding block formed from a resiliently deformable and compressible material such as sponge rubber or polyurethane foam.

BRIEF SUMMARY OF INVENTION

In terms of broad inclusion, in the aspects chosen for illustration, the invention comprises a flexible and resilient single or dual wedge-shaped block having flat sides tapering to a relatively sharp edge along one long side and conveniently fabricated from a dense sponge-like synthetic resinous or natural material such as rubber. In one embodiment the lateral edges of the block defining the limits of the flat sides are beveled to provide a sharp lateral edge. The flexible and resilient single wedge-shaped block is adapted to fit into the hollow interior of an envelope having a configuration complimentary to the single wedge-shaped block, while the dual wedge-shaped block is adapted to slip into an envelope formed merely by doubling a strip of abrasive paper longitudionally and cementing the lateral edges. The outside surfaces of both types of envelope are coated to provide abrasive surfaces similar to the abrasive surface of emery cloth or abrasive paper. In one aspect of the invention, and as an article of manufacture and sale, a number of envelopes, say a half dozen, together with one of the flexible and resilient single wedge-shaped blocks, are packaged for sale. Thereafter, it is necessary for a user merely to buy additional abrasive envelopes in whatever quantity it is convenient for the particular user.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating one embodiment of the block and abrasive envelope assembly in an attitude of use.

FIG. 2 is a perspective view illustrating the abrasive envelope with the flexible and resilient supporting block partially extracted to show the relationship between these two parts.

FIG. 3 is a vertical sectional view through the assembly.

FIG. 4 is a vertical sectional view through an assembly of a plurality of abrasive envelopes in an attitude in which they would be nested for shipment or sale.

FIG. 5 is a plan view of the envelope in its flat developed form illustrating the configuration of the blank from which the envelope is formed and the areas thereof on which adhesive is disposed.

FIG. 6 is a perspective view illustrating substantially full size another embodiment of the block and abrasive envelope assembly in an attitude of use.

FIG. 7 is a plan view in reduced scale of a strip of abrasive paper before it is folded along the dash line to form a pocket. A layer of an appropriate adhesive is shown by stippling along lateral edges of the strip.

FIG. 8 is a side elevational view of the pocket formed by folding the strip of FIG. 7 upon itself.

FIG. 9 is a vertical sectional view taken in the plane indicated by the line 9 -- 9 in FIG. 8.

FIG. 10 is a perspective view approximately one-half actual size illustrating the dual-wedged sanding block of the invention.

FIG. 11 is an edge view of the dual-wedged sanding block illustrated in FIG. 10.

DESCRIPTION OF PREFERRED EMBODIMENT

In terms of greater detail, as illustrated in FIGS. 1 and 2, the block and abrasive envelope assembly of one embodiment is designated generally by the numeral 2, the assembly preferably including flexible and resilient block 3 having a relatively thick edge portion 4, preferably rectangular as shown, from the long edges of which extend substantially flat surfaces 6, defined by parallel end edges 7 tapering to a relatively thin knife edge 8. The block is preferably fabricated from a flexible and resilient material such as one of the sponge-like synthetic resinous or natural materials like sponge rubber having sufficient density to provide strength and "body" to the block, while having sufficient resilience, flexibility and deformability to permit comfortable use as indicated in FIG. 1. It should be understood, however, that the block may be formed from a hard and inflexible material having the configuration illustrated and described, or it may use a combination of hard and soft materials to provide both rigidity and resilient deformability.

The abrasive envelope of the assembly illustrated in FIGS. 1 - 5 is conveniently fabricated from a flat blank designated generally by the numeral 12 in FIG. 5, the blank having opposite side edges 13 and 14 which cooperate with adjacent fold or score lines 16 and 17, respectively, to define triangular tabs 18 and 19 which, when folded along the score lines at right angles to the broad surfaces 21 and 22, as illustrated in FIG. 2, may be securely fastened to each other by an appropriate adhesive 23 so as to form an abrasive envelope or pocket, the interior surfaces of which have a configuration that is complimentary to the exterior surfaces of the support block 3.

The envelope blank is preferably provided with a transversely extending fold line 25, which may be in the nature of a score line, to guide folding of the blank so that the opposite end edges 24 and 26 of the blank lie opposite each other when the envelope is formed. The exterior surfaces of the portion 21 and 22 are coated with an abrasive material as indicated in FIGS. 1 and 2, which tightly adheres to the surface of the envelope and which may be used to abrade a surface requiring smoothing. Obviously, the entire sheet may be coated with an abrasive, either prior to blanking or subsequent thereto, so that even the tapered end edges are coated.

The envelope in its completed form is referred to generally by the numeral 27, and as indicated in FIG. 4, a multiplicity of the envelopes may be nested one within the other for packing, shipping and sale.

Referring to the embodiment illustrated in FIGS. 6 - 11, the envelope 27' is formed from a flat strip 28 of paper or cloth having abrasive material 29 on one surface thereof as shown. The opposite surface 31 of the strip may be provided with a transversely extending score line 32 midway between the ends of the strip and along which the strip may be folded to provide the folded or closed end 33 of the envelope or pocket.

Lateral edge portions of the strip are provided with a layer 34 of an appropriate adhesive so that when the strip is folded along the score line 32, the adhesive coated lateral edge portions on opposite sides of the score line will coincide in overlapping abutting relationship, thus cementing or otherwise securing the edge portions to form a pocket to receive the dual-wedged sanding block 36 of FIG. 10.

As there shown the dual-wedged sanding block 36 is formed preferably from a sponge-like material to provide flat tapering sides 37 and 38, tapering wedge-like from a relatively thick base end 39 to a sharp chisel-point 41. The lateral end edges 42 and 43 of the block are beveled to provide divergent surfaces 44 and 46 intercepting and angularly disposed, respectively, to wedge surfaces 37 and 38. Thus, a dual-wedged block is formed having a configuration and proportions such that when it is inserted into the envelope, the envelope is caused to generally conform to the configuration of the block as shown in FIG. 6.

Claims

I claim:

1. In combination:

a a unitary wedge shaped support block having relatively flat sides converging from a relatively thick edge to a relatively thin edge;

b a self-supporting envelope structure having an interior configured to receive the wedge shaped support block therewithin, said envelope being open at its end corresponding to the thick edge of said block and being closed at its end corresponding to the thin edge of said support block; and

c abrasive material disposed on selected exterior surfaces of said envelope structure.

2. The combination according to claim 1, in which said support block is fabricated from a flexible and resiliently compressible material.

3. The combination according to claim 1, in which said envelope structure is fabricated from paper stock and includes end edges formed by overlapped triangular tabs to provide a double thickness of said paper stock.

4. The combination according to claim 1, in which said wedge shaped support block is provided with end edges tapering from said flat converging sides to a relatively thin knife edge.

5. The combination according to claim 1, in which said wedge shaped support block is provided with lateral end edges beveled to provide divergent surfaces intercepting and angularly disposed to said relatively flat sides of the support block.

6. The combination according to claim 1, in which said envelope structure is formed from a single rectangular strip of material having an abrasive coating on one surface thereof, and a layer of adhesive along opposite longitudinal marginal edge portions of said strip whereby said adhesive coated portions overlap and abut in sealing relation when said strip is folded transversely midway between its ends to form a closed pocket to receive said support block.