US3129540A

US3129540A - Flexible sanding block

Info

Publication number: US3129540A
Application number: US155012A
Authority: US
Inventors: Fred G Valles
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-11-27
Filing date: 1961-11-27
Publication date: 1964-04-21
Anticipated expiration: 1981-04-21

Description

April 21, 1964 F. e. VALLES FLEXIBLE SANDING BLOCK Filed Nov. 27, 1961 .Ffza. 2.

INVENTOR. Pies-0 GI VALLE'S BY OBQ/AA/ & BLACKHAM A 7'TO/QA/5 rs United htates Fatent 3,129,540 FLEXELE SANDENG BLOCK Fred G. Valles, 14372 Purdy St, Westminster, Calif. Filed Nov. 27, 1961, Ser. No. 155,012 1 Claim. ((11. 51-487) This invention pertains to a new and improved flexible standing block and, more specifically, to sanding blocks which are used with sheets of common sand paper.

The term sand paper as commonly used at the present time designates a sheet of paper or cloth which has been coated on one of its surfaces with an adherent layer of an abrasive material. Not infrequently such an abrasive material is sufliciently fine so that it is capable of exercising a mild polislnng action. Because of the construction of common sheets of sand paper as the term is broadly employed it has long been recognized that it is advisable to use such paper in conjunction with a holding structure in order to facilitate sanding operations. Innumerable different types of sanding blocks or equivalent structures designed to hold sand paper during a sanding operation have been designed and constructed in the past. The vast majority of such structures are of a rigid character. Thus, for example, on many occasions sand paper has been wrapped around a portion of a solid wood block in order to be used in sanding.

On many occasions it is desired to sand curved surfaces, as, for example, the surface of an automotive fender or the like having a compound curvature. Obviously rigid sanding blocks are not completely satisfactory for use in such operations because of the fact that with them only point or line contact can be obtained against many different types of curved surfaces.

Rigid sanding blocks are also disadvantageous for other reasons. Such blocks tend to cause undue muscle tiredness after they have been used for prolonged periods by virtue of the fact that they do not exercise a cushioning effect with respect to the muscles of the hand. Further, rigid blocks in many cases are apt to cause a certain amount of scratching of a surface since they are incapable of giving to a significant extent in such a manner as to accommodate edges of sand paper or the like so that such edges do not cause undesired scarring of the surface.

A broad object of the present invention is to provide new and improved flexible sanding blocks which overcome limitations and disadvantages of prior sanding blocks such as briefly indicated in the preceding discussion. A related object of the present invention is to provide new and improved sanding blocks which may be easily utilized and which are capable of being bent so as to conform to the configuration of various articles of a compound or other curvature in order to facilitate the sanding of such curved shapes. A further object of the present invention is to provide flexible sanding blocks as, herein described which may be used so as to obtain effective sanding from virtually all portions of a sheet of sand paper. Another object of the present invention is to provide flexible sanding blocks which are capable of being easily and conveniently manufactured at a comparatively nominal cost and which are capable of being used satisfactorily over extremely prolonged periods.

These and various other objects of this invention, as well as many specific advantages of it, will be more fully apparent from a detailed consideration of the remainder of this specification including the appended claims and the accompanying drawing in which:

FIG. 1 is a perspective view of a flexible sanding block of the present invention;

FIG. 2 is a cross-sectional view taken at line 2--2 of FIG. 1.

The accompanying drawing is primarily intended so as to illustrate the nature or character of a presently preferred embodiment or form of a sanding block of this invention. From a consideration of the drawing and of the remainder of this specification it will be realized that various changes of a routine design or engineering nature may be made in the precise sanding block illustrated in the drawing without departing from the inventive features or principles embodied within this sanding block. For this reason the accompanying drawing is not to be considered as limiting this invention.

As an aid to understanding this invention it can be stated in essentially summary form that it concerns a flexible sanding block, each of which includes: a base having front and back surfaces, side edges and end edges; a holding strap attached to one of these end edges so as to extend from it. Preferably both the base and the holding strap are formed of a flexible resilient material. This construction is designed so that a piece of sand paper or the equivalent can be wrapped around the base and so that the holding strap may be located against either the front or back surfaces of the base in contact with the sand paper wrapped around it.

The actual details of this invention are best more fully explained by referring to the accompanying drawing in which there is shown a flexible sanding block 10 of the presentinvention which includes a base 12 having front and back sides 14 and 16, respectively, side edges 18 and end edges 20. At one of these end edges 20 there is attached to the base 12 an elongated holding strap 22 having front and back surfaces 24 and 26, respectively, side edges 28 and end edges 3%. It will be noted that one of these end edges 30 is contiguous with one of the end edges 29, and that the width of the holding strap 22 in the block 10 is the same as the width of the base 12. It will be also noted that the holding strap 22 is nearly as long as the base 12. The strap 22 is preferably no longer than the base 12. Also it will be obvious from the foregoing that both the base 12 and the holding strap 22 are of a rectilinear shape or configuration.

Preferably both the base 12 and the holding strap 22 are formed out of flexible, resilient material. Presently preferred results have been achieved by forming the base 12 and the holding strap 22 out of an elongated strip of so-called foam rubber containing a number of air pockets. Flexible equivalent strips can be used, however, with the present invention. When the base .12 and the holding strap 22 are formed out of foam rubber it is normally preferred to cover the exposed

surfaces

12, 14, 24 and 26 by thin layers 32 of a relatively heavy cloth. These layers 32 may be secured in place through the use of an adhesive or in other equivalent manners. These layers 32 are used since foam rubber is easily damaged. These layers 32 adequately protect the foam rubber against damage occurring by reason of abrasion between it and other materials or surfaces.

In order to complete the sanding block 10 is is normally preferred to locate around the holding strap '22 intermediate its ends an elastic band 34. This band 34 preferably is of sufficiently small dimension so that it fits loosely upon the strap 22 without falling off of the strap. When the band 34- is formed in this manner there is no necessity for securing it to the strap 22 by an adhesive or the like.

When the block '10 is formed so that the base 12 and the holding strap 22 are formed out of a single strip of foam rubber as indicated in the preceding, it is normally preferred to create the base 12 by folding an end portion of the strip over against the center portion of it, and by securing this end portion to the center portion of it through the use of a conventional adhesive or other equivalent means. When the base 12 is formed in this manner out of a single strip of material, the remaining 3 end portion of the strip used in creating these two parts serves as a holding strap 22.

During the use of the flexible sanding block a sheet 36 of common sand paper or the like is folded around the base 12 so as to extend-across the front and back surfaces 14 and 16 and around the side edges 18. The holding strap 22 is then folded back along either the surface 14 or the surface 16 and, if desired, the hand of an individual using the block 10 is inserted in between the strap 22 and the band 34 so as to distend this band. At this point a block 10 may be used. During such use the friction between the holding strap 22 and the covered surface of the sheet 36 will be sufficient to prevent any relative motion between the base 12 and the holding strap 22. As a consequence of this as a hand engaging the holding strap 22 is moved back and forth the entire sanding block 10 Will be moved in a corresponding manner. Further, as the block '10 is used, the hand of the individual using it may be readily bent or deformed slightly so as to cause the entire block 10 and the sheet 36 held by it to deform so as to adequately sand comparatively large areas of curved surfaces such as automotive surfaces having a compound curvature.

After the block 10 has been used so that the portion of the sheet 36 remote from the holding strap 22 has been worn to a sufficient extent so that no further material amount of sanding can be achieved from it, the holding strap 22 may merely be turned with respect to the base 12 so as to lie along thersurface 14 or 16 against which it was not previously located. The entire sanding block 10 may be then used in the same manner as described in the preceding. When all portions of the sheet 36 become worn it is a comparatively simple matter to move the holding strap 22 slightly so as to enable another sheet of sand paper (not shown) to be slipped around the base 12.

If desired, the thickness of the base 12 and the holding strap 22 in the block 10 may be varied within comparatively wide limits. This is because the holding strap 22 merely serves a holding and pressure distributing function during the use of the block 10*. The thickness of either the holding strap 22 or the base 12 should be varied depending upon the cushioning elfect desired during the use of the block 10 so as to prevent undue fatigue. Presently preferred results are considered to be achieved when the holding strap 22 is approximately one-half as thick as the base 12 and when the strap 22 is about onefourth inch thick and when the base 12 is about one-half inch thick. This thickness allows the hand of a user of a block of this invention to be spared so that there is no reasonable danger of abrasion against the hand.

Because of the nature of this invention it is to be considered as being limited solely by the appended claim forming a part of this dsclosure.

I claim:

A flexible sanding block which includes:

a base of rectilinear shape formed of a flexible resilient material, said base having front and back surfaces, side edges and end edges;

a holding strap of general rectilinear configuration formed of a flexible resilient material, said holding strap having front and back surfaces, side edges and end edges,

said base and said holding strap being formed of the same piece of flexible resilient material so that one of the end edges of said strap is continuous with one of the end edges of said base, said holding strap being as wide as said base and being no longer than said base, said holding strap being folded over said base so that said back surface of said holding strap faces and is substantially parallel to said back surface of said base;

additional flexible resilient material secured to said base so that said base is substantially thicker than said strap;

a fabric layer secured to said front surface of said base and to said front surface of said holding strap and extending around the fold therebetween; and

an elastic band fitted around said holding strap and resiliently engaging said holding strap, said elastic band being deformable, said elastic band providing easy manual retention of said flexible sanding block.

References Cited in the file of this patent UNITED STATES PATENTS 577,860 Keighley Mar. 2, 1897 2,040,599 Davies May 12, 1936 2,221,173 Gutsell Nov. 12, 1940 2,256,098 Mauldin Sept. 16, 1941 2,804,729 Dahlstrom Sept. 3, 1957