1. Field of the Invention
This invention relates to a rotary connector device which is provided, for example, around a steering of an automobile so as to effect a power supply, etc., while absorbing the rotation of the steering by bending and rotating flat harnesses.
2. Related Art
FIG. 4 shows one conventional rotary connector device (see JP-A-10-64646 Publication).
This rotary connector device 61 is provided in the vicinity of a steering (steering wheel) 62, and comprises an annular rotary cover 64 fixed to a steering shaft 63, an annular fixed cover 65 which is disposed around the outer periphery of the steering shaft 63, and is fixed to a combination switch 69, and a flexible flat harness 67 which is disposed in a generally spirally-wound condition within an annular (doughnut-shaped) space 66 formed by the two covers 64 and 65.
Rollers 68 are rotatably provided within the annular space 66, and the flat harness 67 is circumferentially disposed in contiguous relation to an inner peripheral wall of the rotary cover 64 at the inner side of the rollers 68, and is also circumferentially disposed in contiguous relation to an outer peripheral wall of the fixed cover 65 at the outer side of the rollers 68. One end of the flat harness 67 is connected at the rotary cover-side to an air bag device, a horn, etc., provided within the steering wheel, while the other end of the flat harness 67 is connected at the fixed cover-side to a power source, etc.
FIG. 5 shows an internal structure of a fixed cover of another conventional rotary connector device (see JP-A-2001-28286 Publication).
The fixed cover 70 includes a disk-like wall portion 72 having a hole 71 formed through a central portion thereof, and an annular outer peripheral wall 73 formed at an outer peripheral edge of the disk-like wall portion 72. This fixed cover 70 has a harness guide wall 74 extending in contiguous relation to an inner surface of the outer peripheral wall 73 in a peripheral direction thereof. A flexible flat harness 75 is introduced from the exterior into the inside of the fixed cover 70 through a gap between the guide wall 74 and the outer peripheral wall 73. The flat harness 75 comprises a plurality of parallel conductor portions 75a, and a sheet-like insulating portion 75b covering these conductor portions 75a. 
However, with respect to the conventional rotary connector device having the fixed cover 70 shown in FIG. 5, in the case where with an increased number of connection circuits, two flat harnesses 75 are used in a superposed manner as indicated by broken lines, the two flat harnesses 76 are pulled in accordance with the rotation of a rotary cover, and contact a distal end 74a of the guide wall 74. In this case, particularly when this contact pressure is excessive, there has been a fear that the two flat harnesses 75 are broken or cut, so that the short-circuiting between the two flat harnesses 75 occurs, thereby causing wrong operations of associated electrical equipments, etc.
USPTO Backgrounds
USPTO Backgrounds