US3790982A

US3790982A - Scraping blade

Info

Publication number: US3790982A
Application number: US00250189A
Authority: US
Inventors: J Whitsett
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-04
Filing date: 1972-05-04
Publication date: 1974-02-12
Anticipated expiration: 1991-02-12

Abstract

A scraping blade for use in a power operated rotary scraping device wherein the blade is formed of a generally flat sheet of material having a lower edge of finite thickness which provides the scraping edge. An aperture is formed through the blade with between 60 percent and about 80 percent of the length of the blade being disposed to one side of the center of the aperture.

Description

ited States Patent 1 hitsett Feb. 12, 1974 SCRAPING BLADE [76] Inventor: Jack W. Whitsett, 936 Castile Ave.,

Coral Gables, Fla. 33134 [22] Filed: May 4, 1972 [21] Appl. No.: 250,189

[56] References Cited 3,051,255 8/1962 Deely 175/265 FOREIGN PATENTS OR APPLICATIONS 479,798 2/1938 Great Britain 29/81 J 1,192,790

4/1959 France 15/93 R Primary ExaminerLeon G. Machlin Attorney, Agent, or FirmRoylance, Abrams, Berdo & Kaul [57] ABSTRACT A scraping blade for use in a power operated rotary scraping device wherein the blade is formed of a generally flat sheet of material having a lower edge of finite thickness which provides the scraping edge. An aperture is formed through the blade with between 60 UNITED STATES PATENTS percent and about 80 percent of the length of the blade being disposed to one side of the center of the 2,766,471 l0/l956 McKenzie 15/105 aperture 2,279,922 4/1942 Kramer 29/81 G 2,453,371 11/1948 Hobson 15/93 R 5 Claims, 3 Drawing Figures f\ )1 24 r|\\ I M S 22 38 l SCRAPING BLADE This invention relates to scraping blades and more particularly it relates to a scraping blade of the type which is particularly useful in a power operated rotary scraping device.

Scraping tools have been known and used in the art for some time. In general, such tools consist of a flat blade having a forward edge which provides the scraping edge and a fixed handle applied to the opposite end of the blade. In operation, the user grasps the handle and manually pushes the same to scrape the surface. However, it has been found that such tools are not at all satisfactory for a large scale scraping operation, such as removing the paint from a large wall, or removing a wall covering from one or several walls, or derusting or descaling of a large metallic surface.

Because of the unsatisfactory nature of such hand operated scraping tools, it, has been proposed in my copending application Ser. No. 60,434, filed Aug. 3, 1970, now US. Pat. No. 3,662,424, dated May 16, 1972, to provide a power operated rotary scraping device. In such aforementioned copending application,

there .is described a power operated scrapingdevice wherein a series of blades are attached to a rotary drive means, such as an electric drill to provide for a unique form of scraping apparatus which can accomplish jobs and tasks that'cannot be readily performed by manual scraping tools.

It is an object of the present invention to provide a I scraping blade which is particularly useful in a rotary scraping device of the power operated type, such as that disclosed in the aforesaid copending application.

Another object of the present invention is to provide a simple yet highly efficient scraping blade which can be operated by a power driven means to provide a positive scraping action to a surface which is to be scraped or cleaned.

Another object of the present invention is to provide a simple, durable and inexpensive scraping blade, which will nevertheless perform the functions which are desired of it when it is employed in a power operated rotary scraping device.

Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment thereof.

The foregoing objects are attained by providing a scraping blade in the form of a flat sheet of material having parallel side surfaces, opposedend edges, an upper edge and an opposed lower scraping edge. An aperture extends transversely through the blade to permit the same to be mounted and attached to a power operated rotary scraping device. The center axis for this aperture is longitudinally positioned along the blades so that between 60 percent and about 80- percent of the blade length is to one side of the center axis.

Referring now to the drawings, which form a part of this original disclosure: 7

FIG. 1 is a perspective view of a scraping blade in accordance with the principles of the present invention;

FIG. 2 is a side elevational view-f a modified form of scraping blade in accordance with the present invention; and

FIG. 3 is an end view of a scraping blade in accordance with the present invention, with an abrasive material adhered to the scraping edge thereof.

The scraping blade in accordance with the present invention is generally designated 10 and is formed of a flat sheet of material suitable for scraping purposes. Such material must necessarily be a generally rigid material and is preferably metal.

The scraping blade 10 has a pair of

parallel side surfaces

12 and 14 which are spaced apart by the thickness of the sheet of material, such thickness being designated t in FIG. 1. A pair of

opposed end edges

16 and 18 extend between the

side surfaces

12 and 14 at opposite ends of the blade 10. The blade also includes an upper edge 20 and alower edge 22, each of which extends transversely between the

side surfaces

12 and 14 and longitudinally between the

end edges

16 and 18. The lower edge 22 forms the scraping edge for the blade 10 and it can be seen that such edge has a finite thickness t and that it is not sharpened to a knife edge.

The length of the blade which .is defined by the longitudinal distance between the end edges l6 and 18 is designated L in FIG. 1 and such length can obviously be varied in accordance with the use to which the blade is to be put. A substantially circular aperture 24 extends transversely through the blade 10 along a center aperture axis 26 which is perpendicular to the

side sur faces

12 and 14. It can be seen that the distance longitudinally along the blade from the aperture center axis 26 to the end edge 18 is designated X in FIG. 1. This distance can be varied somewhat with its limits being defined by the

reference numerals

28 and 30 in FIG. 1. The reference numeral 28 represents one extreme position for the aperture center axis 26 and in such position about 60 percent of the length L is disposed to one side of the central axis. The reference-numeral 30 represents the other extreme position for the aperture center a 2 a in h a sit a bszvt .80. Esteem 9f t e length of the blade is disposed to one side of the aperture center axis.

It will thus be understood that the aperture center axis can be longitudinally adjusted to various different positions along the length of the blade 10, but the extremes of such position would be those shown at 28 and 30. It can thus be stated that the distance X between the center axis 26 of the aperture and the end edge 18 range between about 60 percent of the length L and about percent of the length The positioning of the aperture 24 along the blade length is considered quite important since this aperture defines the area where the blade is to be attached to its mounting means which, in turn, is attached to the power operated rotary scarping device. As shown in the aforementioned copending application, each scraping blade is mounted on a transversely extending member which projects through the apertureso that the blade is pivotal with respect to such transversely extending member. The weight of the blade to one side of the aperture exceeds that to the opposite side thereof, by virtueof the fact that more mass of the blade is on one side of the aperture than on the other side thereof, and this arrangement causes the blades to initially assume a tilted position when they are attached to the power operated rotary scraping device. However, when the power means is turned on and the blade is rotated, the rotational forces cause the blade to swing upwardly to assume a position generally parallel to the surface to be scraped. Usually, a pair of opposed blades are used and when such blades are mounted, they define between them a dihedral angle whose size can be conrolled somewhat by the positioning of the aperture 24 along the blade. Also, the positioning of the aperture 24 along the blade controls the effective scraping length of the blade.

For convenience, there has been shown in FIG. 1 the central axis or centerline 32 of the blade and the midpoint 34 thereof which intersects the central axis 32 midway between the

end edges

16 and 18. In FIG. 1, the aperture center axis 26 is shown intersecting perpendicularly with the

side surfaces

12 and 14 at the centerline 32. However, this arrangement is not the only one which can be used, and as shown in FIG. 2, the placement of the aperture can be varied between the upper and lower edges and 22, respectively. In FIG. 2, the reference numeral 36 designates an elevated position for the aperture 24 wherein such aperture is located between the blade central axis 32 and its upper edge 20. The reference numeral 38 represents the lower position of the aperture 24 wherein it is located between the blade central axis 32 and the lower or scraping edge 22 thereof. Again, this positioning of the blade aperture above or below the central axis 32 has an effect on the angular position which the blade assumes when it is coupled with the power operated rotary scraping device, as defined in my aforementioned copending application.

In FIG. 2, the lower or scraping edge 22 includes a first portion 22a which is parallel to the upper edge 20 and additionally includes a second portion 22b which extends upwardly between the end of the portion 22a and the end edge 18. This upwardly extending portion 22b can be a straight or angular section or it can be somewhat rounded. Blades made with a portion 22b as shown in FIG. 2 are particularly useful for removing paint from wood since they do not gouge the wood or make circular marks on the wood. Blades thatare angled in a straight or generally straight line along the portion 22b are effective for removing paint from grooves and are also quite beneficial for finishing boats.

In FIG. 3, it is illustrated that an abrasive material 40 can be adhered to the entire scraping edge 22 or at least a portion thereof. This abrasive material 40 can be silicon carbide or any other suitable material which would enhance the scraping ability of the scraping edge 22.

After reading the foregoing detailed description, it should be apparent that the objects set forth at the outset hereof have been successfully achieved by the present invention. Accordingly,

What is claimed is:

l. A scraping blade for use in a power operated r0- tary scraping device, comprising:

a substantially flat sheet of material having parallel side surfaces spaced apart by the thickness of said sheet;

said sheet having a pair of opposed end edges extending between said side surfaces;

said sheet also having upper and lower edges extending transversely between said side surfaces and extending longitudinally between said opposed end edges;

said blade having a substantial circular aperture extending transversely therethrough along a center axis which is perpendicular to said side surfaces;

said blade having a length defined by the longitudinal distance between said end edges;

said aperture being longitudinally positioned along said blade with the longitudinal distance from said aperture center axis to one of said end edges being between about 60 percent and about percent of said blade length,

wherein the planes containing said upper and lower edges are parallel and are perpendicular to the planes containing said side surfaces, and

wherein at least a substantial portion of said one end edge lies in a plane which is parallel to the plane containing the opposite end edge.

2. A scraping blade as defined in claim 1 wherein said blade has a central axis spaced equidistant from said upper and lower edges and wherein said aperture center axis intersects with said central axis.

3. A scraping blade as defined in claim 1 wherein said blade has a central axis spaced equidistant from said upper and lower edges and wherein said aperture center axis is disposed between said central axis and one of said upper and lower edges.

4. A scraping blade as defined in claim 2 wherein said lower edge constitutes the scraping edge and wherein a first portion thereof is parallel to said upper edge while a second portion thereof extends upwardly between the end of said first portion and said one end edge.

5. A scraping blade as defined in claim 4 wherein said lower edge constitutes the scraping edge and wherein a coating of abrasive material is adhered to at least a portion of said scraping edge.

Claims

1. A scraping blade for use in a power operated rotary scraping device, comprising: a substantially flat sheet of material having parallel side surfaces spaced apart by the thickness of said sheet; said sheet having a pair of opposed end edges extending between said side surfaces; said sheet also having upper and lower edges extending transversely between said side surfaces and extending longitudinally between said opposed end edges; said blade having a substantial circular aperture extending transversely therethrough along a center axis which is perpendicular to said side surfaces; said blade having a length defined by the longitudinal distance between said end edges; said aperture being longitudinally positioned along said blade with the longitudinal distance from said aperture center axis to one of said end edges being between about 60 percent and about 80 percent of said blade length, wherein the planes containing said upper and lower edges are parallel and are perpendicular to the planes containing said side surfaces, and wherein at least a substantial portion of said one end edge lies in a plane which is parallel to the plane containing the opposite end edge.