US2823404A - Two-piece toothbrush - Google Patents

Description

Feb. 18, 1958 R, M, HYMAN 2,823,404

TWO-PIECE TOOTHBRUSH Filed March 1, 1955 .57 Z7517 ZUT" Box/4.60 M /7J MA/v United States Patent TWO-PIECE TOOTHBRUSH Richard M. Hyman, Toledo, Ohio, assignor to Owens Brush Company, Toledo, Ohio, a corporation of Ohio Application March 1, 1955, Serial No. 491,254

2 Claims. (Cl. 15-145) This invention relates to collapsible handles for brushes and the like instruments, and more particularly, to a collapsible toothbrush having a two-piece handle.

A number of prior art workers have suggested collapsible toothbrush structures; but in most instances these leave something to be desired in that they are too awkward to handle, either too complicated or not sturdy enough, too diflicult to manufacture, difficult to keep clean, etc. In contrast, the unitary or integral toothbrush handle now employed almost universally made from cellulose acetate or cellulose acetate butyrate has a number of advantages as 'a toothbrush handle, but such toothbrush handle is not collapsible and, particularly for traveling kits and similar uses where space is of importance, the demand for collapsible toothbrushes has not been satisfied.

The instant invention provides a unique collapsible toothbrush structure which is readily made and readily assembled and disassembled. Moreover, this toothbrush structure may be made of the cellulose acetate and cellulose acetate butyrate materials hereinbefore mentioned as the most acceptable commercially for this purpose. In addition, the instant toothbrush structure provides a handle portion, at the junction between the two pieces of the handle, which has a number of advantages in manual graspability, as well as in assembly and disassembly.

It is, therefore, an important object of the instant invention to provide an improved collapsible toothbrush or similar tool.

I It is another important object of the instant invention to provide a collapsible toothbrush formed of a first member having a generally elongated flat body with a generally longitudinally extending slot formed in one end thereof, a second member having a generally fiat body with generally longitudinally extending grooves formed on opposite sides of one end thereof and separated by a thin wall fitting into the slot in a snug fit to removably receive the two members together, and brush bristles mounted on the end of one of said members opposite the end thereof secured to the other.

4 Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed disclosure thereof and drawings attached hereto and made a part hereof.

0n the drawings:

Figure 1 is aside elevational view, with part broken away and part shown in section, of a collapsible toothbrush embodying the instant invention;

Figure 2 is an exploded top plan of the toothbrush assembly of Figure 1, showing part in section; and

''Figure 3 is an enlarged detail sectional view of the joined portions of the two members shown in Figure 1 taken substantially along the line IIIIII of Figure 1.

As shown on the drawings:

' A toothbrush, indicated generally by the reference numeral 10, embodying the instant invention comprises a first member 11 having a generally elongated fiat body having a generally longitudinally extending slot 12 formed in one end 11a thereof, a second member 13 having a 2,823,404 Patented Feb. 18, 1958 7 end 13b of the second member 13 opposite the end 13a thereof secured to the other member 11.

It will be appreciated that the brush bristles 16 might be mounted at the far end 11b of the first member with only minor changes in the structure. As here shown, the far end of the first member 11b is provided with an aperture 17 so that the brush may be hung on a peg in the customary manner. It will also be appreciated, that the instant brush handle structure is not limited solely to a toothbrush, but may be used on a number of other types of brushes or on tools of comparable character and strength requirements.

As here shown, particularly in Figure 2, the second member 13, which carries the bristles 16 at its outer end 13b possesses the general shape characteristics of a fiat elongated body at the securing end 13a, but is narrowed somewhat to a substantially circular neck portion 13c before flattening out again to provide the bristle mounting head portion 13b. This rounded neck portion intermediate the securing portion 13a and the bristle bearing portion 13b does facilitate the handling of the brush and also adds to the general ornamental character thereof; but the important feature of manual graspability afforded by the instant brush structure 10 is in the secured or interlocking end portions 11a and 13a of the two members 11 and 13, respectively. It will be seen that by the use of elongated flattened body members in the regions where the two members 11 and 13 are secured together a cross section (shown in detail in Figure 3) is provided with the shape of a plus sign. In eifect, this portion is provided with a central interlocking portion formed by the interengagement of the groove 12 and the thin wall 15 with radially outwardly extending ribs A and B derived from the second member 13 and extending laterally with respect to the brush head 13b, and C and D provided by the first member 11 and extending in the vertical plane with respect to the brush head 13b. These ridges A, B, C and D provide unusually handy gripping elements which permit rotation of the brush 10 between the thumb and index finger during use thereof and alforded a firm grip as well as guide members in the form of the ridges A, B, C and D to indicate the angle at which the brush head 13b and bristle 16 are tilted. In addition, the ridges A, B, C and D afford readily graspable means for disassembling the brush 10. For example, the first member 11 may be grasped in the palm of the hand and the second member 13 may he slipped off the first member 11 merely by pressure of the thumb against the ridges A or B. 7

Referring now to Figure 3, it will be noted that there are certain specific structural features in the two members 11 and 13 which afford unique interlocking between the two members 11 and 13 by virtue of complementary grooves and ridges opposing each other so that the grooves on one of the members 11 or 13 will receive the ridges on the other of such members during interlocking engagement. The interlocking groove and ridge arrangement which will be described in detail is of critical importance in the instant invention because it provides secure interlocking by snug or forced fit between the elements 11 and 13 in such a manner that the usual toothbrush forming material such as cellulose acetate and cellulose acetate butyrate may be employed and will hold up under numerous assemblies and disassemblies. A single slot and a single thin wall received in the slot may have a tendency to develop permanent distortion in response to the force fit applied therebetween so as to fit only loosely after a number of assemblies and disassemblies. On the other hand, an arrangement wherein a force fit is provided between opposed ridges and grooves as well as the main securing fit between the thin wall and the slot provides a number of'contiguous face portions whereat force fit conditions exist so that distortion or weakness created in the fit along one pair of contiguous faces will be compensated for by increased friction between another set of contiguous faces.

Referring in detail to Figure 3, it will be noted that the first member 11 has a generally elliptical cross-section, with the major axis extending generally in a horizontal direction and the minor axis extending generally in a vertical direction and the slot 12 therein being aligned generally with the minor axis. The member 11 is bifurcated at the end 11a (Figures 1 and 2) to provide a first' pair of legs, he'reinbefore referred to as the ridges C and D which extend along opposite ends of the ellipse major axis. A first pair of opposed grooves 18a and 18b are formed along the inside of the first pair of legs C and D thereby defining a first pair of opposed ridges 19a and 1% extending along the inside of the first pair of legs C and D. It will be noted that the groove 18a is cut in from the bottom side (as shown in Figure 3) of the member 11 and is broader than the slot 12 which is defined between the first pair of opposed ridges 19a and 19b; and the other groove 18b is cut in from the top side of the first member 11 so as to define the side walls of the ridges 19a and 1912 on the top side.

The second member 13 is also generally elliptical in cross-section, with the ellipse major axis extending generally vertically (in Figure 3) and the minor axis extending generally horizontally. The general elliptical cross-section of the second member 13 is substantially the same size as that or": the first member 11 and this results in the generally plus sign shaped cross-section of the two members in interlocking engagement, thereby providing advantageous gripping means in the form of the ridges or legs A, B, C and D. In the second member 13, it will be noted that it is bifurcated at the end 13a here shown in Figure 3 to provide a second pair of legs A and B extending along opposite ends of the ellipse major axis. A second pair of opposed grooves Zfia and 2% are formed along the inside of the second pair of legs A and B thereby defining a second pair of opposed ridges 21a and 2112 which are received snugly by the first pair of opposed grooves 18a and 18b in the first member 11. Actually, it will be noted that the second pair of opposed grooves 20a and 29b formed in the second member 13 receive and snugly fit inside portions C and D of the legs C and D. In the next set of grooves 18a and 18b and ridges 21a and 21b which interlock, the groove portions 18a and 1812 are formed in the first member 11 and the ridges 21a and 21/) are provided by the second member 13.

Finally, in the middle of the assembly, the thin wall 15 is received and snugly fit in the slot 12. However, the thin wall 15 extends between the second pair of ridges 21a and 21b and defines therewith a third pair of opposed grooves, previously indicated as the only grooves 14a and 14b or the sole pair of grooves in the generic concept, and indicated in Figure 3 as 14a and 14b. This third pair of opposed grooves 14a and 14b receives the first pair of opposed ridges 19a and 19b on the member 11 and snugly fits these ridges not only with respect to the thin central wall 15 and slot 12, but also with respect to the side walls of the grooves 14a and 14b and the ridges 19a and 19b.

In the formation of the instant members 11 and 13, particularly at the bifurcated ends 11a and 13a thereof, the elliptical or generally elliptical cross-section should involve a major axis of about one-half inch or about two to four times the minor axis in each case. Actually, the cross-sectional shape is that of a flattened ellipse in the preferred embodiment. The slot 12 and thin wall portion 15 should preferably be from about one to about three times the major axis or the maximum lateral dimension of each of the members 11 and 13; and the members 11 and 13 are generally elongated flattened bodies having lengths of from about five to about ten times the major axis or maximum lateral dimension. The two members 11 and 1-3 are assembled and disassembled by longitudinal movement with respect to either of them and the slot 12 and thin wall15 therein are both longitudinally aligned with respect to the. members 11 or 13 carrying the same. So also are the various grooves hereinbefore described.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a collapsible toothbrush, in combination, a first generally elongated member having a. generally elliptical cross-section bifurcated at one end to provide a first pair of legs extending along opposite ends of the ellipse major axis, a first pair of opposed grooves formed along the inside of said first pair of legs thereby defining a first pair of opposed ridges extending along theinside of said first pair of legs, said ridges defining therebetween a narrow slot generally aligned with the ellipse. minor axis, a second generally elongated member having substantially the same sized generally elliptical in crosssection bifurcated at one end to provide a second pairof legs extending along opposite ends of the ellipse major axis, a second pair of opposed grooves formed along the inside of said second pair of legs thereby defining a second pair of opposed ridges received by said first pair of opposed grooves, a thin wall extending between said second pair of ridges and defining with said second pair of ridges a third pair of opposed grooves receiving said first pair of opposed ridges, said thin wall snugly fitting said slot to removably secure the two members together, and brush bristles mounted on the end of one of said members opposite the end thereof secured to the other, the secured ends of said members having a generally plus sign shaped cross section for improved manual graspability in manipulation of the brush.

2. In a collapsible toothbrush, in combination, a first generally elongated member having a generally elliptical cross-section with a thin slot formed at one end thereof generally along the minor axis of the elliptical crosssection and grooves formed in alignment with said, slot and on opposite sides thereof, a second generally elongated member having a generally elliptical cross-section with generally longitudinally extending grooves formed on opposite sides of one end thereof and separated by a thin wall fitting snugly into the slot to removably secure the two members together, said grooves of said first member receiving and snugly fitting longitudinally extending portions of said second member positioned along opposite sides of said wall to further secure the fit between such members, and brush bristles mountedon the end of one of said members opposite, the end thereof secured to the other, the secured ends of said members having a generally plus sign shaped cross-section for im proved manual graspability in manipulation of the brush.

References Cited in the file of this patent UNITED STATES PATENTS D. 163,707 Pifer June 19, 1951 759,490 Yates May 10, 1904 1,131,863 Phillips Mar. 16, 1915 1,233,933 Swartsfager July 17, 1917 1,897,515 Hedstrom Feb. 14, 1933 2,304,319 Saltzman Dec. 8, 1942 FOREIGN PATENTS 83,854 Switzerland June 16, 1920 924,427 France Mar. 10, 1947

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