Rotary connector having slip ring mechanism

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electrical connectors for automotive vehicles. In particular, the present invention relates to a rotary connector that connects a steering wheel of a vehicle and a vehicle body electrically.

2. Description of the Related Art

One such prior art rotary connector is described in, for example, Japanese Patent Publication No. 355955. This rotary connector has a housing body that includes a rotor housing and a stator housing. The housing body houses a spiraled flat cable that makes electrical connection between a vehicle body and a steering wheel. The housing body houses a spiraled flat cable that makes electrical connection between a vehicle body and a steering wheel. Such a connector is used for an air bag system or an alarm system that is provided to a steering wheel. Because the flat cable carries small currents, the flat cable is of the construction in which thin wires are covered with a film material. The flat cable of the prior art rotary connector functions sufficiently for carrying small currents.

Recently, some steering wheels have a heater, which requires a large current. If the aforementioned flat cable is used for supplying a current to a handle heater, there is a possibility that the wires of the flat cable generate too much heat and melt the film material covering the wires. Therefore, the wires of the flat cable are not capable of carrying a large current, and the flat cable is unsuitable for a handle heater.

In view of this problem, the applicant of the present invention has proposed a structure disclosed in Japanese Patent Laid-Open No. 2001-196145. This structure includes a flat cable and an additional cord for carrying a large current for a handle heater. This structure uses a flat cable for supplying small currents to, for example, an air bag and an alarm, and a large-current cord for supplying a large current to the handle heater.

However, the aforementioned large-current cord runs through a shaft sleeve inserted into a steering shaft and is connected to a power supply through a slip ring mechanism outside of the stationary stator housing. To accommodate the large-current cord and slip ring mechanism, a special space is required in the shaft sleeve and outside of the stator housing. Thus, the overall height of the apparatus increases by the height of the slip ring mechanism, making the apparatus large in size.

In addition, because the cord runs in the shaft sleeve, there is a possibility that the cord contacts a steering shaft to rub the steering wheel. Also, since the slip ring mechanism is provided outside of the stator housing, the sounds created by the slip ring mechanism may leak to the outside and cause abnormal sounds.

In rotary connectors used for automobiles, a large number of switches are arranged in the pads and spoke of the steering wheel, and a large number of wires are required for making electrical connection between the switches and the vehicle body. However, because various devices are mounted around the steering wheel, the axial height of the flat cable having wires therein and the height of a rotary connector have to be designed to a specific value. This limits the number of wires that can be included in the flat cable, e.g., several wires.

Some rotary connectors have a plurality of flat cables in order to solve this problem. However, the number of flat cables is limited only to two or three due to a limited space for mounting terminals to which the opposed ends of the flat cables are fixed.

SUMMARY OF THE INVENTION

A first object of the present invention is to provide a rotary connector that allows increasing the number of electrical paths that connect the vehicle body and the steering wheel while still maintaining the overall size as small as possible.

A second object of the invention is to provide a rotary connector that has a large-current path in addition to the flat cable while still maintaining the overall size of the rotary connector as small as possible.

A third object is to provide a rotary connector that prevents occurrence of abnormal sounds.

To accomplish these and other objects of the invention, a rotary connector is provided having a stationary member supported on a body side of an automobile; a rotative member rotatably supported on the stationary member, the rotative member being rotatable together with a steering wheel; a floating spacer disposed between the stationary member and the rotative member and having a gap that extends in a radial direction of the floating spacer so that an inner space of the floating spacer communicates with an outer space of the floating spacer through the gap, the floating spacer being pivotal when the rotative member rotates; and a flat cable having one end that is supported on the stationary member and connected to a power supply side, the other end that is supported on the rotative member and connected to an electrical apparatus on the steering wheel side, and a mid folding portion that passes through the gap in a floating spacer to fold back so that the flat cable is wound around the outer surface and the inner surface of the floating spacer, the flat cable lying between the stationary member and the rotative member.

The rotary connector has a slip ring mechanism, comprising: a stationary contact provided on the stationary member, the stationary contact being connected to the power supply and opposing the floating spacer so that the stationary contact extends along a pivotal path of the floating spacer; a movable contact provided on the rotative member, the movable contact being connected to an electrical apparatus on the steering wheel side and opposing the floating spacer so that the movable contact extends along a pivotal path of the floating spacer; and a floating contact provided to the floating spacer which is electrically connected to the stationary contact and the movable contact.

According to another aspect of the present invention, the rotary connector further comprises an annular stationary contact provided on the stationary member, the annular stationary contact being connected to the power supply and opposing the floating spacer to extend along the pivotal path of the floating spacer; an annular movable contact provided on the rotative member, the annular movable contact being connected to the electrical apparatus on the steering wheel side and opposing the floating spacer to extend along the pivotal path of the floating spacer; and a floating contact provided to the floating spacer which is in resilient contact with the stationary contact and the movable contact.

According to another aspect of the present invention, the rotary connector further comprises a contact-receiving recess formed in the floating spacer and receiving the floating contact therein and exposing two opposed ends of the floating contact to the stationary contact and the movable contact. The floating contact is received in the contact receiving recess.

According to yet another aspect of the present invention, the floating contact has contacts on its opposed two ends thereof and an electrically conductive spring that makes the contacts electrically continuous with each other and makes the floating contact in resilient contact with the stationary contact and the movable contact.

Numerous other objects of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described an embodiment of the present invention, simply by way of illustration of one of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more clearly appreciated as the disclosure of the invention is made with reference to the accompanying drawings. In the drawings:

FIG. 1

is a perspective view of a rotary connector according to a first embodiment of the invention.

FIG. 2

is a top view of the rotary connector according to the first embodiment.

FIG. 3

is an exploded perspective view of the rotary connector according to the first embodiment.

FIG. 4

is a cross-sectional view of the first embodiment taken along line SA—SA of FIG.

2

.

FIG. 5

is a cross-sectional view of a second embodiment taken along the same line of FIG.

4

.

FIG. 6

is a top view of the interior of a rotary connector according to a third embodiment.

FIG. 7

is a cross-sectional view of the third embodiment taken along line SB—SB of FIG.

6

.

FIG. 8

is a side view of a rotary connector according to the third embodiment.

FIG. 9

is a top view illustrating grooves formed in a bottom housing according to the third embodiment.

FIG. 10

is an exploded perspective view of a rotary connector according to a fourth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1

is a perspective view and

FIG. 2

is a top view of a rotary connector

1

according to a first embodiment of the present invention. The rotary connector

1

in

FIGS. 1 and 2

is used to make electrical connection between various apparatuses provided on a steering wheel side of an automobile and a power supply on the vehicle side.

The rotary connector

1

includes a stationary housing

3

that serves as a stationary member, and a rotative housing

5

that serves as a rotative member. The stationary housing

3

is formed of, for example, a resin material and is fixedly mounted to the body of an automobile. According to the present embodiment, the base of a combination switch is fixed to a steering column on the body of an automobile. The stationary housing

3

includes a side housing

6

having a cylindrical wall

7

formed in one piece with flanges

9

. Each flange

9

has a mounting hole

11

formed therethrough so that the side housing

6

can be fastened via the mounting hole

11

. Thus, the stationary housing

3

is positioned relative to the combination switch with the mounting flanges

9

aligned with the base of the combination switch. Bolts are inserted into the mounting holes

11

and then screwed into nuts, thereby fastening the stationary housing

3

.

The stationary housing

3

has a frame

12

on one side of the wall

7

and a small-current connector

13

is provided under the frame

12

. The frame

12

has an upper opening capped with a lid

17

which is detachably fitted to the upper opening of the frame

12

. The housing

3

also has a large-current connector

15

provided near the small-current connector

13

.

The rotative housing

5

is rotatably supported on the stationary housing

3

and is rotatable together with the steering wheel. The rotative housing

5

is formed of a resin material substantially into a doughnut-shape. The rotative housing

5

has a cylindrical outer geometry configured to the cylindrical side wall

7

of the stationary housing

3

, the cylindrical outer geometry being substantially the same size as the cylindrical side wall

7

. The rotative housing

5

has a shaft sleeve

19

formed in the middle thereof. The rotative housing

5

has a rotative holder

77

assembled integrally with the rotative housing

5

. Alternatively, the rotative housing

5

and the rotative holder

77

may be made in one piece construction.

The stationary housing

3

and the rotative housing

5

are coupled through an attachment

21

in such a way that the housings

3

and

5

are rotatable relative to each other. The rotative housing

5

is formed with a pair of rectangular through-holes

23

a

and

23

b

through which later-described terminals

25

a

and

25

b

of the flat cables extend.

A large-current connector

27

is provided on the upper surface of a rotative housing

5

, and large-current terminals

29

a

and

29

b

project upward from the connector

27

. The large-current terminals

29

a

and

29

b

are connected to a connector of an electrical apparatus provided on the steering wheel side. One such electrical apparatus is a handle heater that heats the steering wheel to provide a warm grip for the operator.

The rotary connector

1

will be further described with reference to

FIGS. 3 and 4

.

FIG. 3

is an exploded perspective view of the rotary connector

1

.

FIG. 4

is a cross-sectional view taken along line SA—SA of FIG.

2

.

As shown in

FIGS. 3 and 4

, the cylindrical wall

7

of the side housing

6

of the stationary housing

3

has an upper edge portion

31

formed in the shape of a step. The side wall

7

is formed with engagement holes

33

aligned in a circumferential direction at equal intervals.

The small-current connector

13

has a terminal support

37

in the frame

12

and a hood

45

below the frame

12

. The terminal support

37

has a pair of recesses

39

a

and

39

b

for accommodating the terminals. There are provided slits

41

beside the recesses

39

a

and

39

b

, respectively. The side wall

7

is formed with a slit

43

through which the space inside of the side wall

7

communicates with the space inside of the frame

12

.

The stationary housing

3

has a bottom housing

47

that is coupled to the side housing

6

. The stationary housing

3

may be of the construction in which the side housing

6

and the bottom housing

47

are formed in one piece. The bottom housing

47

is molded from a resin material into the shape of a doughnut. The outer diameter of the bottom housing

47

is much the same as the inner diameter of the side wall

7

of the side housing

6

, so that the bottom housing

47

can be fitted into the side wall

7

of the side housing

6

. A center hole

53

formed in the bottom housing

47

has a bearing portion

55

that projects axially and serves as a bearing for the rotative housing

5

.

The bottom housing

47

has a plurality of engagement lugs

51

that project from an outer circumferential surface

49

of the bottom housing

47

. These engagement lugs

51

are formed corresponding to engagement holes

33

formed in the side wall

7

of the side housing

6

, so that when the engagement lugs

51

engage the engagement holes

33

, the bottom housing

47

is assembled to the side housing

6

.

There are provided a pair of annular stationary contacts

57

a

and

57

b

on the upper surface of the bottom housing

47

. The stationary contacts

57

a

and

57

b

are insert molded with the bottom housing

47

molded from a resin material, and the upper surface of the stationary contacts

57

a

and

57

b

are substantially flush with the upper surface of the bottom housing

47

. The upper surface of the bottom housing

47

in which the annular stationary contacts

57

a

and

57

b

are formed opposes floating spacers which will be described later.

Along the locus of pivotal movement of the floating spacers, the stationary contacts

57

a

and

57

b

are formed in an annular shape. The stationary contacts

57

a

and

57

b

are connected to the power supply side, and terminals

59

a

and

59

b

extend from portions of the stationary contacts

57

a

and

57

b

, respectively. The terminals

59

a

and

59

b

are exposed in the large-current connector

15

that is formed in one piece with the bottom housing

47

.

Thus, in the present embodiment, the stationary contacts

57

a

and

57

b

are provided on the stationary housing

3

side. The stationary contacts

57

a

and

57

b

are connected to the power supply and oppose the floating spacers to form an annular shape along the pivotal path of movement of the floating spacers.

The attachment

21

is formed of a resin material and couples the stationary housing

3

to the rotative housing

5

as described. The attachment

21

has four resilient tongues

61

and four abutting straps

63

between the tongues

61

. The tongues

61

and abutting straps

63

are alternate each other in a circumferential direction. Each resilient tongue

61

has a fitting window

65

formed therein.

The rotative housing

5

has coupling lugs

67

and abutting straps

69

formed on the inner circumferential surface of the shaft sleeve

19

. The coupling lugs

67

are formed at four locations in a circumferential direction, corresponding to the fitting windows

65

. The abutting straps

69

are formed at four locations in a circumferential direction, corresponding to the abutting strap

63

.

There are provided a pair of annular movable contacts

71

a

and

71

b

on the underside of the rotative housing

5

. The movable contacts

71

a

and

71

b

are insert-molded with the rotative housing

5

formed of a resin material. The surfaces of the movable contacts

71

a

and

71

b

are flush with the underside of the rotative housing

5

. The inner movable contact

71

a

has the same diameter and width as the stationary contact

57

a

, and the outer movable contact

71

b

has the same diameter and width as the stationary contact

57

b

. The underside of the rotative housing

5

on which the annular movable contacts

71

a

and

71

b

are formed opposing the floating spacers will be described later.

Formed along the locus of the pivotal motion of the floating spacers are the movable contacts

71

a

and

71

b

. The movable contacts

71

a

and

71

b

are connected to electrical apparatuses on the steering wheel side. Portions of the movable contacts

71

a

and

71

b

extend just as the terminals

59

a

and

59

b

of the stationary contacts

57

a

and

57

b

, so that the portions of the movable contacts

71

a

and

71

b

are electrically connected to the terminals

29

a

and

29

b

of the large-current connector

27

. As mentioned above, one such electrical apparatus is a handle heater that heats the steering wheel.

Thus, in the present embodiment, the annular movable contacts

71

a

and

71

b

are provided on the rotative housing

5

side. The annular movable contacts

71

a

and

71

b

are connected to the electrical apparatuses on the steering wheel side as well as opposing the floating spacers to describe a ring shape along the locus of pivotal movement of the floating spacers. The slip ring mechanism is formed of the stationary contacts

57

a

and

57

b

and the movable contacts

71

a

and

71

b

. The flat springs

93

and

95

may also be applied to electrical apparatuses that consume small currents.

As shown in

FIG. 4

, the rotative housing

5

has a circumferential flange

73

on its outermost edge. The circumferential flange

73

fits over the upper end portion

31

of the stationary housing

3

. The rotative housing

5

also has a shaft engagement step

75

formed in a lower end portion of a circumferential surface of the shaft sleeve

19

. The shaft engagement step

75

fits to the bearing portion

55

of the bottom housing

47

.

The rotative holder

77

is disposed between the stationary housing

3

and the rotative housing

5

. The rotative holder

77

is formed of, for example, a resin material in the shape of a ring, and can rotate together with the steering wheel. The inner diameter of the rotative holder

77

is slightly larger than the outer diameter of the shaft sleeve

19

of the rotative housing

5

. The rotative holder

77

fits over the shaft sleeve

19

in such a way that the rotative holder

77

is rotatable relative to the shaft sleeve

19

. The rotative holder

77

has terminal fitting portions

79

a

and

79

b

. The terminal fitting portions

79

a

and

79

b

have slits

81

a

and

81

b

formed therein, respectively.

The rotative holder

77

may be formed in one piece with the rotative housing

5

in such a way that the rotative holder

77

depends from an inner ceiling of the rotative housing

5

. The rotative holder

77

may be formed in one piece with the shaft sleeve

19

of the rotative housing

5

. If the rotative holder

77

and rotative housing

5

are formed in one piece, terminals

109

a

and

109

b

of the first and second flat cables

103

a

and

103

b

fit into the through-holes

23

a

and

23

b

from the underside. The terminal fitting portions

79

a

and

79

b

of the rotative holder

77

may also serve as the through-holes

23

a

and

23

b

of the rotative housing

5

or may be communicated with the through-holes

23

a

and

23

b

. The ring-shaped rotative holder

77

is required only to fix the terminals

109

a

and

109

b

to the rotative housing

5

, i.e., the rotative holder

77

may have a shape such as a box or a connector, or may have any other shapes.

There are provided floating spacers

83

a

and

83

b

between the stationary housing

3

and rotative housing

5

. The floating spacers

83

a

and

83

b

surround the rotative holder

77

. The floating spacers

83

a

and

83

b

are molded from, for example, a resin material. The floating spacers

83

a

and

83

b

are disposed in a mating manner to make a ring shape. The floating spacers

83

a

and

83

b

each have a convex end and a concave end so that the convex ends of the floating spacers

83

a

and

83

b

face the concave ends of the floating spacers

83

a

and

83

b

to define gaps

85

a

and

85

b

. Thus, the stationary housing

3

on the outside of the floating spacers

83

a

and

83

b

can communicate with the rotative holder

77

on the inside of the floating spacers

83

a

and

83

b

through the gaps

85

a

and

85

b

. The gaps

85

a

and

85

b

are in the shape of a curved slit.

A plate-like member is provided to the bottoms of the floating spacers

83

a

and

83

b

so that upper ends of the gaps

85

a

and

85

b

are open. The floating spacer

83

a

and floating spacer

83

b

are joined integrally at the bottom portions of the gaps

85

a

and

85

b

. Alternatively, the floating spacers

83

a

and

83

b

may be separated from each other at the gaps

85

a

and

85

b

. Still alternatively, a plurality of projections may be formed on upper inner surfaces of the floating spacers

83

a

and

83

b

, and a stepped portion may be formed in an upper outer circumferential surface of the rotative holder

77

. Then, the floating spacers

83

a

and

83

b

may be assembled to the rotative holder

77

in such a way that the plurality of projections engage the stepped portion to allow the floating spacers

83

a

and

83

b

to hang from and slide on the stepped portion.

The floating spacers

83

a

and

83

b

have a pair of floating contacts

87

a

and

87

b

. The floating contact

87

a

resiliently contacts the stationary contact

57

a

and movable contact

71

a

, while the floating contact

87

b

resiliently contacts the stationary contact

57

b

and movable contact

71

b.

The movable contacts

87

a

have bullet-shaped contacts

89

a

and

89

b

. The movable contacts

87

b

have bullet-shaped contacts

91

a

and

91

b

. The contacts

89

a

and

89

b

are coupled together through an electrically conductive flat spring

93

, while the contacts

91

a

and

91

b

are coupled together through an electrically conductive flat spring

95

. Thus, the contacts

89

a

and

89

b

are electrically continuous to each other through the flat spring

93

, and the contacts

91

a

and

91

b

are electrically continuous to each other through the flat spring

95

.

The resilient force of the flat spring

93

causes the contacts

89

a

and

89

b

to resiliently contact with the stationary contact

57

a

and movable contact

71

a

, respectively. The resilient force of the flat spring

95

causes the contacts

91

a

and

91

b

to resiliently contact with the stationary contact

57

b

and movable contact

71

b

, respectively. Instead of forming the contacts

89

a

,

89

b

,

91

a

, and

91

b

, the flat springs

93

and

95

may be bent at their end portions so that the flat spring

93

directly contacts the stationary contacts

57

a

and movable contact

71

a

, and the flat spring

95

directly contacts the stationary contact

57

b

and movable contact

71

b.

The movable contacts

87

a

and

87

b

are supported by the contact receiving recesses

97

a

and

97

b

provided on the floating spacers

83

a

and

83

b

, respectively. The contact receiving recesses

97

a

and

97

b

include spring receiving portions

99

a

and contact receiving portions

99

b

, respectively, which are configured to the shapes of the movable contacts

87

a

and

87

b

, respectively. These contact receiving recesses

97

a

and

97

b

are not arranged in the same orientation, i.e., the recess

97

a

has the contact receiving portion

99

b

close to the inner circumferential surface of the floating spacer

83

a

, and the recess

97

b

has the contact receiving portion

99

b

close to the outer circumferential surface of the floating spacer

83

b.

With the movable contacts

87

a

and

87

b

accommodated in the contact receiving recesses

97

a

and

97

b

, the contacts

89

a

and

89

b

on the opposite ends of the floating contact

87

a

project from the contact receiving portion

99

a

to resiliently contact the stationary contact

57

a

and movable contact

71

a

, and the contacts

91

a

and

91

b

on the opposite ends of the floating contact

87

b

project from the contact receiving portion

99

b

to resiliently contact the stationary contact

57

b

and movable contact

71

b

. In this manner, the contacts

57

a

and

57

b

, movable contacts

71

a

and

71

b

, and floating contacts

87

a

and

87

b

form a so-called slip ring mechanism in a space defined between the stationary housing

3

and rotative housing

5

.

A set

101

of wound flat cables is provided in a space defined between the stationary housing

3

and the rotative holder

77

. The set

101

of flat cables according to the embodiment includes two cables: a first flat cable

103

a

and a second flat cable

103

b

. The first flat cable

103

a

and second flat cable

103

b

include fixed-end terminals

107

a

and

107

b

at one end of flat portions

105

a

and

105

b

, and rotating-end terminals

109

a

and

109

b

at their other end of flat portions

105

a

and

105

b

, respectively. The fixed-end terminals

107

a

and

107

b

are connected to the power supply and have terminals

111

a

and

111

b

, respectively.

The rotating-end terminals

109

a

and

109

b

are connected to the electrical apparatuses on the steering wheel side, and have terminals

25

a

and

25

b

, respectively. The electrical apparatuses in the embodiment include, for example, an air bag apparatus or an alarm provided to the steering wheel, a shift down switch and a shift-up switch for an automatic transmission, an ASCD (auto speed control device) switch, and an audio switch.

The flat portions

105

a

and

105

b

include a plurality of belt-shaped electrically conductive wires sandwiched between two sheets of resin films made of an insulating resin, the conductive wires being spaced apart by a predetermined distance. The resin films are heated under pressure, thereby forming a flat cable integrally.

The terminals

111

a

,

111

b

,

25

a

, and

25

b

are insert-molded from a resin material with the terminal

107

a

,

107

b

,

109

a

, and

109

b

. The terminals

111

a

,

111

b

,

25

a

, and

25

b

are connected to the conductive wires on the flat portions

105

a

and

105

b.

The first flat cable

103

a

is wound as follows: Starting from the fixed-end terminal

107

a

, the first flat cable

103

a

makes a round through the outermost circumference, then passes by an inner side of the other fixed-end terminal

107

b

to reach a mid folding portion

113

a

. Then, the first flat cable

103

a

folds back to be wound counterclockwise at the mid folding portion

113

a

, and then makes about a round and half run through the inner circumference, reaching the other rotating-end terminal

109

b.

Starting from the fixed-end terminal

107

b

, the second flat cable

103

b

makes about ¾ of one complete run clockwise through the outermost circumference, reaching a mid folding portion

113

b

where the second flat cable

103

b

folds back. Then, the second flat cable

103

b

makes about a round and a half counterclockwise, finally reaching the rotating-end terminal

109

a.

The fixed-end terminals

107

a

and

107

b

on the first and second flat cables

103

a

and

103

b

are accommodated in terminal receiving recesses

39

a

and

39

b

of the stationary housing

3

, and the terminals

111

a

and

111

b

project into the hood

45

of the small-current connector

13

.

With the fixed-end terminals

107

a

and

107

b

accommodated in the terminal receiving recesses

39

a

and

39

b

, respectively, the flat portions

105

a

and

105

b

of the flat cables

103

a

and

103

b

are inserted into the slits

41

and

43

, respectively, through a space between the side housing

6

and the floating spacers

83

a

and

83

b

. The flat portions

105

a

and

105

b

then pass along the inner circumferential surface of the side wall

7

of the stationary housing

3

, and then through the frame

12

to reach the terminal receiving recesses

39

a

and

39

b.

The other rotating-end terminals

109

a

and

109

b

of the flat cables

103

a

and

103

b

fit to the terminal fitting portions

79

a

and

79

b

of the rotative holder

77

, respectively, and the terminals

25

a

and

25

b

project from the rotative housing

5

through the through-holes

23

a

and

23

b

, respectively. The flat portions

105

a

and

105

b

of the first and second flat cables

103

a

and

103

b

pass through a space between the rotative housing

5

and the floating spacers

83

a

and

83

b

to reach the terminal fitting portions

79

a

and

79

b

through the slits

81

a

and

81

b.

In this manner, one cable of the set

101

of flat cables is folded at the mid folding portion

113

a

and inserted into the gap

85

a

defined between the floating spacers

83

a

and

83

b

, and the other cable of the set

101

of flat cables is folded at the mid folding portion

113

b

and inserted into the other gap

85

b

, so that the set

101

of flat cables is wound along the inner circumferential surfaces and the outer circumferential surfaces of the floating spacers

83

a

and

83

b

in a space defined between the stationary housing

3

and the rotative housing

5

.

With the above-described structure, the side housing

6

and the bottom housing

47

of the stationary housing

3

are coupled when the engagement hole

33

engages the lugs

51

. In the stationary housing

3

, the rotative holder

77

, floating spacers

83

a

and

83

b

, and set

101

of flat cables are combined as described above. The fixed-end terminals

107

a

and

107

b

of the set

101

of flat cables are accommodated in the terminal receiving recesses

39

a

and

39

b

, respectively, and the rotating-end terminals

109

a

and

109

b

are accommodated in the terminal fitting portions

79

a

and

79

b

of the rotative holder

77

.

The contact receiving recesses

97

a

and

97

b

receive the floating contacts

87

a

and

87

b

, and the rotative housing

5

fits over the contact receiving recesses

97

a

and

97

b

and the floating contacts

87

a

and

87

b

. With this condition, the terminals

25

a

and

25

b

on the inner circumferential surface of the set

101

of the flat cables project outwardly from the through-holes

23

a

and

23

b

formed in the rotative housing

5

, respectively.

The attachment

21

is inserted into the bottom housing

47

through the inner hole

53

, so that the resilient tongues

61

deform to cause the coupling lugs

67

to engage the fitting windows

65

formed in the resilient tongues

61

. With this condition, the abutting straps

63

of the attachment

21

abut the abutting straps

69

of the rotative housing

5

, thereby positioning the attachment

21

relative to the rotative housing

5

.

Grease is applied on the flange surface

21

a

of the attachment

21

so as to reduce sliding resistance between the attachment

21

and the bottom housing

47

. The flange surface

21

a

of the attachment

21

may be formed with a circumferential groove therein for holding grease.

With this assembling condition, the floating contacts

87

a

and

87

b

are pushed into the contact receiving recesses

97

a

and

97

b

, respectively, so that the flat springs

93

and

95

are caused to flex to exhibit resilient forces. As a result, the contact

89

a

of the floating contact

87

a

resiliently contacts the stationary contact

57

a

on the stationary housing

3

, while the contact

89

b

of the floating contact

87

a

resiliently contacts the movable contact

71

a

on the rotative housing

5

. Likewise, the contact

91

a

resiliently contacts the stationary contact

57

b

on the stationary housing

3

, while the contact

91

b

resiliently contacts the movable contact

71

b

on the rotative housing

5

.

With the rotary connector

1

assembled as described above, the stationary housing

3

is fastened to the base of the combination switch as mentioned previously, and the large-current connector

27

on the rotative housing

5

side fits to the steering wheel side, so that the terminals

29

a

and

29

b

of the connector

27

are connected to the electrical apparatuses on the steering wheel side. When the large-current connector

27

has fitted to the steering wheel side, the rotative housing

5

can rotate together with the steering wheel.

The terminals

25

a

and

25

b

for carrying small currents are connected to a small-current connector

13

on the steering wheel side. The small-current connector

13

is coupled to a small-current connector on the power supply side, and the large-current connector

15

is coupled to a large-current connector on the power supply side.

With this condition, operating the steering wheel causes the rotative housing

5

, rotative holder

77

, and attachment

21

to rotate together with the steering wheel. This rotation also causes the rotating-end terminals

109

a

and

109

b

on the inner ends of the flat cables

103

a

and

103

b

to move together pivotally with the rotative holder

77

. This pivotal movement causes the mid folding portions

113

a

and

113

b

of the flat cables

103

a

and

103

b

to move, so that the floating spacers

83

a

and

83

b

pivotally rotate together with the mid folding portions

113

a

and

113

b

relative to the stationary housing

3

.

Therefore, electric power can be supplied to the steering wheel side by means of the set

101

of flat cables, allowing energizing the air bag apparatus or the alarm provided to the steering wheel, the shift-down switch and shift-up switch of the automatic transmission, the ASCD (auto speed control device) switch, and the audio switch, independently of the operation of the steering wheel. At the same time as the floating pivotal movement of the floating spacers

83

a

and

83

b

, the floating contacts

87

a

and

87

b

also perform floating pivotal movement. Because the stationary contacts

57

a

and

57

b

and the movable contacts

71

a

and

71

b

have an annular shape that runs along the locus of pivotal movement of the floating spacers

83

a

and

83

b

, the resilient force of the flat spring

93

causes the contacts

89

a

and

89

b

of the floating contact

87

a

to be in contact with the stationary contact

57

a

and movable contact

71

a

at all times. Likewise, the resilient force of the flat spring

95

causes the contacts

91

a

and

91

b

of the floating contact

87

b

to be in contact with the stationary contact

57

b

and movable contact

71

b

at all times.

Therefore, electric power can be supplied from the power supply side to the steering wheel side independently of the operation of the steering wheel, the electric power being supplied from the large-current connector

15

to the large-current connector

27

through the stationary contacts

57

a

and

57

b

, floating contacts

87

a

and

87

b

, and movable contacts

71

a

and

71

b

. In this manner, a large current can be supplied to, for example, the handle heater independently of the operation of the steering wheel. Therefore, this structure prevents large current from flowing through the set

101

of flat cable, thereby protecting the flat cable.

Because the floating contacts

87

a

and

87

b

are provided on the floating spacers

83

a

and

83

b

, space can be utilized efficiently to form a slip ring mechanism having the stationary contacts

57

a

and

57

b

, movable contacts

71

a

and

71

b

, and floating contacts

87

a

and

87

b

without making the overall size of the rotary connector larger. In addition, the slip ring mechanism that includes the stationary contacts

57

a

and

57

b

, movable contacts

71

a

and

71

b

, and floating contacts

87

a

and

87

b

can be accommodated in a closed space defined between the stationary housing

3

and the rotative housing

5

. Thus, this structure prevents leakage of sounds created by sliding motion between the stationary contacts

57

a

and

57

b

, movable contacts

71

a

and

71

b

, and floating contacts

87

a

and

87

b

, thereby reducing abnormal sounds greatly.

In addition, the structure ensures that the contact receiving recesses

97

a

and

97

b

receive the floating contacts

87

a

and

87

b

, and the two opposed ends of the floating contacts

87

a

and

87

b

resiliently contact the stationary contacts

57

a

and

57

b

and movable contacts

71

a

and

71

b

, respectively. Thus, electric power can be reliably supplied to the electrical apparatuses on the steering wheel side.

The structure ensures that the spring force of the flat spring

93

causes the contacts

89

a

and

89

b

of the floating contact

87

a

to resiliently contact the stationary contacts

57

a

and movable contact

71

a

, and the contacts

89

a

and

89

b

can be electrically continuous through the flat spring

93

. The structure also ensures that the spring force of the flat spring

95

causes the contacts

91

a

and

91

b

of the floating contacts

87

b

to resiliently contact the stationary contacts

57

b

and movable contact

71

b

, and the contacts

91

a

and

91

b

can be electrically continuous through the flat spring

95

. Thus, without increasing the size of the rotary connector, electric power can be supplied from the power supply side to the electrical apparatuses on the steering wheel side through the stationary contacts

57

a

and

57

b

, floating contacts

87

a

and

87

b

, and movable contacts

71

a

and

71

b

, independently of the operation of the steering wheel.

In the aforementioned embodiment, the flat springs

93

and

95

cause the contacts

89

a

,

89

b

,

91

a

, and

91

b

to resiliently contact the floating contacts

87

a

and

87

b

to the stationary contacts

57

a

and

57

b

and the movable contacts

71

a

and

71

b

, respectively. Alternatively, the construction shown in

FIG. 5

may be possible.

FIG. 5

is a cross-sectional view corresponding to FIG.

4

. According to the construction in

FIG. 5

, the floating contacts

115

a

and

115

b

employ the electrically conductive coil springs

117

and

119

in place of the flat springs

93

and

95

for the floating contacts

87

a

and

87

b

, respectively.

Contact receiving recesses

121

a

and

121

b

that receive the floating contacts

115

a

and

115

b

are in the form of a through-hole. The coil spring

117

may be in one piece with the contacts

89

a

and

89

b

or assembled between the contacts

89

a

and

89

b

. The coil spring

119

and the contacts

91

a

and

91

b

may be formed in a manner similar to the coil spring

117

. The other configuration of the rotary connector

1

shown in

FIG. 5

is the same as the aforementioned embodiment shown in

FIGS. 1

to

4

.

Thus, in the embodiment in

FIG. 5

, the repulsive force of the coil spring

117

for the floating contact

115

a

causes the contacts

89

a

and

89

b

to resiliently contact the stationary contact

57

a

and movable contact

71

a

. With the floating contact

115

b

, the repulsive force of the coil spring

119

causes the contacts

91

a

and

91

b

to resiliently contact the stationary contact

57

b

and movable contact

71

b

, while also making electrical continuity between the contacts

89

a

and

89

b

by means of the coil spring

117

, and between the contacts

91

a

and

91

b

by means of the coil spring

119

.

Thus, the present embodiment also provides much the same advantages as the previously mentioned embodiment. In the present embodiment, the contact receiving recesses

121

a

and

121

b

may be in the shape of a through-hole, which will facilitate manufacture of the floating spacers

83

a

and

83

b

. Because the floating contacts

115

a

and

115

b

do not have a particular orientation, the floating contacts

115

a

and

115

b

may be assembled into the contact receiving recesses

121

a

and

121

b

without difficulty.

The rotary connector

1

may be in the form in which the aforementioned rotative member and the stationary member are interchanged. In other words, the stationary housing

3

may be mounted under the steering wheel so that the housing

3

actually functions as a rotary member, and the rotative housing

5

may be fixed to the base of the combination switch so that the housing

5

actually functions as a stationary member. This interchanged structure also allows electrical connection between the apparatuses on the steering wheel side and the apparatuses on the vehicle body side as in the rotary connector

1

.

If the slip ring device is used to supply current to a single electrical circuit, then the following configuration can be employed. That is, the floating spacers

83

a

and

83

b

may be an electrically conductive body in the shape of a doughnut. A contact in the form of a contact spring is disposed on the underside of the rotative housing

5

and slides on the upper surface of the floating spacers

83

a

and

83

b

. A contact in the form of a contact spring, which slides on the underside of the floating spacers

83

a

and

83

b

, is disposed on the upper surface of the bottom housing

47

of the stationary housing

3

. These two contacts are then electrically connected through the electrically conductive floating spacers

83

a

and

83

b

. The apparatuses are grounded via the steering wheel.

The rotary connector

1

may be in the form of a slip ring device having the following configuration. The floating spacers

83

a

and

83

b

are arranged to form the shape of a doughnut as shown in FIG.

10

. An annular-shaped insulating plate

300

is placed on the floating spacers

83

a

and

83

b

to cover the gaps

85

a

and

85

b

, and another annular insulating plate

301

is placed under the floating spacers

83

a

and

83

b

to cover the gaps

85

a

and

85

b

. Annular floating contacts

300

a

and

300

b

are provided on the upper insulating plate

300

, and floating contacts

301

a

and

301

b

are disposed on the underside of a lower insulating plate

301

. Movable contacts

302

a

and

302

b

are disposed on the underside of a rotative housing

302

to contact the floating contacts

300

a

and

300

b

. Stationary contacts

303

a

and

303

b

are disposed on the upper surface of a bottom housing

303

of the stationary housing

3

to contact the floating contacts

301

a

and

301

b.

The outer floating contact

300

a

formed on the upper insulating plate

300

and the outer floating contact

301

a

formed on the underside of the lower insulating plate

301

are electrically connected through the terminals

301

d

that extend through the floating spacers

83

a

and

83

b

. Likewise, the inner floating contact

300

b

formed on the upper insulating plate

300

and the inner floating contact

301

b

formed on the underside of the lower insulating plate

301

are electrically connected through the terminals

301

c

that extend through the floating spacers

83

a

and

83

b.

The movable contacts

302

a

and

302

b

are resilient contacts, for example, in the form of a plurality of flat springs and are disposed in a circumferential direction at equal intervals on a rotative housing

302

. The movable contacts

302

a

and

302

b

provided on the rotative housing

302

resiliently urge the surface of the upper insulating plate

300

so that an even urging force prevents the rotative housing

302

from tilting. The plurality of outer movable contacts

302

a

arranged on the rotative housing

302

are on the same circle and are electrically continuous through a terminal

302

e

, which in turn is electrically continuous to a terminal

302

c

. A plurality of inner movable contacts

302

b

arranged on the rotative housing

302

are on the same circle and are electrically continuous through a terminal

302

f

, which in turn is continuous to the terminal

302

d.

The rotative housing

302

has couplers

302

h

and

302

i

formed on locations closer to the center of the rotative housing

302

than a terminal

302

f

. The couplers

302

h

and

302

i

receive terminals

109

a

and

109

b

of the set

101

of flat cables. The couplers

302

h

and

302

i

are formed adjacent to the shaft sleeve

302

g

or continuous to the shaft sleeve

302

g.

The stationary contacts

303

a

and

303

b

are resilient contacts in the form of a plurality of flat springs and are arranged at equal intervals on a stationary housing

303

in a circumferential direction. The stationary contacts

303

a

and

303

b

provided on the stationary housing

303

resiliently urge the surface of the lower insulating plate

301

so that an even urging force prevents the stationary housing

303

from tilting. The plurality of outer stationary contacts

303

a

arranged on the stationary housing

303

are on the same circle and are electrically continuous through the terminal

303

e

, which in turn is electrically continuous to the terminal

303

c.

The plurality of inner stationary contacts

303

b

arranged on the stationary housing

303

are on the same circle and are electrically continuous through a terminal

303

f

, which in turn is electrically continuous to a terminal

303

d.

FIGS. 6

to

9

illustrate a rotary connector

201

according to another embodiment of the present invention.

FIG. 6

is a top view illustrating the interior of the rotary connector

201

.

FIG. 7

is a cross-sectional view taken along line SB—SB of FIG.

6

.

FIG. 8

is a side view of the rotary connector

201

, and

FIG. 9

is a top view of a bottom housing of the rotary connector

201

.

As shown in

FIGS. 6

to

9

, the rotary connector

201

has much the same configuration as the first embodiment described above. In other words, the rotary connector

201

has a rotor

205

rotatably supported on a stationary housing

203

.

The stationary housing

203

includes an upper housing

207

and a bottom housing

209

. The upper housing

207

has a plurality of engagement lugs

211

arranged in a circumferential direction, and the bottom housing

209

has a plurality of resilient tongues

213

corresponding to the engagement lugs

211

. The resilient tongues

213

have engagement windows

215

formed therein that are engaged with the engagement lugs

211

. When the engagement lugs

211

engage the engagement windows

215

formed in the resilient tongues

213

, the housing

207

is coupled to the bottom housing

209

.

The upper housing

207

and bottom housing

209

have terminal-accommodating recesses

219

a

and

219

b

, respectively, on their side walls. The bottom housing

209

has a small-current connector

221

located under the terminal-accommodating recesses

219

a

and

219

b.

Grooves

223

are formed in an inner bottom surface of the bottom housing

209

by removing off excess material. The grooves

223

include three concentric annular grooves with the rotor

205

at their center. The grooves

223

are intended to store abrasion particles produced within the stationary housing

203

and foreign materials entered from outside. The grooves

223

can be any shape and any number, provided that they serve to perform their intended function. A bearing portion

225

is formed in an inner circumferential surface of the bottom housing

209

.

The rotor

205

has connectors

227

a

and

227

b

. The rotor

205

also has an engagement pin

229

on its upper surface. The connectors

227

a

and

227

b

fit to their mating connectors provided on the underside of a steering wheel

231

, thereby being connected to electrical apparatuses on the steering wheel

231

. Just as in the previously described embodiments, the electrical apparatuses include, for example, an air bag apparatus or an alarm provided to the steering wheel, a shift-down switch and a shift-up switch for an automatic transmission, an ASCD (auto speed control device) switch, and an audio switch. The engagement pin

229

is of the construction in which the engagement pin

229

engages recesses formed in the steering wheel

231

, and the rotor

205

rotates together with the steering wheel

231

.

The rotor

205

has an upper stepped portion

231

and a lower stepped portion

233

that are formed in an upper outer circumferential surface of the rotor

205

, and a stepped portion

235

that is formed in a lower outer circumferential surface of the rotor

205

. The upper stepped portion

231

engages an inner circumferential edge

237

of the upper housing

207

, while the stepped portion

235

of the rotor

205

engages the bearing portion

225

of the bottom housing

209

. Thus, the structure is such that the rotor

205

is rotatably supported on the stationary housing

203

.

The space defined by the stationary housing

203

and the rotor

205

accommodates a floating spacer

239

. A plurality of engagement straps

241

, disposed in a circumferential direction on an upper inner circumferential surface of the floating spacer

239

, are engaged with the lower stepped portion

233

, so that the floating spacer

239

has space on its upper and lower sides and left and right sides in the stationary housing

203

. The floating spacer

239

has a pair of gaps

243

a

and

243

b.

Just as in the previously described embodiment, a set

244

of flat cables is wound around the inner and outer circumferential surfaces of the floating spacer

239

. In other words, the set

244

of flat cables includes a first flat cable

245

a

and a second flat cable

245

b

. The first flat cable

245

a

and second flat cable

245

b

have at their one ends fixed-end terminals

247

a

and

247

b

, respectively, and at their other ends rotating-end terminals

249

a

and

249

b

, respectively.

The first flat cable

245

a

makes about ¾ of one complete run starting from the fixed-end terminal

247

a

and continuing to a mid folding portion

251

a

of the first cable

245

a

which passes through a gap

243

a

in the floating spacer

239

. The first flat cable

245

a

then folds back to make about one complete run along the inner circumferential surface of the floating spacer

239

to reach the rotating-end terminal

249

a.

The second flat cable

245

b

starts from the fixed-end terminal

247

b

and continues to a mid folding portion

251

b

. The mid folding portion

251

b

of the second cable

245

b

passes through a gap

243

b

in the floating spacer

239

. The second flat cable

245

b

then folds back to make about one complete run along the inner circumferential surface of the floating spacer

239

to reach the rotating-end terminal

249

b.

The fixed-end terminals

247

a

and

247

b

are accommodated in terminal-accommodating recesses

219

a

and

219

b

, respectively. The terminal elements of the terminals

247

a

and

247

b

are exposed in the small-current connector

221

. The rotating-end terminals

249

a

and

249

b

are held by the connectors

227

a

and

227

b

on the rotating ends, respectively.

Thus, with the example shown in

FIGS. 6

to

9

, electric power can be supplied to the steering wheel

231

side from the power supply side through the set

244

of flat cables without being interfered by the operation of the steering wheel.

There is a possibility that due to a closed space defined by the stationary housing

203

and rotor

205

, abrasion particles produced by friction at various parts and foreign materials entered during the assembly process may enter the space between the bearing portion

225

and the stepped portion

235

to create abnormal sounds or require a larger driving torque.

There is another possibility that abrasion particles and foreign materials may be deposited on the set

244

of flat cables, so that abnormal sounds may be produced or increase the required driving toque due to the friction between the flat cables

245

a

and

245

b

and between the flat cables and the floating spacer

239

.

There is still another possibility that abrasion particles and foreign materials enter the gaps

243

a

and

243

b

of the floating spacer

239

to increase the friction between the first and second flat cables

245

a

and

245

b

leading to breaking of the first and second flat cables

245

a

and

245

b.

Thus, in this example, the grooves

223

of the bottom housing

209

store abrasion particles produced in the rotary connector and foreign materials entered from outside. As a result, the chances of the abrasion particles and foreign materials entering the bearing portion

225

and stepped portion

235

are minimized, and the particles and foreign materials are prevented from being deposited to the set

244

of flat cables and from entering the gaps

243

a

and

243

b

of the floating spacer

239

.

Thus, abnormal sounds and an increase in driving torque can be minimized, preventing the set

244

of flat cables from breaking. Further, the grooves

223

reduce an area through which the flat cables

245

a

and

245

b

contact the surface of the bottom housing

209

at the folding portion

251

a

, thereby reducing the sliding sounds created between the surface and the flat cables

245

a

and

245

b.

Providing the grooves

223

of the aforementioned construction on the bottom housing

47

of the rotary connector

1

of the first embodiment described above offers the same advantages as in the presently described embodiment. Because the bottom housing

47

has the stationary contacts

57

a

and

57

b

, the grooves

223

can be formed between the stationary contacts

57

a

and

57

b

, on the inner side of the stationary contact

57

a

, and on the outer side of the stationary contact

57

b.

The present embodiment can be modified while still offering the same advantages as the previously described embodiment. That is, a flange is provided on the rotor

205

to extend above the floating spacer

239

. The flange has an annular movable contact. An annular stationary contact is provided between the grooves

223

in the bottom housing

209

. The floating spacer

239

supports floating contacts thereon just as in the previously described embodiment. Thus, the modification of the present embodiment can still offer the same advantages as the previously described embodiment. In this case, the grooves

223

may be omitted.

The structure of the present invention has been described above. The main features and advantages of the invention will now be summarized.

As described above, the rotary connector of the present invention has a stationary member supported on the body of an automobile, and a rotative member that can rotate together with a steering wheel. Operating the steering wheel causes the rotative member to rotate together with the steering wheel. Then, a cable end portion, electrically connected to electrical apparatuses on the steering wheel side, moves while rotating together with the rotative member. The flat cable has a mid folding portion that passes through a gap in a floating spacer so that the flat cable folds back and is wound around an outer circumferential surface and an inner circumferential surface of the floating spacer, the flat cable lying between the stationary member and the rotative member.

Therefore, through the pivotal floating movement of the floating spacer that follows the rotation of the rotative member, an amount of slack in the flat cable allows the cable end portion, electrically connected to electrical apparatuses on the steering wheel side, to smoothly rotate together with the rotative member, the cable end portion rotating relative to another cable end portion that is supported on the stationary member and connected to the power supply.

Thus, electric power can be supplied to small-current electrical apparatuses such as an air bag and an alarm mounted on the steering wheel, a shift-down switch and a shift-up switch of an automatic transmission, an ASCD (automatic speed control device) switch, and an audio switch through the flat cables from the power supply side independently of the operation of the steering wheel.

Moreover, the floating contact provided on the floating spacer is in contact with the stationary contact on the stationary member and the movable contact on the rotative member, so that when the floating spacer performs pivotal floating movement, the floating contact can be in contact with the stationary contact and movable contact at all times. Thus, the floating contact, stationary contact, and movable contact form a slip ring mechanism, increasing the number of electrical paths so that more electrical apparatuses can be mounted on the steering wheel.

If the slip ring mechanism is designed to be capable of carrying a larger current than the flat cable, such a large current can be supplied independently of the operation of the steering wheel through the stationary contact, floating contact, and movable contact from the power supply to electrical apparatuses such as a handle heater, which usually consumes a larger current exceeding the current capacity of the flat cables on the steering wheel side. This structure does not require a large current to flow through the flat cables, thereby protecting the flat cables.

Because the floating contact is provided to the floating spacer, space can be efficiently utilized so that the overall apparatus need not be larger, and therefore, the slip ring mechanism having the stationary contact, movable contact, and floating contact can be accommodated in the housing of the rotary connector that accommodates a flat cable.

This structure prevents dust and particles from entering the rotary connector from outside and being deposited on the contacts to cause poor contact, and minimizes leakage of sliding sounds of the movable contact to the outside of the rotary connector.

According to another aspect of the present invention, the floating contact provided to the floating spacer resiliently contacts the annular stationary contact on the stationary member and the annular movable contact on the rotative member. When the floating spacer performs pivotal floating movement, the floating contact resiliently contacts the annular stationary contact and movable contact at all times.

Thus, because the stationary contact on the stationary member and the movable contact on the rotative member are formed in an annular shape, the stationary contact and movable contact can be made thin, so that the stationary contact and movable contact can be accommodated without having to increase the gap between the stationary member and the floating spacer and the gap between the rotative member and the floating spacer. Thus, the overall thickness of the rotary connector will not increase.

The floating spacer accommodates the floating contact that is in resilient contact with the stationary contact and movable contact and occupies space in a direction of thickness of the rotary connector. Thus, a slip ring mechanism that includes the stationary contact, movable contact, and floating contact can be formed by efficiently utilizing space without making the overall size of the rotary connector larger.

The slip ring mechanism, which includes the stationary contact, movable contact, and floating contact, can be provided in a space defined by the stationary member and the rotative member. This structure inhibits the sliding sounds created by the stationary contact, movable contact, and floating contact from leaking to the outside of the rotary connector, substantially preventing the vehicle driver from hearing the sliding sounds.

According to another aspect of the present invention, the contact receiving recess is formed in the floating spacer, and receives the floating contact therein. The contact receiving recess allows two opposed ends of the floating contact to expose to the stationary contact and the movable contact, so that the two opposed ends resiliently contact the stationary contact and the movable contact. Thus, the space in the floating spacer is efficiently utilized so that the floating contact can be provided in the floating spacer, ensuring that the overall size of the rotary connector is not made larger.

Because the contact receiving recess receives the floating contact reliably, the opposed ends of the floating contact can be in reliable resilient contact with the stationary contact and movable contact, thereby ensuring that electric power is supplied to the electrical apparatuses on the steering wheel side.

According to another aspect of the present invention, the urging force of the spring between the two opposed ends ensures that the contacts at the two opposed ends are in resilient contact with the stationary contact and movable contact. Moreover, the contacts at the two opposed ends can be made electrically continuous by using an electrically conductive spring.

While preventing the overall size of the rotary connector from becoming large, electric power can be supplied from the power supply side to the electrical apparatuses on the steering wheel side through the stationary contact, floating contact, and movable contact independently of the operation of the steering wheel. The contact receiving recess can be in the shape of a through-hole, so that the floating spacer can be manufactured easily. The floating contact is not polarized and has no special orientation, so that the floating contact can be assembled readily.

While the invention has been specifically described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.

Number	Name	Date	Kind
3479632	Galles	Nov 1969	A
4702705	Hirano et al.	Oct 1987	A
5470236	Wissler	Nov 1995	A
5588843	Sobhani	Dec 1996	A
5690498	Sobhani	Nov 1997	A
6039588	Osawa	Mar 2000	A
6095836	Bolen et al.	Aug 2000	A
6264487	Taniuchi et al.	Jul 2001	B1
6371779	Matsumoto	Apr 2002	B2
6471529	Oishi	Oct 2002	B2

Number	Date	Country
3-55955	Aug 1991	JP
2001-1961145	Jul 2001	JP

Rotary connector having slip ring mechanism

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

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US

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Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (10)

Foreign Referenced Citations (2)