Waterproofing device for screw-tightened connectors

A pair of threaded-connection type connectors in which male and female connectors are mutually coupled to each other by engagement of a bolt provided in the male connector and a nut provided in the female connector, comprises a cylindrical sleeve extending from the male connector in a direction opposite to a connecting portion with the female connector, and a grommet for watersealingly covering the male connector except for the connecting portion thereof. The grommet includes an opening tightly fitted an outer cylindrical surface of the sleeve so that the bolt can be rotated without removing the grommet from the male connector and the grommet can define the waterproofed space therein together with the sleeve.

BACKGROUND OF THE INVENTION 
The present invention relates to a device for waterproofing a pair of 
mutually screw-tightened connectors, and more particularly relates to a 
device for waterproofing a pair of mutually screw-tightened multi-terminal 
connectors which can be easily coupled to each other. 
FIG. 6 shows a device for waterproofing a pair of mutually screw-tightened 
connectors 35 and 43. The device includes waterproofing rubber rings 40, a 
rubber grommet 41, and another rubber grommet 50. The connector 35 is 
secured to a panel 36 by screws 37. The secured connector 35 includes 
terminals chambers 38, and a nut 42. The waterproofing rubber rings 40 are 
fitted on electric wires 39 and inserted in the terminal chambers 38. The 
rubber grommet 41 is fitted on the housing of the secured connector 35 at 
the electric wire outgoing end 51 of the housing to prevent water from 
entering into the connector. The nut 42 is secured in the secured 
connector 35. The other connector 43 is adapted to be fitted to the 
secured connector 35. The fitted connector 43 includes a bolt 44, stoppers 
45 and 46, and an electric wire holding plate 48. The bolt 44 is 
screw-engaged in the nut 42 so that the connectors 35 and 43 are coupled 
to each other. The head 47 of the bolt 44 is located at the outer portion 
of the fitted connector 43. The stoppers 45 and 46 are provided on the 
bolt to prevent it from moving in the axial direction thereof relative to 
the housing of the fitted connector 43. The other grommet 50 is fitted on 
the housing of the fitted connector 43 at the electric wire outgoing end 
49 of the housing to prevent water from entering into the connector. 
When the screw-tightened connectors 35 and 43 are to be either coupled to 
or uncoupled from each other, it is necessary to remove the waterproofing 
grommet 50 from the fitted connector 43 in order to turn the bolt 44. For 
that reason, it is troublesome to either coupled or uncoupled the 
connectors 35 and 43 to or from each other. This is a problem. Besides, 
since the grommet 50 is removed from the fitted connector 43 in order to 
turn the bolt 44, the rubber rings 40 need to be provided in the terminal 
chambers 38. For that reason, the diameter of each of the connector 
housing 35 and 43 is made large. This is also problem. 
SUMMARY OF THE INVENTION 
The present invention was made in order to solve the above-mentioned 
problems. 
Accordingly, it is an object of the present invention to provide a device 
which is for waterproofing a pair of mutually screw-tightened connectors 
and is such that a grommet does not need to be removed from the 
corresponding connector in order to either couple or uncouple the 
connectors to or from each other, and waterproofing rings, the presence of 
which would increase the sizes of the connectors, do not need to be 
provided therein. A bolt is provided in one of the connectors and extends 
along the total length of the connector. A nut is provided in the other of 
the connectors. The bolt is screw-engaged in the nut so that the 
connectors are coupled to each other. The connectors are covered with 
covering means of the waterproofing device so that the connectors are 
waterproofed. The device is characterized in that the housing of the 
connector provided with the bolt is formed with a cylindrical sleeve 
surrounding the shank of the bolt; the covering means for the connector 
provided with the bolt has an opening in which the sleeve is tightly 
fitted for waterproof sealing; and a waterproofing seal means is provided 
on the bolt. In addition, it is possible that engagement flanges are 
provided on the housings of the connectors, the peripheral portions of the 
covering means are fitted on the flanges, and the outer surfaces of the 
peripheral portions are tightly fitted on a panel to which one of the 
connectors is secured. Since the bolt can be directly turned outside the 
opening of the covering means without removing it from the connector, the 
connectors can be efficiently coupled to and uncoupled from each other. 
Since the covering means does not need to be removed from the connector, 
the waterproofing rings do not need to be provided in the connectors. For 
that reason, the connectors can be made compact. Since the connectors are 
completely covered with the covering means, the waterproofing property of 
the device is high.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Embodiments of the present invention are hereafter described in detail with 
reference to the drawings attached hereto. 
FIG. 1 shows a device which is one of the embodiments and is for 
waterproofing a pair of mutually screw-tightened connectors 1 and 23. The 
device includes elastic rubber grommets 13 and 31, an O-ring 11, and tapes 
(not shown). The connector 1 is a fitted one, and includes a bolt 2, a 
housing 5, a cylindrical sleeve 8, a ring groove 10, and an engagement 
flange 19. The other connector 23 is a secured one, and includes a nut not 
shown in the drawings, a housing 24, and an engagement flange 27. The 
connector 23 is secured to a panel 26. 
The bolt 2 for coupling the fitted and the secured connectors 1 and 23 to 
each other extends at the central portion of the fitted connector 1 along 
the total length thereof so that the head 3 of the bolt is located outside 
the grommet 13, the housing 5 is made of a synthetic resin, and formed 
with the cylindrical sleeve 8 at the electric wire outgoing end 6 of the 
housing so that the sleeve surrounds the shank 7 of the bolt 2 and the 
head 3 of the bolt is exposed outside the sleeve, as also shown in FIG. 2. 
The portion 9 of the shank 7 of the bolt 2, which is located in the 
housing 5 of the fitted connector 1 has the ring groove 10 in which the 
O-ring 11 is fitted to serve as a waterproofing seal between the bolt and 
the inside surface 12 of the housing of the connector. 
The elastic rubber grommet 13, which covers the electric wire outgoing side 
of the fitted connector 1, has a circular hole 14 having a diameter 
slightly smaller that the outside diameter of the cylindrical sleeve 8, 
and includes an annular boss 15 around the hole, and a peripheral portion 
16 having an inward part 17. The engagement flange 19 is provided on the 
intermediate portion of the peripheral surface 18 of the housing 5 of the 
fitted connector 1 so that the flange is engaged on the inside surface of 
the inward part 17 of the peripheral portion 16 of the grommet 13. After 
electric wires 4 and 4' are taken out from the grommet 13 through the 
tubular portion 21 thereof, the cylindrical sleeve 8 of the fitted 
connector 1 is inserted into the hole of the grommet and the inward part 
17 of the grommet is fitted on the engagement flange 19 so that waterproof 
sealing is performed on the sleeve, the grommet, the inward part and the 
flange. One of the tapes is wound on the electric wires 4 and 4' and the 
tubular portion 21 of the grommet 13 at the electric wire outlet port 22 
thereof so that waterproof sealing is performed on the wires and the 
tubular portion. 
The engagement flange 27 of the secured connector 23 is provided on the 
peripheral surface 25 of the housing 24 Of the connector near the panel 26 
so that the flange projects from the peripheral surface. Hooks 29 for 
securing the connector 23 to the panel 26 are formed on the engagement 
flange 27 and project therefrom so that the hooks are fitted in the 
engagement holes 28 of the panel to secure the connector thereto. The 
engagement flange 27 is reinforced by props 30. The inward part 33 of the 
peripheral portion 32 of the grommet 31 is fitted on the engagement flange 
27 at the periphery thereof. The grommet 31 covers the secured connector 
23. The other of the tapes is wound on electric wires and the grommet 31 
at the electric wire outgoing port 34 thereof so that waterproof sealing 
is performed on the wires and the grommet. 
As shown in FIG. 3, the fitted and the secured connectors 1 and 23 are 
coupled to each other by engaging the bolt 2 of the fitted connector in 
the nut of the secured connector. Since the head 3 of the bolt 2 is always 
located outside the grommet 13, the bolt can either engaged in the nut and 
tightened or loosened and disengaged therefrom as the grommet remains 
fitted on the fitted connector 1. To couple the connectors 1 and 23 to 
each other, the fitted connector is inserted into the secured connector 
and the bolt 2 is engaged in the nut and tightened so that connectors are 
pulled toward each other such that the outer surfaces 16a and 32a of the 
peripheral portions 16 and 32 of the grommets 13 and 31 are respectively 
placed in tight contact with the sides 26a and 26b of the panel 26. As a 
result, the connectors 1 and 23 are completely sealed by the grommet 13 
and 31. 
FIG. 4 shows a waterproofing device which is a modification of the 
embodiment shown in FIGS. 1, 2 and 3. As for the device, the engagement, 
or outward, flange 19, of a fitted connector 1' is made as large in size 
as the flange 27 of a secured connector 23, and a grommet, or cover, 13' 
for the fitted connector is made so large in size that the engagement 
holes 28 of a panel 26 are located inside the grommet to prevent water 
from entering into the device through the engagement holes. The grommet 
13' includes an inward flange 91 disposed between the engagement flange 
19' and the panel 26. As a result, the connectors 1' and 23 are more 
completely sealed by the device than by the device shown in FIGS. 1, 2 and 
3. 
FIG. 5 shows a device which is another embodiment of the present invention 
and is for waterproofing a pair of mutually screw-tightened connectors 53 
and 57. The device includes a waterproofing cover 52 made of a synthetic 
resin, a seal member 61, a seal ring 67, and an elastic rubber grommet 72. 
The fitted connector 53 includes a housing 54, a cylindrical sleeve 55, a 
step 56, a bolt 59, and terminals 74. The cylindrical sleeve 55 is formed 
on the central portion of the housing 54. The step 56 is formed on the 
inside of the sleeve 55. The bolt 59, which is engaged in the nut 58 of 
the secured connector 57, is rotatably fitted in the step 56. The seal 
member 61 is provided on the shank 81 of the bolt 59 between the head 60 
thereof and the step 56 and fitted in the annular groove 62 of the inside 
surface of the cylindrical sleeve 55 so that the seal member is held by 
engagement projections 63 provided over the groove. The upper annular 
portion 64 of the waterproofing cover 52, which has a hole 82, is tightly 
fitted on the outside surface of the cylindrical sleeve 55. In addition, 
the waterproofing cover 52 includes a wrap member substantially L-shaped 
in cross section, one end of which is integrally formed on a tip end of 
the upper annular portion 64, and the other end of which sealingly 
contacts the seal member 61, so that the waterproof property is attained 
between the outer surface of the sleeve 55 and the inner surface of the 
upper annular portion 64. 
The secured connector 57 includes the nut 58, securing hooks 76, terminals 
77, and a cover 79. 
The seal ring 67 made of polyurethane or the like is fitted in a seal 
groove 66 provided in the waterproofing cover 52 at the peripheral portion 
65 thereof, and is kept in tight contact with the surface of a panel 68 to 
which the connector 57 is secured. Props 70 are appropriately provided on 
the outer circumferential surface 69 of the waterproofing cover 52, and 
extend from the top of the cover toward the bottom thereof. The rubber 
grommet 72 is fitted in the electric wire hole 71 of the cover 52. 
Electric wires 73 are connected to the terminals 74 housed in the housing 
54 of the filed connector 53 and not provided with a waterproofing means 
on the terminals, and are taken out from the cover 52 through the electric 
wire hole 71 thereof. When the securing hooks 76 of the secured connector 
57 are fitted in the engagement holes 75 of the panel 68 to secure the 
connector thereto, the terminals 77 of the connector are connected to 
those 74 of the fitted connector 53 so that electric wires 78 connected to 
the terminals 77 extend out from the secured connector through the cover 
79 thereof. The engagement holes 75 of the panel 68, the terminals 74 of 
the fitted connector and the mutually coupled portions 80 of both the 
connectors 53 and 57 are sealed together by the waterproofing cover 52. 
When the bolt 59 of the fitted connector 53 is either engaged in the nut 58 
of the secured connector 57 and tightened therewith to couple the 
connectors to each other or loosened and disengaged from the nut to 
uncouple the connectors from each other, the waterproofing cover 52 does 
not need to be removed from the fitted connector. For that reason, 
waterproofing rubber rings such as those 40 shown in FIG. 6 and a seal 
member do not need to be provided on the terminals 74 of the fitted 
connector 53 and the mutually coupled portions 80 of the connectors 53 and 
57, respectively, and the connectors can be therefore made compact. 
The present invention is not confined to the embodiments described above, 
but may be embodied or practiced in other various without departing the 
spirit or essential character of the invention.