A split-type gasket is disclosed which is free from leakage and requires no increased manhours in assembling, for a large sized gasket made up in ring form with a soft material, such as oil pan gasket. The gasket is provided with a joint connecting end configured by a projecting connector formed in a concentric circle with a bolt hole, and by a mating end having a recess which is so formed as to be fitted by the foregoing projecting end. The joint configuration of a projecting end composed of circular arcs connected in an S-shaped curve, a planar surface and a circular arc, and by a recess which is so formed as to be fitted with the foregoing projecting end is such that the distance between the summit of the projecting end and bolt hole center located near said projecting end is limited to a maximum of 23% of the distance between adjacent bolt holes of the gasket.

BACKGROUND OF THE INVENTION 
The present invention relates to a large-sized split-type gasket in a ring 
shape configuration and made of a soft material. The gasket of the 
invention can be used, for example, as an oil pan gasket applied between 
the contacting surfaces of the cylinder block and oil pan of an engine. 
As is generally known, with regard to a gasket made from a sheet of an 
asbestos containing soft material, for example, the gasket article can be 
punched out at a stroke with a punch die. To reduce the pollution problem, 
a soft material free from asbestos is recommended. However, such 
asbestos-free materials have a high unit price which pushes up the cost of 
the gasket. As a measure taken against this rise in cost, for ring-shaped 
gaskets, attempts have been made to reuse the inside residue which has 
been punched out in ring form. Although, for example, it is known to form 
a gasket into a split type configuration and apply liquid gasket to the 
junctions during assembling, adhering the sections with a lower contact 
pressure allows leaks to arise easily, and is also troublesome, increasing 
the number of manhours required for this job. 
Although the technology to connect a set of split gaskets through a piece 
which has a bolt hole and is formed with a different material is also 
commonly known, a combination of different materials creates special 
problems such as the selection of gasket materials and thickness, control 
of contact pressure and clamping force of bolts, etc., and the presence of 
connecting areas on both sides of the piece leads to the problem of many 
leaking places. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a split-type gasket which 
can be simply constructed without increased manhours and leaks. 
Thus in accordance with a feature of the invention, there is provided a 
split-type gasket having two parallel straight sections and two U-shaped 
sections. Each of said sections has an end connecting means adapted to 
mate with another end connecting means of an adjacent gasket section.

DETAILED DESCRIPTION OF INVENTION 
In achieving the above and other objects, one feature of the present 
invention resides in a split-type gasket 1 made up of a plurality of 
sections 2,3,4 and 5. Two parallel straight sections 2 and 3, and two 
U-shaped end sections 4 and 5, make up the preferred gasket of the 
invention. Each of the ends of each of the sections 2,3,4, and 5 have a 
joint connection which is adapted to fit and mate with the end of the 
adjacent gasket sections. One end of one of the gasket sections is shown 
in FIG. 2 and is a ring shaped from of a soft material; that is, the 
gasket is configured at one end by a ring shaped projecting connector A 
which juts out and and has formed therein a bolt hole as a concentric 
circle 5a and is connected to the remainder of the gasket at shoulders B 
and C. As shown in FIG. 3 the end of the gasket opposite the end shown in 
FIG. 2 has formed therein the recess D which is shaped so as to fit and 
mate with the foregoing jutting portion A. The intermediate projecting 
portions G and H and planar surfaces, E and F are so formed as to fit with 
and mate with shoulders B and C, respectively, of the end of the gasket 
section shown in FIG. 2. 
In another embodiment shown in FIG. 7, the present invention provides a 
split-type gasket having formed therein at one end a connecting section 
having a circular hole 12a and a projecting end which has a jutting out 
portion composed of circular arcs A-1 and B-1 connected in an S-shaped 
curve, planar surface C-1 and circular arc D-1 near the bolt hole 12a. The 
mating end, shown in FIG. 8 has circular arcs G-1 and H-1 corresponding to 
the foregoing circular arcs A-1 and B-1, planar surface K-1 and circular 
arc L-1 corresponding to planar surface C-1 and circular arc D-1, 
respectively, so that distance d between summit T-1 of the foregoing 
jutting portions and the bolt hole center may fall within 23% of the 
distance between adjacent bolt holes of the gasket, and a straight line 
connecting points E-1 and F-1 where the foregoing circular arcs B-1 and 
D-1 intersect either of the inside and outside edges of the ring-shaped 
gasket, respectively does not cross or intersect the bolt hole. This is 
shown in FIG. 7. 
In the split-type gasket having the configuration as described above, a 
connection can simply be made with a gasket of homogeneous material set 
around the bolt hole where the contact pressure is high and stable, and 
since jutting section A and projecting points G and H are linked together, 
fastening by bolt means avoids separation of the junction and reduces the 
leakage problem. 
Also, in the split-type gasket having the configuration as described above, 
since the configuration is made so that distance d between summit T-1 of 
the jutting portions formed in the joint and the bolt hole may fall within 
23% of the distance between adjacent bolt holes of the gasket, the contact 
pressure is sufficient to prevent leakage. In addition, since the 
configuration of the connection section is taken so that the straight line 
connecting points E-1 and F-1 where the foregoing circular arcs B-1 and 
D-1 intersect either of the inside and outside edges of the ring-shaped 
gasket, respectively, may not cross the bolt hole, the distances m and n 
between the bolt hole and circular arcs B-1 and C-1 are sufficient to 
maintain the strength of the connections. And since jutting section A-1 
(FIG. 7) and recess G-1 (FIG. 8) are so configured as to mate with each 
other and thereby be linked together, fastening by means of a bolt through 
bolt hole 12a avoids separation of the stable joint and leakage. 
If the distance d between summit T-1 of the foregoing jutting section A-1 
and the bolt hole center exceeds 23% of the distance between adjacent bolt 
holes of the gasket, the contact pressure of the joint becomes too low and 
leakage is at to arise, and if the straight line connecting the foregoing 
points E-1 and F-1 intersects the bolt hole, distances m and n between the 
foregoing bolt hole and circular arcs B-1 and C-1 decrease and the 
strength of these sections becomes too low, causing breakage, and 
resulting in potential leaking. 
As illustrated in FIG. 1, gasket 1 consists of straight sections 2 and 3 
which are formed as a belt with U-shaped bent sections 4 and 5. The gasket 
is shown to be rectangular, but it can be any convenient shape. In 
addition, straight section 2 and 3 and bent sections 4 and 5 are provided 
with bolt holes 2a, 2b, * * *, 3a, 3b, * * *, 4a, 4b, * * *, and 5a, 5b, * 
* * respectively. These straight sections 2 and 3 and bent sections 4 and 
5 are connected together at joints 6, 7, 8 and 9. 
FIGS. 2 and 3 illustrate making connecting ends of the gasket joints. In 
one of them, shown in FIG. 2, jutting end portion A is formed in a 
concentric circle with bolt hole 5a and smoothly connects to planar edges 
or shoulders B and C with small circular arcs. At a mating end of the 
gasket joint, shown in FIG. 3, D is so formed in a circular arc as to be 
fitted for a mate with jutting portions A and planar surfaces E and F 
smoothly form projecting points G and H to fit into contacting connection 
with shoulders B and C. 
Therefore, once a set of gaskets is used for its intended purpose and is 
placed on the mounting plane with joints 6-9 connected, bolts are fastened 
through bolt holes 2a * * *, 3a * * *, 4a * * *, and 5a * * *, even in 
joints 6-9, no separations arise with jutting section A and projecting 
points G and H linked together. In addition, when the gasket configuration 
is fabricated with homogeneous material the result is a stabilization of 
the contact pressure, causing no leakage. Moreover, in the case of too 
narrow a width of W1 or W2, as illustrated in FIG. 4 and in FIG. 9, which 
is likely to cause a leak, both sides or one side of the bolt hole, as 
illustrated with lines K and K (FIG. 4), and m and m (FIG. 9), may be 
formed in a circular arc. 
Another embodiment of the present invention is illustrated in FIG. 6, 
wherein gasket 11 consists of straight sections 12 and 13 which are formed 
into a belt configuration with U-shaped bent sections 14 and 15. In 
addition, straight sections 12 and 13 and bent sections 14 and 15 are 
provided with bolt holes 12a, 12b, * * *, 13a, 13b, * * *, 14a, 14b, * *, 
and 15a, 15b, * * *, respectively. These straight sections 12 and 13 and 
bent sections 14 and 15 are connected together at joints 16, 17, 18 and 
19. 
FIGS. 7 and 8 exhibit these connecting junctions, and for example near bolt 
hole 12a which forms joint 17, there is a jutting out section formed by 
circular arcs A-1 and B-1 which are connected together in a S-shaped form, 
planar surface C-1 and circular arc D-1. And distance d between summit T-1 
of the jutting section and the center of bolt hole 12a is so formed as to 
fall within 23% of the distance P between adjacent bolt holes of the 
gasket (for example, if p=80 mm, and ratio=20%, then: d=16 mm). In 
addition, chain line X connecting points E-1 and F-1 where circular arcs 
B-1 and D-1 intersect the outside or inside of the gasket is so formed as 
not to cross or intersect bolt hole 12. 
As shown in FIG. 8 the corresponding recess is so formed as to make 
circular arcs G-1 and H-1, planar surface K-1 and circular arc L-1 fit 
into the foregoing circular arcs A-1 and B-1, planar surface C-1 and 
circular arc D-1, respectively. 
Therefore, once the gasket is placed on the mounting plane with joints 
16-19 connected, bolts are fastened through bolt holes 12a * * *, 13a * * 
*, 14A * * *, and 15a * * *, even in joints 16-19, the jutting section and 
recess as linked will not separate, and since the contact pressure is 
sufficient and the junction is formed of homogeneous material, no leakage 
problems will arise. 
In the event that too narrow a width of section W1 or W2 occurs, as 
illustrated in FIG. 9, which is likely to cause a leak and/or gasket 
breakage, both sides or one side of the bolt hole may be formed in a 
circular arc, as illustrated with chain lines M and M. 
The gasket of the present invention, having the configuration as explained 
above, causes no leakage even without liquid gasket sealing means thereby 
resulting in uninflated manhour labor costs and low material costs as well 
as improvement in yield of acceptable product. 
It will be understood that any suitable gasket material can be used for 
purposes of the invention. 
Further variations and modifications of the foregoing will be apparent to 
those skilled in the art and are intended to be encompassed by the claims 
appended hereto.