Electric supply apparatus

The present invention is to provide an electric supply apparatus having a small size protector and being long lifetime. The electric supply apparatus having a wiring harness includes a protector; an annular wall disposed inside the protector, the wiring harness being bent freely along the annular wall; a leaf spring arranged around the annular wall, the leaf spring being fixed to the annular wall at a base end; and a spring holder disposed at a front end of the leaf spring for holding the wiring harness at a loop forming portion thereof. The spring holder is bent at a middle portion thereof with an angle in a direction of tangent of the annular wall. The spring holder fastens protective tubes of the wiring harness. The spring holder fastens end portions of a corrugated tube and a net tube which form the protective tube, and the net tube is disposed along the leaf spring.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electric supply apparatus having a wiring harness being bent freely in a protector and urged by a leaf spring to absorb sag thereof.

2. Description of the Related Art

FIGS. 13 and 14are an embodiment of a conventional electric supply apparatus, for example, JP,2002-17032,A.

The electric supply apparatus50is disposed in a sliding door41of a motor vehicle. The electric supply apparatus50has a protector42(a cover is not shown), which is made of a synthetic resin, receiving a wiring harness43flexibly, and a metal leaf spring44to urge the wiring harness43upwardly in the protector42.

A lower end portion of the leaf spring44is fixed to a forward and lower portion of the protector42together with the wiring harness43. A front end portion of the leaf spring44supports the wiring harness43slidably. The front end portion of the leaf spring44is covered with a cap49made of a synthetic resin and supports stably the wiring harness43.

The wiring harness43has a plurality of electric cables43acovered with a corrugate tube43bmade of a synthetic resin. The flexible corrugated tube43bis fixed to the protector42with a tape at a front and lower end portion.

One end portion of the electric cables43aof the wiring harness43is led out through a front portion of the protector42to auxiliary units of the sliding door41. The corrugated tube43bof the wiring harness43is wired to a vehicle body47slidably through an elongated lower opening45of the protector42and a stepping space46.

FIG. 13shows a fully closed state of the sliding door41andFIG. 14is a half opened state close to a fully opened state. The wiring harness43is pulled backwardly at the fully closed state, and pulled forwardly at the fully opened state. When the sliding door41is in the half opened state, the wiring harness tends to sag downwardly. However, the leaf spring44urges the wiring harness43upwardly to absorb the sag (excess length) and prevent to be sandwiched by other portions.

In the conventional electric supply apparatus, especially for vehicles having a large sliding distance of a sliding door41, an excess length of the wiring harness43in the protector becomes large so that the height of the protector becomes large and arrangements of other parts in the sliding door are reduced.

When the sliding door is fully closed or opened, the wiring harness43is strongly pulled so that the lifetime of the wiring harness43is reduced at the portion fixed at the protector42. The corrugated tube43bis utilized as a protective tube of the wiring harness43in the protector. However, the corrugated tube43bhas a lower flexibility compared with a net tube, not shown, made of a synthetic resin.

SUMMARY OF THE INVENTION

The present invention is to provide an electric supply apparatus having a small and compact protector, giving a higher flexibility of a wiring harness in the protector, and having a long lifetime of the wiring harness.

According to a first aspect of the invention, an electric supply apparatus having a wiring harness includes a protector; an annular wall disposed inside the protector, the wiring harness being bent freely along the annular wall; a leaf spring arranged around the annular wall, said leaf spring being fixed to the annular wall at a base end; and a spring holder disposed at a front end of the leaf spring for holding the wiring harness at a loop forming portion thereof.

Thereby, the leaf spring and loop forming portion are fixed together so that they do not slip each other. The leaf spring urges the loop forming portion directly with a restoring force and assuredly expands the loop portion. Accordingly, the electric supply apparatus can be made small size. Thereby, a tension of the wiring harness acts on the leaf spring instead of a supporting portion of the loop portion so that the lifetime of the supporting portion becomes long.

According to a second aspect of the invention, the spring holder is bent at a middle portion thereof with an angle in a direction of tangent of the annular wall.

Thereby, the bent spring holder contacts slidably and stably with the annular wall of the protector so that the loop forming portion of the wiring harness is bend freely. The loop portion is arranged in the direction of tangent of the annular wall from the spring holder so that the loop portion is not subjected to an excess flexure stress at an end of the spring holder and increases the lifetime.

According to a third aspect of the invention, the spring holder has a leaf spring holder at the bent side thereof.

Thereby, a front end of the leaf spring is attached integrally to the bent portion of the spring holder in a direction of tangent of the annular wall of the protector so as that the front end of the leaf spring is not subjected to large flexure stress. The lifetime of the spring holder increases. The leaf spring urges the loop forming portion smoothly and assuredly.

According to a fourth aspect of the invention, the spring holder fastens protective tubes of the wiring harness.

Thereby, a plurality of electric cables inside the protective tubes are freely passed through the spring holder. Since tensile force acts directly on the protective tubes, the electric cables are subjected to less tensile force.

According to a fifth aspect of the invention, the spring holder has a rib at an inner wall of a middle portion thereof and the rib extends inwardly higher than an inner face of an end portion of the protective tube.

Thereby, the electric cables are supported by the rib separately from the end of the protective tube so that the interference between them is prevented especially at the bent portion of the spring holder.

The separation is especially effective for the corrugated tube having a sharp end (cut end) utilized for the protective tube.

According to a sixth aspect of the invention, the spring holder fastens end portions of a corrugated tube and a net tube which form the protective tube and the net tube is disposed along the leaf spring.

Thereby, the corrugated tube and net tube are connected to each other through the spring holder. The net tube has more flexibility than the corrugated tube and freely bends along the leaf spring and the annular wall of the protector so that the wiring harness is bent in a small diameter.

According to a seventh aspect of the invention, the spring holder includes a first holder having ribs for engaging with grooves of the corrugated tube and a second holder for holding an insertion member attached to the net tube.

The insertion member is resin molded by applying a resin into a molding die receiving the end of the net tube. The spring holder is formed to be divided and is joined together after setting the protective tubes.

According to a eighth aspect of the invention, the spring holder has thorny protrusions to be engaged with the grooves of the corrugated tube penetrating through the net tube covering an outer face of the corrugated tube.

Thereby, a length of the spring holder is reduced by a extent of an overlapping between the corrugated tube and net tube.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1-4show an embodiment of an electric supply apparatus according to the present invention.

The electric supply apparatus1, as shown inFIG. 1, includes a protector4having a base2and a cover3made of a synthetic resin, a leaf spring6, being made of a metal, wound flexibly around an annular wall5disposed inside the base2, a wiring harness7arranged around the annular wall5to form a loop portion8, and a spring holder9, being made of a synthetic resin and holding a front end of the leaf spring6, for fastening a middle portion of the wiring harness7in a longitudinal direction, or a part of the loop portion8. The electric supply apparatus1is mounted to a sliding door, not shown, of a motor vehicle.

The base2and cover3of the protector4each have a triangle or trapezoidal base plate10,11and a peripheral wall12,13respectively. The each peripheral wall12,13has a vertical front wall12a,13a, a horizontal upper wall12b,13band a sloping rear wall12c,13crespectively. When the cover3is covered to the base2, the peripheral wall13of the cover3is positioned around and outside the peripheral wall12of the base12and an elongated opening14is formed at a lower end of the protector4for guiding out the wiring harness7.

A wiring harness guiding wall15with a curved section extends outwardly from the lower opening14of the cover3. An annular wall16is disposed at the center of the cover3and protrudes toward the base side for engaging with and inside the annular wall5of the base2. The protector4is shorter in height than the conventional one (FIG. 13). This is because the wiring harness7is received in a loop form manner. The protector4is fixed vertically to the sliding door with brackets17.

The annular wall5is disposed at about the center of the base2. A spring holder18is integrally disposed at a rear side of the annular wall5, or at the left side ofFIG. 1. As shown inFIGS. 2-4, a narrow wiring harness lead-out19is disposed at the base plate10and adjacent to the rear side of the spring holder18, and is connected to a U-shaped groove20. The U-shaped groove20is located inside a gutter21extending outwardly from the base plate10. A cutout22is formed in the peripheral wall12of the base2intersecting with the U-shaped groove20. A curved wiring harness guiding wall23is disposed adjacent to the rear side of the wiring harness lead-out19and extends from an upper portion of the annular wall5with an @-shaped character. In the description, the front and rear of the electric supply apparatus1correspond to those of the motor vehicle.

A base end of the leaf spring6is press inserted into a slit24and fixed to the spring holder18. The leaf spring6is disposed around about three quarters of the annular wall5and has an outward restoring force. Refer toFIGS. 1 and 2. The leaf spring6is straight without restriction and is bent resiliently to be set to the base2.

The wiring harness7is arranged around the annular wall5and the leaf spring6in the loop manner. One end7aof the wiring harness7is upwardly led out through the U-shaped groove20and fixed to the gutter21and arranged in a sliding door to connect auxiliary units such as power window unit, door lock unit or mirror unit (not shown). The other end7bof the wiring harness7is arranged into a vehicle body from the guiding wall23through the lower opening14. A corrugated tube25of the wiring harness7can move freely inside the base plate10independently of a net tube portion7a(26) inside the groove20.

The spring holder9is fixed to the front end of the leaf spring6and the protective tubes25,26of the loop portion8of the wiring harness7are fixed to the spring holder9. The protective tubes of the present invention include the net tube26and the corrugated tube25. The net, or knitted, tube26made of a synthetic resin is arranged from the groove20to the spring holder9along the annular wall5. The corrugated tube25made of a synthetic resin is arranged from the spring holder9to the vehicle body through the lower opening14. The net tube26and the corrugated tube25are connected to each other through the spring holder9.

The net tube26is more flexible than the corrugated tube25. The corrugated tube25has more rigidity than the net tube26and safely protects the wiring harness7from outside interference. The corrugated tube7of the embodiment has an oval section, the long axis of which is arranged parallel to the base plate10. The wiring harness7includes the protective tubes25,26and a plurality of electric cables27received therein.

The spring holder9is a nearly V-shaped form, the open portion of V facing to the annular wall5, and can move freely around the annular wall5. The spring holder9has a first receiver face28aand a second receiver face29afacing to the annular wall5. Both receiver faces28a,29aintersect obtusely each other. When the first receiver face28acontacts with an outer face of the annular wall5, the second receiver face29aconcurrently contacts with the outer face of the annular wall5so that the spring holder9can move freely around the annular wall5by means of the intersecting receiver faces28a,29a.

The corrugated tube25is fixed at a first holder28having the first receiver face28aand the net tube26is fixed at a second holder29having the second receiver face29a. An outer face opposing to the receiver faces28a,29aof the holder9can be a nearly V-shape or curved shape. The inner face of the holder9may have a curved or arced face instead of the reversed V-shaped face.

FIG. 2shows that a right side sliding door is fully opened. The sliding door is moved backwardly with the electric supply apparatus1. The wiring harness7is wound around the annular wall5and led out forwardly to a harness holder of the vehicle body, through the lower opening14of the protector4(the cover3not shown). The leaf spring6is curved around the annular wall5with the loop portion8of the wiring harness7and has a smallest diameter.

A tension F exerted on the wiring harness7acts on the spring holder9through the corrugated tube25and acts on the leaf spring6in a lengthwise direction thereof through the spring holder9. The metal leaf spring6is directly pulled so that the net tube26, extending from the spring holder9to the wiring harness lead-out19, and the electric cables27received therein are hardly pulled and the endurance thereof increases.

InFIG. 2, the spring holder9at the end of the leaf spring6is subjected to an upward and diagonally forward force F1due to a restoring force of the leaf spring6. The loop forming portion8of the wiring harness7is subjected to a downward and diagonally forward force F2at a middle portion of the leaf spring6due to the restoring force of the leaf spring6. The restoring force F1and expanding force F2are perpendicular to each other.

FIG. 3shows a partially opened state of the sliding door. At this state, the wiring harness7usually hangs down between the vehicle body and the sliding door. However, the restoring force F1of the spring holder9due to the leaf spring6and the expanding force F2of the leaf spring6prevent the wiring harness7from hanging down. Accordingly, the loop portion8of the wiring harness7expands outwardly the annular wall5with a large diameter from the wiring harness lead-out19. The portion7bof the corrugated tube25of the wiring harness7is returned inside the protector4through the lower opening14and the excess length is assuredly received. InFIG. 3, the restoring force F1acts forwardly and the expanding force F2acts diagonally forward and downward.

The front end of the leaf spring6is fixed to the protective tubes25,26at the loop portion8of the wiring harness7through the spring holder9. Then, an urging force of the leaf spring6acts directly on the wiring harness7so that the loop portion8assuredly expands and contracts without slipping and receives the excess length, or sag, of the wiring harness7.

InFIG. 3, when the loop portion8expands in diameter, the net tube26and the electric cables27therein are subjected to a compressive force. The compressive force is applied to the leaf spring6through the spring holder9without acting to the net tube26and the electric cables27. Accordingly, the endurance of the net tube26and the electric cables27is improved.

FIG. 4shows the sliding door fully closed. The sliding door moves to the front side of the vehicle with the electric supply apparatus1. The wiring harness7is led out to a wiring harness holder of the vehicle body, not shown, through the lower opening14of the protector4. The loop portion8expands in diameter with the leaf spring6so that the wiring harness7slides backwardly in the lower opening14when the sliding door is closed.

The leaf spring6is directly subjected to a tension exerted on the net tube26through the spring holder9. Hence, similarly to the fully opened state of the sliding door inFIG. 2, the tension is not applied to the net tube26and the electric cables27therein so that the endurance thereof is improved.

When the sliding door is opened from the closed state ofFIG. 4, the operation is reversed fromFIG. 4toFIG. 3andFIG. 2. When the sliding door is opened, the function of the leaf spring6and the spring holder9are the same as the closing operation of sliding door.

FIG. 5shows an exploded view showing an embodiment of an assembly of the spring holder9, the protective tubes25,26of the wiring harness7and the leaf spring6.FIG. 6shows a plan view of the assembled state.

As shown inFIG. 5, the spring holder9has a holder base31and holder cover32at each side. The holder base31and holder cover32are made of a synthetic resin and each has a semicircular section and bent at the center. The spring holder9has the first holder28for the corrugated tube25at one end and the second holder29for the net tube26at the other end.

The first holder28has a plurality of ribs33, two ribs in the present embodiment, arranged parallel to each other to be engaged with grooves25aof the corrugated tube25at an inner wall of the oval tube. The second holder29has a pair of ribs35opposed to each other to hold an insertion member34of the net tube26at the inner wall of the oval or circular tube. A pitch of the ribs33has n times pitch of the grooves25aof the corrugated tube25, where n is integer such as 1, 2, 3.

A fan-shaped space69is disposed between the first holder28and the second holder29. The fan-shaped space69is utilized for allowing the exposed cables27between the protective tubes25,26to pass through. The fan-shaped space69has a rib68at the first holder side and the ribs35at the second holder side. The rib68is arranged parallel to the ribs33for holding the corrugated tube25.

The holder base31and holder cover32are joined together with a locking means such as locking protrusions36and engaging frames37and form the tube having the oval section. The locking means is not limited to the embodiment shown but may employ a locking arm and a locking recess. The first receiver face28aof the first holder28are formed to be flush with the engaging frame37, the locking protrusion36engaged into the frame, and ribs38at both sides of the frame37.

The insertion member34is formed with insert molding by inserting an end of the net tube26into a synthetic resin material in a molding tool so that the insertion member34is integral with the net tube26. The ribs utilized at the first holder28can be used for engaging with grooves39disposed around the insertion member34instead of the pair of the ribs35.

A leaf spring holder51having a slit66for inserting the leaf spring6and a locking protrusion40inside the slit, seeFIG. 6, are disposed at the second receiver face29aof the second holder29of the holder base31. The holder cover32is formed not to cover the leaf spring holder51.

As shown inFIG. 6, a front end portion6aof the leaf spring6is formed narrow and has a circular engaging through-hole52to be engaged with the locking protrusion40. An opening53is disposed at the second receiver face29aof the holder base31and is opposed to the locking protrusion40. Fixing structure of the leaf spring6is same as that of conventional spring caps. An angle between the first receiver face28aof the first holder28and the second receiver face29aof the second holder29is set to contact with the outer face of the annular wall5of the protector4.

An assembling is performed as follows. The plurality of the electric cables27are inserted into the corrugated tube25and the net tube26as shown inFIG. 5. An end portion of the corrugated tube25is engaged with the first holder28of the holder base31. The insertion member34of the net tube26is engaged with the second holder29of the holder base31. The holder cover32is covered to the holder case31for locking to obtain the assembly given inFIG. 6. Then, both the protective tubes25,26are connected to each other through the spring holder9.

FIG. 7shows the assembled state of the electric cables27inserted into the spring holder ofFIG. 5. The rib68of the first holder51at the center and a bent portion of the spring holder9extends inwardly and higher than an end25d, cutting end, of the corrugated tube25. The electric cables27are supported by an end of the rib68and a gap71is formed between the end25dand the electric cables27not to contact with each other. This arrangement is same all around the rib68so as to prevent damage and wear to the electric cables27resulting from interference with the end25dof the corrugated tube25.

The ribs35of the second holder29also extend inwardly from the net tube26and are higher than that of an inner face at an end of the insertion member34. Hence, the interference between the inner face at the end of the insertion member34and the electric cables27is prevented so as to avoid damage and wear to the electric cables27. The rib35at the bent portion of the spring holder9is integral with the rib68. The insertion member34is a part of the net tube26.

In the present embodiment, the spring holder9and insertion member34are formed separately. Both the holder base31and the insertion member34or both the holder cover32and the insertion member34can be molded integrally. In this case, the net tube26is fixed with the insertion member34. The net tube26can be insert molded to the holder base31or the holder cover32without the insertion member34. Then, a number of parts is reduced and a connecting structure of the protective tubes is manufactured with low cost.

The corrugated tube25and net tube26are utilized as the protective tube in the above embodiment. As shown inFIG. 8, corrugated tubes can be disposed at both sides of the spring holder9. As shown inFIG. 9, the corrugated tube25can be disposed at the one side of the spring holder9, extending to the lower opening14of the protector4, and the plurality of the cables27without the protective tube can be disposed at the other side, extending to the wiring harness lead-out19. The flexibility of the electric cables27increases without using the protective tubes25,26.

The spring holder9ofFIG. 8has the ribs33at both the first and second holders28,29and locks the grooves25aof the each corrugated tube25.

The plurality of the cables27can be directly fixed to the spring holder9at the both sides thereof without the protective tubes25,26. In this case, the electric cables are fixed at an extension, not shown, of the spring holder with a tape or band. A clip, not shown, binding the electric cables can be locked to the spring holder.

The oval-sectioned corrugated tube25is utilized in the embodiment but a circular-sectioned corrugated tube can also be utilized. In this case, the holders are formed into a cylindrical tube having a circular section.

In the embodiment, the spring holder9is bent at the center but can be straight such as a spring holder9′ as shown inFIG. 10. In the case of the straight spring holder9′, the protective tube26, the electric cables27therein and the leaf spring6bend in a small curvature especially at the end of the second holder29noted as numeral55inFIG. 10and are subjected to a large bending stress. Therefore, the straight type spring holder9′ is only utilized for the annular wall having a large diameter. The protector cover3is omitted inFIG. 10.

In the embodiment, the net tube26is fixed to the spring holder9with the insertion member34as shown inFIG. 5.FIGS. 11 and 12show another embodiment. A plurality of thorny protrusions59are disposed inside a holder base57and holder cover58of a spring holder56. An outer face of an end portion25cof the corrugated tube25is covered with an end portion26aof the net tube26. Then, the corrugated tube25is covered with the holder base57and holder cover58over the net tube26. The thorny protrusions59penetrate into the net tube26and engage with the grooves25aof the corrugated tube25so as to connect the both protective tubes25,26. The thorny protrusions59may be engaged directly with the grooves25aof the corrugated tube25without the net tube26, which is pushed away outside the spring holder56by the thorny protrusions59.

The spring holder56is formed with a synthetic resin. The holder base57and holder cover58each have a semi-oval portion60and the thorny protrusions59are disposed at an each inner wall. The holder base57has a leaf spring holder62extending from the semi-oval portion60and a tapered protruding wall63above the leaf spring holder62. The both semi-oval portions60are locked together with locking protrusions64and engaging frames65to form a cylindrical tube having an oval section.

The thorny protrusions59are arranged in the each semi-oval portion60with an equal pitch which is n times of the pitch of the grooves25aof the corrugated tube25, where n is integer such as 1, 2, 3. The protrusions59are molded integrally with the semi-oval portions60utilizing a synthetic resin and have a triangular pyramid or conical shape.

The leaf spring holder62extends and bends from the semi-oval portion60. The second receiver face63aat the leaf spring holder62is inclined with respect to a first receiver face60aof the semi-oval portion60and extends into a direction of tangent of the annular wall5of the protector4, seeFIG. 2. The leaf spring holder62has the slit66for inserting the base end of the leaf spring6and the locking protrusion40to lock the leaf spring6as similar to the embodiment ofFIG. 6. A receiver face60aof the semi-oval portions60is flush with the engaging frame65, the locking protrusion64engaging with the frame65, and ribs67disposed at both sides of the engaging frame65.

The leaf spring holder62ofFIG. 11can be formed to extend straight from the semi-oval portion60without bending such as the leaf spring holder9′ ofFIG. 10. However, the straight type spring holder is only utilized for the annular wall5having a large diameter as described above.

In the above embodiments, the leaf spring holders51,62are disposed at the second holder29of the spring holder9, seeFIG. 5, and the protruding wall63of the spring holder56, seeFIG. 11, respectively. They can be disposed at the first holder28of the spring holder9and the semi-oval portion60of the spring holder56, respectively. In this case, especially to the embodiment ofFIG. 5, the leaf spring6is curved along the receiver face29aof the second holder29.

In the electric supply apparatus described above, the protector4is arranged vertically inside the sliding door, or sliding body. The protector4can be arranged horizontally in the vehicle body, or static body, and one end of the wiring harness7is arranged from the elongated opening14to the sliding door and the other end thereof is arranged from the wiring harness lead-out to the vehicle body. The electric supply apparatus of the present invention is also adapted to a sliding seat of a motor vehicle or sliding doors other than motor vehicles.