June 3, 1969 R. E. WATSON 3,447,169

ONE-PIECE SINGLE-AXIS FLEXING HINGE FOR TOILET SEATS Filed Nov. 18, 1966 zllll m -r-w ilnll' I"? FIGB INVENTOR ROBERT E. WATSON United States Patent 3,447,169 ONE-PIECE SINGLE-AXIS FLEXING HINGE FOR TOILET SEATS Robert E. Watson, Farmington, Mich., assignor to Swedish Crucible Steel Company, Detroit, Mich., a corporation of Michigan Filed Nov. 18, 1966, Ser. No. 595,433 Int. Cl. A47k 13/12 U.S. Cl. 4-240 2 Claims ABSTRACT OF THE DISCLOSURE The present invention consists of upper and lower hinge leaves joined to hinge posts on a common hinge membrane containing a single pivot axis and formed in a single integral unit from a material which will flex repeatedly for an indefinite number of times without cracking or breaking-for example, from polypropylene plastic. The hinge is molded in a single piece and eliminates hinge pins as well as the cracks between conventional hinge leaves and hinge pins where dirt and corrosive material lodges. The lower hinge leaf portion is secured by fasteners to the underside of the seat or ring and the upper hinge leaf portion 'to the lower side of the cover by similar fasteners. The hinge is fastened to the toilet bowl by threaded studs and nuts, the studs being either of different material seated in the hinge post body during molding or from the same material integral with the hinge post body and molded simultaneously therewith.

Brief summary of invention:

The one-piece single-axis flexing hinge of the present invention is molded in a single body which includes a pair of laterally-spaced hinge post portions into which or onto which hinge post threaded studs are molded. Extending forwardly from the upper forward edges of the hinge posts are lower and upper hinge leaves offset downwardly and upwardly respectively with reference to the hinge membrane by which the leaves are connected to the forward upper edges of the hinge posts. All parts of the hinge are molded simultaneously on a single piece from a suitable plastic capable of indefinite flexing without breakage, such as polypropylene. Tests have demonstrated that this toilet seat hinge membrane will flex indefinitely without breaking and paradoxically the hinge gets stronger in the vicinity of the hinge axis with con-tinned use. This hinge also has no relatively moving parts other than by 0 In the drawings:

FIGURE 1 is a perspective view looking downward from above, of a one-piece single-axis flexing toilet seat and cover hinge according to one form of the invention;

FIGURE 2 is an enlarged right-hand side elevation of the hinge shown in FIGURE 1, attached to the seat" and cover of a toilet seat and to the toilet bowl;

FIGURE 3 is a front elevation of the toilet seat hinge shown in FIGURE 2, with the seat and cover omitted; and

FIGURE 4 is a top plan view of the toilet seat hinge shown in FIGURE 3.

Referring to the drawing in detail, the one-piece singleaxis flexing hinge, generally designated 10, consists of an elongated one-piece body having at its opposite ends upstanding hinge post portions 12 connected by a hinge membrane 14 containing a common pivot axis to forwardly-extending lower and upper hinge leaf portions 16 and 18 respectively. Seated in and extending downwardly from the hinge post portions 12 are threaded studs or stud portions 20 extending downwardly through laterallyspaced holes 22 in the rearwardly-extending platform portion 24 of a conventional toilet bowl 26. The studs 20 may either be of separate material molded into the hinge post body portions 28 or they may be molded integrally and simultaneously therewith from the same material.

The hinge 10 is molded from a flexible plastic material which has the characteristics of being capable of being flexed an indefinite number of times without cracking or breakage along the hinge membrane 14. Such a material is polypropylene plastic which in repeated flexing develops slight upper and lower grooves 15 and 17 along the flexing hinge membrane 14. Paradoxically, the slight thinning resulting from such flexing does not weaken the hinge but, on the contrary, seems to reorient and rearrange the molecules of the material so that the hinge gets stronger rather than Weaker at the hinge membrane 14 containing the common pivot axis with repeated flexing. Moreover, since the hinge pins have been eliminated, along with the bores into which they fit in conventional hinges, alignment errors are eliminated and the costs of production correspondingly lowered, thereby enabling lower selling prices to be set.

The lower and upper hinge leaf portions 16 and 18 have downwardly and forwardly inclined rearward portions 30 and 32 respectively terminating in thereby-offset forwardly-ex-tending lower and upper attachment portions or flanges 34 and 36 respectively. The attachment portions 34 and 36 have flat upper surfaces 38 and 40 respectively and are drilled or molded with laterally-spaced lower and upper holes 42 and 44 respectively through which pass screws or other fasteners 46 into the lower surfaces 48 and 50 of the seat or ring 52 and cover 54 respectively. The body portions 28 of the hinge posts have fiat bottom surfaces 56 molded to fit the flat upper surface 58 of the toilet bowl platform 24. The hinge 10 has no relatively-shiftable parts which in conventional hinges give rise to difiiculties of fitting during installation. Thus, the seat hinge leaf portion 16 is longer than the cover hinge leaf portion 18 and is disposed outboard thereof on the same hinge axis 14, which of course is also the hinge axis of the hinge post 12. The upper hinge leaf 18 is also hinged to the lower hinge leaf 16 along the same hinge membrane 14 (FIGURE 3).

In the operation of the invention, let it be assumed that the lower and upper hinge leaf portions 16 and 18 have been secured to the seat and cover 52 and 54 respectively, and that the threaded studs 20 have been pushed downwardly through the toilet bowl platform holes 22 and secured therein by conventional nuts and washers (not shown). The user raises the cover 54 and seat 52 around the hinge membrane 14 as a pivot axis. Repeated flexing at the pivot axis contained in the hinge membrane 14 causes the plastic to flow so as to develop a shallow groove 15 extending therealong on the upper side thereof, with a similar groove 17 formed on the underside thereof. Where this groove 15 is formed, the material turns white. Thus, the hinge leaf portions 16 and 18 flex along a single hinge membrane 14 containing a single pivot axis, in contrast to prior hinges where the ring or seat and cover have been required to flex along separate axes, with resulting complications of clearance, balance and self-sustaining action in the raised position of the cover 54 and seat or ring 52.

I claim:

1. A single-pivot-axis one-piece toilet seat hinge, comprising:

an elongated one-piece body of indefinitely flexible synthetic plastic material including a pair of laterally-spaced hinge post portions adapted to be secured to a toilet bowl, an elongated lower hinge leaf portion disposed adjacent the forward sides of said hinge post portions and secured thereto at laterally-spaced locations along said lower hinge leaf portion and having a flexible hinge membrane extending between said hinge post portions along a common hinge axis, and an elongated upper hinge leaf portion having its opposite ends disposed inwardly of said hinge post portions and integrally connected by said flexible hinge membrane to said lower hinge leaf portion along said hinge ands. 2. A single-pivot-axis one-piece toilet seat hinge, according to claim 1, wherein said elongated lower and upper hinge leaf portions have seat and cover attachment flanges inclinedly offset downwardly and upwardly respec- 15 4 tively from said flexible hinge membrane containing said hinge axis.

References Cited UNITED STATES PATENTS 2,366,762 1/1945 Watson 4-236 3,019,486 2/ 1962 Stinson. 3,277,500 10/ 1966 Carlson 4-236 LAVERNE D. GEIGER, Primary Examiner.

10 H. J. GROSS, Assistant Examiner.

US. Cl. X.R.