Swing door hinge

A swing door hinge is provided comprising a first hinge member having a projection of approximately rectangular block shape and provided with at least two engaging recesses, the first hinge member being intended to be mounted to either a wall frame or a swing door, and a second hinge member having at least two engaging arms inserted into respective engaging of the first hinge member for pivotal movement and guide openings provided in the engaging arms. The second hinge member, which is also intended to be mounted to the wall frame or the swing door whichever does not carry the first hinge member, has pivot pins mounted in the guide openings and yieldingly urged by respective springs in the inward direction. Each pivot pin is inserted at its front end into a respective engaging recess of the first hinge member and pivotably mounted to a shaft which is installed in such a position of the projection that the distance thereof from the front end of the projection is smaller than the distance thereof from each side end of the projection.

BACKGROUND OF THE INVENTION 
The present invention relates to a swing door (FIGS. 16-18) hinge for 
pivotal movement of a swing door. 
A known hinge construction for a swing door comprises an upper pin means A 
and a lower pin means B which both are arranged so that the co-axis of 
their respective pins P, P extends at a small angle to the side of a door 
C. The upper pin means A has a pair of support elements D, D arranged in 
symmetry about the pin P and extends across the opening provided in a 
support plate E. The support plate E also has a recess F formed therein on 
both sides of the opening for accepting the two support elements D, D so 
that the door C can securely be sustained at a given position with the two 
support elements D, D resting in the recess F by means of a gravity. 
Hence, such a conventional swing door hinge has to be placed at a precise 
location on the door and also, its upper and lower pin means need to be 
separately mounted to their respective positions, adjacent to the 
corresponding corners of a door opening, on a door jamb frame, whereby the 
installation of a swing door(s) will be troublesome and claim more time 
and labor to be done. 
Also, it is quite difficult for the arrangement of any known swing door 
hinge to allow a door to return to the original closed position 
automatically once the door has widely been opened more than 90 degrees to 
the frontward or backward. 
SUMMARY OF THE INVENTION 
The present invention is thus oriented, in view of the foregoing 
disadvantages, towards an improved swing door hinge which can be installed 
with ease and automatically return to the original closed position when a 
door has been opened up to more than 90 degrees in either the frontward or 
backward direction. 
The foregoing and other objects and the novel aspects of the present 
invention will completely be apparent from the following detailed 
description in conjunction with the accompanying drawings. 
It should be understood that the drawings are provided for ease of 
description and will not limit the scope of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of the present invention will be described in more 
detail with reference to the accompanying drawings. 
FIGS. 1 to 12 illustrate a primary embodiment of the present invention. As 
shown, a pair of swing doors 1, 1 provided in the opening of a building 
structure for opening and closing movements are pivotably mounted by a 
plurality of hinges-namely, two pairs of upper and lower hinges 3, 3, 3, 3 
in this embodiment-to two wall frames 2, 2 respectively which are in turn 
fixed at both sides of the opening. 
Each swing door hinge 3 comprises a first hinge member 4 of synthetic resin 
material mounted to the wall frame 2, a shaft 5 fixedly mounted to the 
first hinge member 4 so that the distance Y (FIG. 11) from the front end 
of the hinge member 4 to the axis of the shaft 5 is smaller than the 
distance X between each side end of the first hinge member 4 and the axis 
of the shaft 5, a couple of pivot pins 6, 6 mounted on the shaft 5 for 
pivotal movement, a second hinge member 7 of synthetic resin material 
mounted to the swing door 1 for coupling to the first hinge member 4 by 
the two pivot pins 6,6 inserted therein, and a couple of springs 8, 8 
interposed between the second hinge member 7 and their respective pivot 
pins 6, 6 for yieldingly urging the second hinge member 7 towards the 
first hinge member 4. 
As best shown in FIGS. 5 to 7, the first hinge member 4 consists mainly of 
a first hinge body 10 provided at corners with insertion holes 9, 9, 9, 9 
for accepting e.g. screws, a projection 13 extending from the surface of 
the first hinge body 10 and having a front side thereof arranged flat and 
both side corner portions 12, 12 thereof enlarged outwardly, a couple of 
engaging recesses 11, 11 arranged adjacent the projection 13, and a 
fitting bore 14 provided in a center region of the projection 13, where 
the distance Y is smaller than the distance X, for allowing the shaft 5 to 
extend therein across the engaging recesses 11, 11. 
The pivot pin 6 is formed of a metal material, as shown in FIG. 3, having a 
through hole 15 provided in one end thereof, through which the shaft 5 can 
extend, and a thread 16 arranged in the other end. 
The thread 16 of the pivot pin 6 is screwed in a retainer nut 18 provided 
with a spring stopper 17 for supporting one end of the spring 8. 
As shown in FIGS. 8 to 10, the second hinge member 7 consists mainly of a 
second hinge body 19 arranged in a channel shape for holding the swing 
door 1 and coming into surface contact with the flat side of the 
projection 13 of the first hinge member 4, a couple of engaging arms 20, 
20 formed on the back of and integrally with the second hinge body 19 for 
engagement with the respective engaging recesses 11, 11 of the first hinge 
member 4, a couple of guide openings 21, 21 provided therein for accepting 
the pivoting pins 6, 6, and insertion holes 22, 22, 22, 22 arranged in the 
sides of the second hinge body 19 for fastening with e g. screws. A slot 
30 is formed through each engaging arm 20 (FIG. 10). The shaft 5 is 
received in the slot 30, which permits movement of the second hinge member 
7 radially with respect to the shaft 5. 
For coupling, the pivot pins 6, 6 are inserted at one end into the recesses 
11, 11 and secured with the shaft 5 which extends through the fitting bore 
14 of the projection 13 and the through holes 15, 15 of the respective 
pivoting pins 6, 6. The shaft 5 is secured at both ends for preventing 
removal of the shaft 5 from the fitting bore 14. 
Then, the pivot pins 6, 6 are inserted at the other end into the guide 
openings 21, 21 of the second hinge member 7 and the springs 8, 8 are 
fitted onto the pivot pins 6, 6 which both extend inwardly of the second 
hinge member 7. The nuts 18, 18 are screwed onto the threads 16, 16 of 
their respective pivot pins 6, 6 and locked when the springs 8, 8 yield a 
given tension. 
The nuts 18, 18 may be locked by double nut fastening or tightened with the 
use of set bolts. 
Each swing door hinge 3 assembled in the foregoing manner is now fixed for 
installation of the swing doors 1, 1 in the building opening by fastening 
with appropriate screws 23 the first hinge member 4 to the wall frame 2 
and the second hinge member 7 to the swing door 1. 
In operation, the tension of the springs 8, 8 is increased in proportion to 
the opening angle of the swing door 1 when the opening and closing 
movement either to the frontward or to the rearward is through 90 degrees, 
as shown in FIG. 11. Hence, when the swing door 1 is released at any 
angle, it will be returned by the yielding force of the springs 8, 8 back 
to the original position where the first and second hinge members 4 and 7 
come in contact with each other at the flat interface. 
In other words, the swing doors 1, 1 are returned to the closing position. 
When the swing door 1 is turned to more than 90 degrees in either the 
frontward or rearward direction, the yielding force of the springs 8, 8 
then intends to urge the swing door 1 towards the opening direction and 
will hold the same in the open state (as shown in FIG. 12). 
Other embodiments of the present invention will now be described referring 
to FIGS. 13 to 15, in which like components are represented by like 
numerals as illustrated in the previous embodiment and not explained 
again. 
A first alternative embodiment is portrayed in FIG. 13, in which the 
difference from the previous embodiment resides in the pivot pins 6, 6 
being urgingly mounted in a first hinge member 4A. Accordingly, a swing 
door hinge 3A of this embodiment will act equivalent to the previous 
embodiment. 
Also, a further embodiment shown in FIGS. 14 and 15 is differentiated from 
the previous embodiments by providing in combination a first hinge member 
4B including projection 13 having three engaging recesses 11, 11, 11 
arranged therein, a second hinge member 7A provided with three engaging 
arms 20, 20, 20 which are in turn inserted into the corresponding engaging 
recesses 11, 11, 11 of the first hinge member 4B, and three of the pivot 
pins 6, 6, 6, all of which constitutes a swing door hinge 3B. Like the 
previous embodiment, this arrangement of the swing door hinge 3B will be 
used with equal success. 
Although the first and second hinge members 4 and 7 are formed of a 
synthetic resin material throughout the embodiments, they may be 
fabricated by any other appreciable material. 
As apparent from the above description, the present invention will provide 
the following advantages. 
(1) The shaft, on which the pivot pins urgingly installed between the first 
and second hinge members are pivotably mounted, is located at such a 
position in the rectangular projection of the first hinge member that its 
distance from the front end of the projection is smaller than its distance 
from the side ends of the projection, whereby the swing door can be turned 
more than 90.degree. in swing action to both the frontward and the 
rearward. 
More specifically, the swing action of the swing door will be almost 
doubled in distance of movement. 
(2) The pivot pins are provided for sliding along the guide openings in the 
second hinge member so that the second hinge member can move axially of 
the pivot pins and perform a pivotal action when the swing door is turned 
in swing motion. Accordingly, the first and second hinge members will be 
protected and free from unwanted dirt or obstacles. 
(3) The first and second hinge members are fixedly secured to the wall 
frame and the swing door respectively with screws or the like, whereby the 
installation of the doors will be carried out with ease by the same 
procedure as of conventional hinges. 
(4) The yielding force of the springs is controlled by adjusting the 
location of the spring stopper of the nut screwed onto each pivot pin and 
thus, will arbitrarily be determined. 
(5) The first and second hinge members are formed of synthetic resin 
material and will thus be fabricated with lower cost in industrial 
production. 
(6) The first and second hinge members are substantially composed of pivot 
pins, a shaft, and springs, and thus, are of a minimum number of necessary 
components, forming a simple arrangement.