MXPA97005329A - Rotary connector - Google Patents

Abstract

A moving member 5 provided with first and second openings 14, 15 is disposed in a holding space 10 formed between a fixed housing 1 having an outer cylindrical wall 6 and a movable housing 2 having an inner cylindrical wall 7 such that the moving member may circularly move;and width W1 of the first opening 14 and width W2 of the second opening 15 are set so that W1 W2. In the holding space 10, first and second flat cables 3, 4 having both ends thereof fixed to the peripheral surfaces of the outer cylindrical wall 6 and the inner cylindrical wall 7 are wound, and reversal sections 3Ý, 4Ýof the flat cables 3, 4 are passed through the first opening 14 and the second opening 15. The inner end of the first flat cable 3 is directly wound around the peripheral surface of an inner cylindrical section 9 of the first flat cable 3, while the inner end of the second flat cable 4 is wound around the inner cylindrical section 9 via about one turn of the first flat cable 3 so that the flat cables 3, 4 have different winding diameters relative to the inner cylindrical section 9.

Description

ROTATING CONNECTOR BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a rotary connector incorporated in an automotive steering unit and used, for example, as an electrical connection in a device with a air bag mounted on a steering wheel of a motor vehicle and a arrangement of associated control circuits mounted on a car body. More particularly, the present invention relates to a rotating connector in which the planoe cables are stored in a containment space formed between a fixed housing and a mobile housing, wherein the flat cables are wound in opposite directions to through portions of reversal in U form.

Description of the prior art. A rotary connector includes a fixed housing, a mobile housing that is rotatably connected to the fixed housing, and a flat cable stored in a containment space formed by the fixed housing and the moving housing. The flat cable has a first end connected to a joint (connector) mounted on a fixed housing, and a second end connected to a joint mounted on a mobile housing. The rotary connectors are incorporated into an automotive steering unit and are used, for example, to provide an electrical connection between an air bag inflator attached to a steering wheel of a car, which can be rotated a finite number of revolutions, and an arrangement of cotrol circuits associated and mounted on a car body. The flat cable is configured as a band and supports a multitude of parallel conductors that < -, e extend between the first and second ends. Two types of rotary connectors are commonly used: in the first type, the flat cable is wound in a single direction (i.e., clockwise or counterclockwise) to form a coil, and the second type , the flat cable is partially wound in a first direction, then inverted through a U-shaped reversion portion and partially wrapped in the opposite direction. In the rotary connector of the second type (reversing), the required length of the flat cable is significantly reduced with respect to that needed for the rotating connector of the second type (in coil). Reversing type rotary connectors typically use a flat cable with the multitude of conductors arranged in parallel. As the number of conductors increases to meet a recent trend toward multi-circuit applications, a problem arises in that the width of the flat cable must inevitably increase to support more conductors, thereby increasing the size of the rotating connector. A solution to this problem is incorporated into the gyrotope connector described in the U.S. Patent. No. 3, 763, 455, which supports multiple-circuit applications using two ribbon cables to accommodate conductors. Figure 4 is a top plan view-illustrative of a schematic configuration of a rotating connector described in the U.S. Patent. No. 3, 763, 455. A movable housing 101, having a cylindrical inner section, is rotatably connected to a fi xing housing 100 having a cylindrical outer * section. A first flat cable 103 and a second flat cable 104 are housed in an annular containment space 102 formed between the fixed housing 100 and the moving housing 101 these flat cables 103 and 104 are stored in the containment space 102 so that they are wound in a first direction (counterclockwise) around the outer cylindrical section of the fi xing housing 100, and in a second direction (clockwise) around the lower cylindrical section of the housing 101. In the position in which the winding direction is reversed, the U-shaped reversion portions 103a and 104a are formed. The inner ends of the flat cables 103 and 104 are connected to the outlet sections 107 and 108 of the cablesa located adjacent the inner cylindrical section of the moving housing 101. The outer ends of the two flat cables 103 and 104 are connected to the exit sections 109 and 110 of the cables located adjacent to the outer cylindrical section of the fi xing housing 100. Furthermore, disposed in the containment space 102 are the groups of first and second rollers 105 and 106 arranged in circumferential direction, the reversing portion 103a of the first flat cable 103 being bent around the first group of rollers 105, and the reversing portion 104a of the second flat cable 104 being bent about the second group of rollers 106. In the rotary connector thus configured, when, for example, the movable housing 101 is rotated in the clockwise direction of the clock (with respect to the fi xing housing 100 in FIG. 4), the reversing portions 103a and 104a of the flat cables 103 and 104, respectively, move in the direction of the clockworks in the containment space 102 for a amount that is smaller than that of the mobile housing 101, causing the flat cables 103 and 104 to be wound onto the inner cylindrical section of the moving housing 101. Conversely, when the moving housing 101 is rotated in the opposite direction clockwise in Figure 4, the reversion portions 103a and 104a of the flat cables 103 and 104, respectively, also move counterclockwise by an amount that is smaller than that of the housing movable 101, causing the flat cables 103 and 104 to unroll from the outer cylindrical section of the fi xing housing 100. At the time of such winding and unwinding, the roller groups 105 and 106 are moved they also come in the same direction in response to the forces applied by the reversion portions 103a and 104a of the flat cables 103 and 104, respectively. In the conventional rotary connector described above, the radial deformation of the two cables L03 and 104 is restricted by the groups of rollers 105 and 106. Therefore, the flat cables 103 and 104 can move smoothly in the circumferential direction of the containment space 102. However, since the roller groups 105 and 106 are arranged in the containment space 102 so that they are spaced apart from each other, the vibrations applied to the rotary connector cause the groups of rollers 105 and 106 to collide with one another. against another, producing a collision noise. Another problem associated with this rotary connector is that it is difficult to assemble the roller groups 105 and 106 on the rotary connector. An alternative arrangement that attacks the problem described above is shown in Figure 5. In this structure, instead of employing the mutually separate roller groups 105 and 106, a mobile member 111 is movably disposed in the containment space 102 that has the at least two openings Illa and IIIb, and the reversing portions 103a and 104a of the flat cables 103 and 104 are passed through the openings Illa and IIIb. The mobile member III is composed of an annular rotating plate 11? and a set of rollers 113 rotatably connected to the turntable 112. The openings Illa and III are formed at equal intervals between the groups of rollers 113. Therefore, when the movable member 111 having such openings Illa and IIIb is employed, the turntable 111 and the rollers 113 can be mounted to the rotary connector during assembly as a piece, and the collision between the rollers is prevented, thus solving the aforementioned problems with respect to the conventional rotary connector. However, the rotary connector shown in Figure 5 poses different problems that are described below. Referring again to Figure 5, the diameter of the inner cylindrical section of the movable housing 101 is denoted as D, and the thickness of each of the flat cables 103 and 104 is denoted co or t. With this diepoeition, the winding diameter of the first flat cable 103 wound directly on the inner cylindrical section is O, while the winding diameter of the second flat cable 104 wound on the inner cylindrical section through the first flat cable 103 is (D «2t). Therefore, the winding diameters of the two cables planoe 103 and 104 do not match. Accordingly, when the movable housing 101 is rotated, the amount of winding of the flat cable 1032 over the inner cylindrical section is different from that of the flat cable 104, or the amount of unwinding of the two flat cables thereof is different. , thus making the reversion portion 104a of the second planar cable 104 which has the largest winding diameter move more rapidly than the reversion portion 103a of the first planar cable 103 having a smaller winding diameter. As a result, as shown in Figure 5, when the flat cables 103 and 104 are developed from the inner cylindrical section - and rolled upside down on the outer cylindrical section, the reversion portion 104a of the second flat cable 104 contacts the roll 113 located at the end of the opening lllb, while the reversing portion 103a of the first wire 103, which is moving slowly, moves merely in the opening Illa and does not contact the roll 113, presenting a problem in the sense that the mobile member 111 can not be moved smoothly by the forces applied by the two reversal portions 103a and? 4a.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a rotating connector that includes a movable member disposed of a containment space that is provided with a set of openings through which the reversion portions of a multitude of flat cables pass where the width of a of the openings in the circumferential direction is determined so that it is smaller than the other. In this way, instead of adjusting all openings of the movable member to the same width, the opening corresponding to the reversion portion of the flat cable having a smaller winding diameter is adjusted smaller than that of the opening corresponding to the portion of reversion of the flat cable having a larger diameter so that the movable member moves smoothly in the containment space because the forces of the reversal portions of the flat cables are applied respectively to the movable member. According to the present invention, a rotatable connector includes a first housing having an outer cylindrical section, a second housing which is rotatably fixed to the first housing and which has an internal cylindrical section opposite to the cylindrical section. outside so that an annular space of containment is formed therebetween, a multitude of flat cables that are wound in the containment space so that the reversion portions and other ends of the same are formed eetán fixed respectively to the section outer cylindrical and inner cylindrical section, and a movable member which is disposed in the containment space so as to rotate with respect to the fixed housing and having a multitude of openings through which pass the reversion portions of the housing. flat cables, where the width of one of the openings (measured in circumferential direction) is smaller than the width of the other openings. ras The movable member functions to prevent the flat cables from being deformed in the radial direction within the containment space. The movable member can be constructed, for example, by means of a set of rollers connected rotatably to a rotating plate. In that structure, the openings are formed between adjacent pairs of rollers. Some of the pens can be replaced by fixed cylinders so that each opening is formed between a fixed cylinder and an adjacent roller. If there is N (where N is a whole number) flat cables, it is then necessary to provide the mobile member with N openings. Forming the openings at approximately equal intervals in the circumferential direction of the movable member, that is, the opening of the openings at approximately 360 / N degrees, makes it possible for the forces applied by the reversion portions of the flat cables to be applied. uniformly to the mobile member. The inner cylindrical section of a hinge will be provided to form a bundle at one end of each of the flat cables in one place and will conduct the end of each of the flat cables that exit the second housing through the hinge. It makes it possible to simplify the structure of the connection with an external connector.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top plan view of a rotary connector in accordance with one embodiment of the present invention. Figure 2 is a sectional view of the rotary connector; Figure 3 is a schematic illustrative representation of an essential portion of the rotating connector; Figure 4 is a top plan view of a first known rotatable connector; and Figure 5 is a schematic representation of a second known rotary connector.

DESCRIPTION OF THE PREFERRED MODALITIES A mode of the present invention will be described with reference to Figures 1-3. As shown in Figures 1-3, a rotary connector according to one embodiment of the present invention includes a fixed housing 1, a mobile housing 2 rotatably connected to the fixed housing 1, the first and second flat cables 3 and 4 connected after two housings 1 and 2, and a movable member 5 which is disposed between the housings 1 and 2 so that it can rotate coaxially with the moving housing 2.

The fixed housing 1 includes an upper channel 6 and a lower case 7 which are combined in one piece, and the outer cylindrical section 8 formed on the lower case 7. The housing rnoVLl 2 includes an inner cylindrical section 9. The section The cylindrical outer 8 and the inner cylindrical section 9 are arranged coaxially, and the annular-containing space 10 is formed between the cylindrical parts 8 and 9. Arranged in the containing space LO is the mobile member 5 which includes a plate ring rotary swivel 11, a multitude of rollers 1? rotatably connected to trees extending from the turntable 11, and a pair of fixed rollers 13. A first opening 14 is formed between a fixed cylinder 13 and one of the rollers. 12, and a second opening 15 is formed between the other fixed cylinder 13 and another one of the rollers 12, the openings 14 and 15 being located at approximately 180 degrees apart. As illustrated in Figure 3, the width of the first opening 14 in the circumferential direction is denoted as Ui, and the width of the second opening 15 in the circumferential direction is denoted W2. In accordance with the present invention, these widths satisfy the Wi < W-2. The first and second planar cables 3 and 4 are each formed as a band composed of a multitude of parallel conductors made, for example, of copper formed on a surface of a base film made, for example, of an insulating tape formed of PET ™ For purposes of explanation, the first flat cable 3 is drawn in black, while the second flat cable 4 is drawn in white. The outer ends of the two flat cables 3 and 4 are connected to a fixed hinge 16 secured to the outer cylindrical section 8 and electrically driven out of the fi xing housing 1 through the fixed hinge 16. The inner ends of the two flat cables 3 and 4 are < connected to a movable joint 17 fixed to the inner cylindrical section 9 and electrically driven from the mobile housing 2 through the joint 17. Both flat cables 3 and 4 are housed in the containment space 10 so as to be wound on the counterclockwise along the inner wall of the outer cylindrical section 8 from the fixed joint 16, the first flat cable 3 being on the inner side. The first and second flat cables 3 and 4 are then separated so that a U-shaped reversing portion 3A of the first flat cable 3 passes through the first opening 14, while the U-shaped reversion portion 4A of the second flat cable 4 passes through the second opening 15. The first and second flat cables are then wound clockwise on the peripheral surface of the inner cylindrical section 9 with the first flat cable 3 on the side exterior haeta the joint 17.

Therefore, the inner end of the first flat cable 3 is wound directly around the inner cylindrical section 9 while the inner end of the second flat cable 4 is wound around the inner cylindrical section 9 through approximately one thickness of the first flat cable 3. More specifically, if the diameter of the inner cylindrical section 9 of the moving housing 2 is denoted as D and the thicknesses of the flat cables 3 and 4 are designated as t, then the winding diameter of the first flat cable 3 is D, while the winding diameter of the second flat cable 4 is (D + 2t). Therefore, the winding diameter of the second flat cable 4 wound around the inner cylindrical section 9 is larger than that of the first flat cable 3 wound around the inner cylindrical section 9. The widths Ui and U2 of the first and second openings second 14 and 15, respectively, are determined by that difference of the winding diameters taken into consideration; that is, in width Ui of the first opening 14 through which the reversing portion 3a of the first flat cable 3 having a smaller winding diameter passes, is smaller than the width U2 of the second opening 15 a through which passes the reversion portion 4a of the second flat cable 4 having a larger winding diameter. The operation of the rotary connector according to the above-described embodiment of the present invention will now be described. In this embodiment, the fi xing 1 is secured to a stator member of an address unit and an external connector, not shown on the car body, is connected to the fixed articulation 16. The mobile housing 2 is fixed to a steering wheel that forms the rotor member of the steering unit, and an external connector, not shown, is connected on the steering wheel to the movable joint 17. In operation, when the steering wheel is rotated in clockwise or counterclockwise, the torque is transmitted to the mobile housing 2, causing the mobile housing 2 to rotate clockwise or counterclockwise. For example, when the mobile housing 2 rotates counterclockwise from the neutral position of the steering wheel, the reversing portions 3a and 4a of the first and second flat cables 3 and 4 respectively move therefore in the counter-clockwise direction in a rotation amount that is smaller than that of the mobile housing 2, and a moving member 5 also moves counterclockwise in response to movement of the hands. revelation portion 3a and 4a. As a result, two flat cables 3 and 4 are wound from the inner cylindrical section 9 and wound upside down on the outer cylindrical section 8. In this case, the reversing portion 4a of the second flat cable 4 having a diameter of The larger winding moves faster than the reversing portion 3a of the first flat cable 3 has a smaller winding diameter; however, due to the relationship Ui < U2, the two reversing portions 3a and 4a push the fixed cylinders 13 which are respectively located at one end of each of the openings 14 and 15, allowing the movable member 5 to move smoothly in the containment space 10 being subject to the forces applied by the two reversal portions 3a and 4a. On the contrary, when the mobile housing 2 rotates clockwise from a state in which the steering wheel is in the neutral position the reversing portions 3a and 4a of the first and second flat cables 3 and 4 respectively, it moves accordingly in the clockwise direction in the amount of rotation that is less than that of the mobile housing 2, and the movable member 5 also moves clockwise in response to the movement of the reversion portions 3a and 4a. As a result, the flat cables 3 and 4 are unwound from the outer cylindrical section 8 and wound onto the inner cylindrical section 9. In this case, the reversion portion 4a in the second plane 4 having a further winding diameter large moves faster than the reversing portion 3a in the first flat cable 3 having a smaller winding diameter; however due to the relationship Ui < U2, the two reversing portions 3a and 4a pull the rollers 12 which are respectively located at the other ends < The openings 14 and 15 allow the movable member 5 to move smoothly therein. containment space 10 being subjected to the forces applied by the two reversing portions 3a and 4a. Thus, in the embodiment described above, the widths Ui and U2 of the first and second openings 14 and 15 through which the reversion portions 3a and 4a of the flat cables 3 and 4 respectively pass, conform to < liferent.es values according to the difference of the winding diameters of the flat cables 3 and 4 wound around the inner cylindrical section 9. Therefore, when the mobile housing 2 is rotated, the member 5 is rotationally driven mainly by the reversing portion 4a of the flat cable 4 having the largest winding diameter, however, the reversion portion 3a of the flat cable 3 comes into contact with the end of the first opening 14, so that the forces of the portions of reversion 3a and 4a of the flat cables 3 and 4 respectively, are applied to the mobile member 5 in order to move the movable member smoothly, especially because the first and second openings 14 and 15 are formed in positions opposite to 180 ° on the member 5. Further, a bundle of the inner ends of the flat cables 3 and 4 is formed in the same place by the movable joint 17, thus allowing the structure The connection to the external connector on the steering wheel is simplified. Two flat cables 3 and 4 are employed in the above-described embodiment. However, the present invention can also be applied to a case in which three or more flat cables are used. In the case of which three or more flat cables are used, the widths of a multitude of openings through which the reversion portions of the flat cables pass are properly adjusted according to the differences within the winding diameters of the cables. flat cables wound around the inner cylindrical section. In this way, the present invention provides the following advantages. Providing a movable member disposed of a containment space with a multitude of openings through which the reversion portions of a multitude of flat cables pass, and adjusting the width of one of the openings in the circumferential direction so that it is more smaller than the others, even without the reversion portions of the flat cables moving at different speeds due to the different winding diameters when the flat cables are wound or unwound, the forces of these reversion portions are applied respectively to the mobile member to In order to gently rotate the mobile member. Further, by forming the openings at approximately equal intervals in the circumferential direction of the movable member, the forces from the reversion portions of the flat cables are uniformly applied to the movable member. Furthermore, the structure of the connection of an external connector can be simplified by providing the cylindrical inner section of a joint to form a bundle of one end of each of the flat cables in the same place and knowing the ends of the flat cables outside. of the second accommodation.

Claims (16)

NOVELTY OF THE INVENTION CLAIMS

1. - A rotating connector comprising: a prirner housing having an outer cylindrical section; a second housing that is rotatably fixed to said first housing and having an inner cylindrical section opposite said outer cylindrical section so that an annular containment space is formed therebetween; a set of flat cables that are wound in said containment space, each of said set of flat cables having a first portion wound in a first direction, a second portion wound in a second direction, and a reversion portion connecting the portions first and second, wherein the opposite ends of the set of flat cables are respectively fixed to said outer cylindrical section and said inner cylindrical section; and a movable member that is movably disposed in said containment space and having a multitude of openings through which the reversion portions of said planar cables pass; wherein the width of at least one of said openings in the circumferential direction is smaller than those of the other openings.

2. A rotary connector according to claim 1, further characterized in that said openings are provided at approximately equal intervals in the circumferential direction of said mobile member.

3. A rotary connector according to claim 1, further characterized in that said inner cylindrical section is provided with a joint to form a bundle of one end of each of said flat cables in a single place.

4. A rotating connector according to claim 2, further characterized in that said inner cylindrical section is provided with a joint to form a bundle of one end of each of said flat cables in a single place.

5. A rotary connector according to claim 1, further characterized in that said outer cylindrical section is provided with a joint to form a bundle of one end of each of said flat cables in a single place.

6. A rotary connector according to claim 2, further characterized in that said outer cylindrical section is provided with a joint to form a bundle of one end of each of said flat cables in one place-.

7. A rotary connector according to claim 1, further characterized in that at least one of said set of openings is formed by a roller mounted rotatably on the movable member and a rijo cylinder mounted on the movable member.

8. A rotary connector according to claim 2, further characterized in that at least one of said multitude of openings is formed by a roller mounted rotatably on the movable member and a fi ne cylinder mounted on the movable member.

9. A rotary connector comprising:? N first housing that has an outer cylindrical section; a second housing which is fixed rotatably to said first accommodation and having an inner cylindrical section opposite said outer cylindrical section so that an annular containment space is formed between the same; two flat cables that are wound in said containment space, each of said two flat cables having a first portion wound in a first direction, a second portion wound in a second direction and a reversion portion connecting the first and second portions , wherein the opposite ends of the two flat cables are respectively fixed to said outer cylindrical section and said inner cylindrical section; and a movable member which is movably disposed in said containment space and which has two apertures through which reversal portions of the two said flat cables pass respectively; wherein the width of one of the two said openings in the circumferential direction is adjusted to be smaller than that of the other.

10. A rotating connector according to claim 9, further characterized in that said two openings are provided in separate positions at 180"C on said movable member

11. A rotary connector according to claim 9, further characterized in that said inner cylindrical section is provided with a hinge to be A bunch of one end of each of said flat cables in a single place

12. A rotating connector according to claim 10, further characterized in that said inner cylindrical section is provided with a joint to form a bunch of a

13. A rotary connector according to claim 9, further characterized in that said outer cylindrical section is provided with a hinge to form a bundle at one end of each of the said cylindrical section. said flat cables in one place

14. A rotary connector according to claim 10, further characterized by That said outer cylindrical section is provided with a hinge to form a bundle of an end of each of said flat cables in a single place.

15. A rotary connector according to claim 9, further characterized in that at least one of said two openings is formed by a roller mounted rotatably on the movable member and a fixed cylinder mounted on the movable member.

16. A rotary connector according to claim 10, further characterized in that at least one of said said openings is formed by a roller mounted rotatably on the movable member and a fixed cylinder mounted on the movable member.