US3110917A

US3110917A - Chalk board eraser

Info

Publication number: US3110917A
Application number: US203022A
Authority: US
Inventors: Jr Lewis D Mcpeek
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-06-18
Filing date: 1962-06-18
Publication date: 1963-11-19
Anticipated expiration: 1980-11-19

Description

Nov. 19, 1963 D. MCPEEK, JR 3,110,917

CHALK BOARD ERASER Filed June 18, 1962 INVENTOR.

BYMAHONEYJMLLER a RAMBO LEWIS D. McPEEK,JR v

, 3,11%,917 Patented Nov. 19, l 963 3,11%,917 CHALK BGARD ERASER Lewis D. Mclleek, Jr, 2505 Wicltlifle Road, Columbus, Uhio Filed June 18, 1962, Ser. No. 203,022 7 Claims. (El. -118) This invention relates generally to a chalk board eraser. It relates, more specifically, to a chalk board eraser'having a container for chalk storage and a magnetic holding member for cooperatively engaging a supporting bracket attached to a wall member.

The usual type of chalk board eraser that has hereofore been utilized by large numbers of educational institutions as well as various private organizations and individuals is designed solely for erasing purposes. The sticks of chalk provided for use are generally stored for convenience in a chalk tray attached to the lower marginal edge of a chalk board. Erasers are also generally placed on the chalk tray when not in use. With this type of equipment, chalk is often inadvertently knocked out of the chalk tray and broken into small pieces which are unusable and must be discarded Also, chalk is frequently misplaced or otherwise lost which further increases the cost of maintaining adequate supplies of chalk and inconveniences the user. An eraser, after use, contains a quantity of chalk dust which is at least partially deposited in the chalk tray each time the eraser is replaced. The sticks of chalk also add to the accumulation of chalk dust in the tray. In most educational institutions, the responsibility for cleaning the chalk trays is given to the building custodians who must also perform numerous other maintenance duties. Thus, maintenance costs are not only increased but the building custodians must devote a portion of their time to this cleaning task which may be more advantageously utilized for other duties. Erasers of the type heretofore utilized are often constructed with a plurality of compressible felt strips secured in an edge contacting relationship to a relatively stiff backing member. The felt strips are generally secured to the backing member by stitching with a heavy thread. A portion of the thread is exposed at a surface of the backing member and is therefore subjected to constant wear resulting in breakage. Such an eraser is also flexible which materially affects the efliciency of the eraser and the thread breakage increases the flexibility further reducing the efficiency. Consequently, an eraser of this type becomes unserviceable and must be discarded before the felt strips are so worn as to be ineffective.

It is, therefore, the primary object of this invention to provide a chalk board eraser having a container to carry a supply of chalk for the convenience of the user and which eliminates the necessity of providing a chalk tray attached to a chalk board.

it is another object of this invention to provide a chalk board eraser having an eraser portion with a chalk container secured thereto and including a cover cooperatively engaging the eraser portion which is movable between a closed and an open position relative to the container.

It is a further object of this invention to provide a chalk board eraser having a rigidly constructed chalk container secured to an eraser portion for increasing the structural strength of the eraser portion and including a cover and handle of U-shape which slidably engages the eraser portion and is movable between a closed and an open position relative to the container.

It is a still further object of this invention to provide a chalk board eraser having a chalk container with 'a cover and handle movable between a closed and an open position relative to the container and a magnetic member United States Patent Ofiice carried by the container for releasably attaching the eraser to a cooperative supporting bracket.

It is also an object of this invention to provide a chalk board eraser having a rigid-1y constructed chalk container that may be economically fabricated from a thermosetting resinous material secured to an eraser portion which substantially increases the life and efficiency of the eraser portion.

These and other objects and advantages of this invention will be readily apparent from the following detailed description of an embodiment thereof and the accompanying drawings, in which:

FIGURE 1 is a perspective view of a bracket member supporting a chalk board eraser having a chalk container and a cover and handle;

FIGURE 2 is an enlarged perspective view of the chalk board eraser with the cover in a partially open position;

FIGURE 3 is a vertical transverse sectional view taken along line 3-3 of FIGURE 4;

FIGURE 4 is a vertical longitudinal sectional View taken along line 4-4 of FIGURE 3; and

FIGURE 5 is fragmentary horizontal sectional view taken along line 5-5 of FIGURE 2.

Referring to the drawing, a chalk board eraser constructed in accordance with this invention is illustrated in detail. The eraser includes an eraser body It? carried on the lower surface of a relatively rigid backing member 11. These two components may be of the usual type of construction employed in the manufacture of commercial-ly available chalk board erasers designed only for erasing purposes. In this type of eraser, the body '10 is fabricated from a plurality of strips 12 of compressible felt material arranged to form a laminated structure with the opposed surfaces of adjacent strips in contacting engagement. The backing member l-l is a flat panel of rectangular form fabricated as a laminated structure of fibrous sheets. To assemble the eraser body 10' and the backing member 11, the felt strips 12 are positioned in an edge contacting relationship with the lower surface of the backing member and secured thereto by sewing with a fiber thread 13 (see FIGURE 3). Preferably, each thread is lock stitched and extends longitudinally of the felt strips 12 which it secures. The backing member 11 is of a width greater than the combined thickness of the felt strips and the longitudinally extending marginal edges 11a and 11b extend a distance outwardly from the surface of each adjacent strip 12 forming a shoulder at each side of the eraser body lid.

Secured to the upper surface of the backing member is a container 14 for the storage of several sticks of chalk. The sticks of chalk are denoted by the letter A in the several figures. The container 14 is an elongated plate of rectangular cross-section having a width substantially equal to that of the backing member 1.1. Each longitudinal edge surface 14a and 14b thereof is aligned with the surface of the adjacent marginal edge 11a and 11b, respectively, of the backing member. The container 14 may 'be secured to the backing member 11 by a relatively thin layer of adhesive material 15 disposed between the adjacent surfaces thereof or in any other suitable manner. Formed in the container are a plurality of longitudinally extending, spaced parallel channels 16 which open at the upper surface. Each channel 16 is rectangular in crosssection with closed ends 17 spaced a distance inwardly of the adjacent container ends to fully receive a stick of chalk A. Preferably the thickness of the container 14 is substantially greater'than the diameter of the chalk A in order that the channels 16 will not extend completely through the container and decrease the rigidity thereof. To facilitate removal of a stick of chalk A from its channel, the channel end-s 17 are arcuately curved and sloped upwardly as shown in FIGURES 2 and 4. in the present embodiment, the container 14 is of a molded or cast construction utilizing a suitable thermos-etting resinous material which forms a rigid structure. Other material, such as wood, may be utilized; however, their cost of manufacture will be substantially greater.

A cover and handle is provided for the container 14 to retain the stick of chalk A in their respective channcls 16 while the eraser is being used. The cover 18 consists of an elongated U-form channel having spaced parallcl flanges l9 and 2t interconnected by a flat web 21. To close the container 14, the cover 18 is placed with the web 21 in overlying relationship to the upper surface thereof and the flanges 19 and 2b disposed parallel to the edges 14a and 14b, respectively, of the container. Each flange 19 and 2b is of suflicient width to extend slightly below the lower surface of the backing member 111 terminating in a marginal edge 1% and Zita, respectively. The edges 19a and 29a are turned inwardly, FIGURES 2 and 3, to slidably engage the shoulder formed by the backing member 11 and the eraser body It). Thus, the cover 18 may be readily moved relative to the container 14 between a closed position covering the channels 16 and a partially open position, as in FTGURE 2, where the chalk may be removed. When the cover 18 is in the closed position, it also serves as a handle which may be conveniently grasped thereby facilitating an erasing operation. By properly dimensioning the flanges it and 29, their respective edges 19a and 2011 will frictionally engage the backing member 11 to maintain the cover ill in the desired position. The cover is is preferably fabricated from steel [for rigidity although other suitable materials, thermosetting resinous materials for example, may be utilized.

To further assure that the cover will remain in the desired position, particularly when the eraser is vertically supported as in FIGURE 1, an inwardly protruding indentation 22 of a generally spherical shape is formed in at least one of the flanges it? or 2% opposite the adjacent edge 14a or 1417, respectively, of the container 14. In the present embodiment, two such indentations 22 are formed in the flange 20 with each indentation spaced a distance inwardly of the opposite ends. Each indentation 22 (see FIGURE extends a distance laterally from the inwardly facing surface of the flange to engage the edge 14]) thereby increasing thefrictional resistance to movement of the cover. A cover 18 fabricated from steel is sufficiently resilient to provide the necessary inwardly directed force to produce the desired friction. The utilization of indentations or other friction producing devices is of particular importance where close manufacturing toleranccs are not observed and the inturned edges 19a and 29:1 do not provide sufiicient frictional resistance.

In accordance with this invention, the eraser is also provided with a magnetic member 23 [for cooperatively engaging a supporting bracket 24. The magnetic member 23; consists of an elongated, permanently magnetized steel bar carried by the eraser. The magnet bar 23 may be disposed in a recess formed in an end of the container or, preferably, integrally molded therewith where the cont ainer is fabricated from a thermosetting resinous material. One surface of the magnet 23 which is exposed forms a coplanar surface with the adjacent end surface of the container.

The bracket 24 comprises and L-shaped fiat, magnetic metal strip which is secured to a vertically disposed wall member 25 by several screws 26 or other suitable fastening means. One leg or" the bracket 24 extends a distance horizontally outward from the wall 25 to provide an armature for the magnet 23. An eraser is supported from the bracket 24 by placing the eraser body Ill adjacent the vertically disposed leg of the bracket and the end of the container with the magnet 23 adjacent the horizontal leg. The magnet 23 will be attracted to the bracket and releasably suspend the eraser therefrom. The magnet must be sufiiciently strong to overcome the weight of the eraser.

It is readily apparent that the chalk board eraser of this invention provides a safe and conveni nt storage space for chalk to prevent loss or breakage. The container not only stores the, necessary sticks of chalk where they are readily accessible to the user but strengthens the backing member thereby increasing the efficiency of the eraser body and prolonging its life. The slidably mounted cover permits the chalk to be readily removed from the container and forms a handle that is more conveniently gripped. The supporting bracket and cooperative magnetic holding members provides a convenient support for the eraser which, in conjunction with the chalk container, eliminates the necessity of providing a relatively expensive chalk tray.

According to the provisions of the patent statutes, the principles of this invention have been explained and have been illustrated and described in what is now considered to represent the best embodiment. However, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specificallv illustrated and described.

Having thus described this invention, what is claimed 1s:

1. A chalk board eraser comprising a compressible eraser body, an elongated, flat relatively rigid backing member which carries said body at its lower surface, said backing member having a pair of opposed, longitudinally extending edge portions, a chalk container attached to the upper surface of said backing member having a plurality of elongated chalk receiving channels formed therein and opening upwardly, and a cover for said container, said cover including a pair of longitudinally extending marginal edge portions which extend below said backing member and cooperatively engage the edge portions thereof in slidably mounting the cover on said container and said backing member for longitudinal sliding movement relative to said container.

2. A chalk board eraser comprising a compressible eraser body, an elongated, flat relatively rigid backing member fabricated from a fibrous material which carries said body at its lower surface, said backing member having a pair of opposed, longitudinally extending edge portions which provide a shoulder at each side adjacent said body, a container attached to the upper surface of said backing member having a pair of opposed, longitudinally extending edge surfaces, a slidable cover for said container, said cover being of inverted U-shape to serve also as a handle and having a marginal edge disposed adjacent each edge surface of said container and which extends beneath and cooperates with and frictionally engages said shoulders in slidably mounting the cover on said backing member for sliding movement longitudinally thereof be tween covering position and at least partially uncovering position relative to said container, said container and said cover having cooperating friction producing means substantially preventing free sliding movement of said cover relative to said container.

3. A chalk board eraser according to claim 2 wherein said friction producing means includes at least one protuberance carried by said cover maintained in contacting engagement with a surface of said container.

4. A chalk board eraser according to claim 3 wherein said protuberance comprises an indentation of spherical shape integrally formed with the marginal edge of said cover and extending a distance laterally therefrom to engage the adjacent edge surface of said container.

5. A chalk board eraser comprising a compressible eraser body, an elongated flat relatively rigid backing member which carries said body at its lower surface, said backing member having a pair of opposed, longitudinally extending edge portions, a container attached to the upper surface of said backing member adapted to receive a plurality of chalk sticks, and a cover for said container, said cover including a pair of longitudinally extending marginal edge portions which extend below said backing member and cooperatively engage the edge portions; thereof in slidably mounting the cover on said container and said backing member for longitudinal sliding movement relative to said container.

6. A chalk board eraser according to claim 5 which includes a magnetic holding member carried by said container for cooperatively engaging a bracket and detachably suspending the eraser therefrom.

7. A chalk board eraser according to claim 6 wherein said container is elongated and said magnetic member is fixed in a recess formed in an end of said container with an exposed surface of said magnetic member forming a 6 coplanar surface with the adjacent surface of said container end.

References Cited in the file of this patent UNITED STATES PATENTS 160,104 Joseph et a1 Feb. 23, 1875 582,612 Barrie May 18, 1897 1,061,276 Ellis May 13, 1913 2,506,600 Kassovic May 9, 1950 2,642,999 McPherson June 23, 1953 2,842,791 Statler July 15, 1958 3,031,711 Herman et a1 -4-.. May 1, 1962

Claims

5. A CHALK BOARD ERASER COMPRISING A COMPRESSIBLE ERASER BODY, AN ELONGATED FLAT RELATIVELY RIGID BACKING MEMBER WHICH CARRIES SAID BODY AT ITS LOWER SURFACE, SAID BACKING MEMBER HAVING A PAIR OF OPPOSED, LONGITUDINALLY EXTENDING EDGE PORTIONS, A CONTAINER ATTACHED TO THE UPPER SURFACE OF SAID BACKING MEMBER ADAPTED TO RECEIVE A PLURALITY OF CHALK STICKS, AND A COVER FOR SAID CONTAINER, SAID COVER INCLUDING A PAIR OF LONGITUDINALLY EXTENDING MARGINAL EDGE PORTIONS WHICH EXTEND BELOW SAID BACKING MEMBER AND COOPERATIVELY ENGAGE THE EDGE PORTIONS THEREOF IN SLIDABLY MOUNTING THE COVER ON SAID CONTAINER AND SAID BACKING MEMBER FOR LONGITUDINAL SLIDING MOVEMENT RELATIVE TO SAID CONTAINER.