US 3205757 A
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p 1965 E. H. KUENNEN 3,205,757
THUMB TACK Filed Feb. 11, 1963 INVENTOR.
E H K UENNEN United States Patent 3,205,757 THUMB TACK Edmund H. Kuennen, 6% N. Chestnut Ave., New Hampton, Iowa Filed Feb. 11, 1963, Ser. No. 257,528 1 Claim. (Cl. 85-16) This invention relates to thumb tacks and the like which may be pressed into a surface for securing paper, etc.
It is an object of the present invention to provide a thumb tack which will have a head designed in the proper proportion to fit between the fingers and will substantially reduce the effort in using them as was required in the use of prior art types.
Another object of the present invention is to provide a thumb tack which will have positive grip means in the surfaces of the head thus facilitating easy handling means of the thumb back when desired.
A further object of the present invention is to provide a thumb tack which will have a human engineering quality in its design so as to be universal in its application thus enabling the user to insert it into a surface or remove it from the surface while exerting a minimum of effort in doing so.
Other objects of the invention are to provide a thumb tack bearing the above objects in mind which is of simple construction, has a minimum number of parts, is inexpensive to manufacture and efiicient in operation.
For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:
FIGURE 1 is a perspective view of the present invention;
FIGURE 2 is a view taken on the lines 2-2 of FIG- URE 1; and
FIGURE 3 is an enlarged vertical view of the pointed shaft shown removed from the invention.
Referring to the drawing, a thumb tack made in accordance with the present invention is shown to include an oval base 12 which tapers into a parabolic configuration on the major axis of oval 12, this body comprising the head of thumb tack 10. A pair of opposite concave surfaces 14 along the minor axis of base 12 are provided with a plurality of spaced apart and elongated grooves 16 which provide a means for providing positive gripping with the fingers, particularly when removing tack 10 from a surface. An elongated pin 18 of circular cross sectional configuration molded within the center of thumb tack 10 is provided with a pair of equally spaced apart annular recesses 20 which positively secure the pin 18 within thumb tack 10. Pin 18 is provided with a conical point 22 for easy insertion into a surface.
A person using the thumb tack 10 pinches the surfaces 14 between his fingers and urges the point 22 of pin 18 into the desired surface.
When it is necessary to remove tack 10, the operator pinches the surfaces 14 between his fingers as heretofore described and simultaneously pulls the head which will in turn release the point 22 and while doing so, the fingers will grip into the triangularly configurated grooves 16, thus providing non-slip gripping of the surfaces 14 when removing the thumb tack from the surface.
It will be noted that the pinch grip provided for by the ice concave surfaces 14 of thumb tack 10, in combination with the plurality of triangular configurated grooves 16, thus provides a maximum non-slip grip necessary for removing thumb tack 10 from a surface.
While various changes may be made in the detail construction it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim.
What I claim as new and desire to protect by Letters Patent of the United States is:
A thumb tack comprising in combination a head made from non-metallic plastic, a substantial elongated and conically pointed metallic pin carried by said head pro viding a means for urging said tack into a surface, said head of said tack being substantially oval in configuration at its base and being substantially parabolic at the upper end of said head on the major axis of said base of said head, the side surfaces of said head being substantially concave on the minor axis of said oval base and providing pinch grip means for the fingers of a user when inserting said thumb tack or removing said tack from a surface, said surfaces of said thumb tack being recessed with a plurality of spaced apart and substantially triangularly configurated grooves extending in a direction substantially perpendicular to said pin, the angles formed by the intersections of the groove wall and the concave surface being the inwardly facing angles between the respective walls and said concave surface, said grooves providing a non-slip gripping means for the users fingers by allowing the structure of the users fingers to mold within said grooves and thus imparting a non-slipping grip for urging the said conical pointed pin of said thumb tack into a surface or removing it from a surface, said grooves of said triangular configuration in said concave surfaces sloping towards the top of said head to provide maximum holding for the fingers of the user when pinching upon the concave surfaces of said head for overcoming the hold of said pin within a surface wherein said point of pin is inserted, each of said grooves having an upper wall and a lower wall, the edge between said upper wall and concave surface forming the apex of an angle which is relatively smaller than the angle formed by said lower Wall and said concave surface, said pin being molded centrally within said head and extending through the center of said base of said head when it is molded into said head and the upper end of said pin being provided with a plurality of spaced apart and substantially angular recesses, said recesses providing a means for firmly securing the upper end of said pin within said head and said non-metallic head adhering and filling said recesses of said pin thus preventing said pin from being removed from said head when said thumb tack is being removed from a surface.
References Cited by the Examiner UNITED STATES PATENTS 317,090 5/85 Cave et a1. -28 1,325,721 12/19 Hill 8516 2,314,021 3/43 Sladky 16-121 3,009,382 11/61 Salka 8516 EDWARD C. ALLEN, Primary Examiner.
M. HENSON WOOD, IR., Examiner.