Protector housing comprising a first shell and a second shell

Abstract: A top shell (12) is linked to a bottom shell (13) via a hinge portion (14) and locked to the latter, so that the top shell is prevented from falling apart from the bottom shell when the hinge portion is broken. The top shell (12) is formed integrally with the bottom shell (13) via the hinge portion (14). An end portion (12d) of the top shell (12) is notched into the form of a semi-circular groove, so as to form a fixing recess (12c), whereas an end portion (13d) of the bottom shell (13) is formed into a semi-circular projection, so as to form a fixing protrusion (13c). The top shell (12) is then superposed onto the bottom shell (13), and they are locked by a locking protrusion (12a) and a locking recess (13a). At the same time, the fixing protrusion (13c) is pressfitted into the fixing recess (12c), so that the top shell (12) is immobilized at a given position relative to the bottom shell (13).

Description: The present invention relates to protector housings that can be mounted in vehicles such as automobiles. Such a protector housing usually includes a top shell and a bottom shell. In known protector housings, the top and the bottom shells are locked by a first locking means and a corresponding second locking means, bound commonly by a hinge portion. The invention concerns, in particular, a device for fixing the top shell to the bottom shell in such a protector housing. To close the protector housing, the top shell is rotated around the axis of hinge portion and superposed onto the bottom shell. After the both shells are arranged at a given position, the first locking means is fitted with the second locking means. However, the hinge portion bridging the top shell and the bottom shell is usually formed in thin gauge material which, when the protector housing is closed, may protrude from the outer frame of the protector housing. In such a configuration, the hinge portion often risks being hit by external forces and getting broken. The device according to the present invention is designed to provide immunity to such incidents, and holds the top and the bottom shells firmly together, even if the hinge portion is cut off. The inventive device thus prevents further degradation of the protector housing. The protector housings mentioned above may be electrical connector housings, wire harness housings or the like, which are installed in automobiles or in the unitary parts thereof. Such protector housings usually include a top shell that protects the open top and the inside of the bottom shell, the latter serving as a main container portion. Further, the top shell and the bottom shell are often linked together through a hinge portion integrally constructed with the shells. Fig. 1A shows a protector housing 1, e.g. wire harness housing, installed in the joint zone S connecting a flat cable FC to electrical cables D. In the protector housing 1, a top shell 2 and a bottom shell 3 are linked through a flexible hinge portion 4 integrally formed with the shells. An end portion of the top shell 2, distal to the end to which the hinge portion 4 is linked, is provided with a locking protrusion 2a having a claw portion 2b. Conversely, the bottom shell 3 is notched at a position corresponding to that of the locking protrusion 2a when closed, thereby forming a locking recess 3a. Fig. 1 (B) shows how the top shell 2 is closed and locked with the bottom shell 3 In the example, the bottom shell contains the joint zone S connecting a flat cable FC to electrical cables D. The top shell 2 is first rotated about the axis of hinge portion 4, the latter serving as fulcrum, and is superposed onto the bottom shell 3. The locking protrusion 2a is then fitted into the locking recess 3a, while the claw portion 2b is hooked to a housing base 3b. When the locking protrusion 2a of top shell 2 and the locking recess 3a of bottom shell 3 are fitted together and the claw portion 2b is hooked up, both shells require a certain degree of play or clearance. However, when the top shell 2 is locked as shown in Fig. 1B, this play may form a space K between the locking protrusion 2a and the locking recess 3 a. As a result, even after the protector housing is locked, it may still be subjected to horizontal or lateral movements (shown by arrow in Fig. 1B) caused by automobile's displacement. These movements may jolt the protector housing and loosen its structure. As shown in Fig. 1B, the hinge portion 4 is made thin so as to acquire flexibility, and protrudes from the outer frame defined by the top shell 2 and the bottom shell 3. Such a construction, however, renders the hinge portion 4 vulnerable to breakage. For instance, this portion may be easily caught by car parts or outer forces, when fitting into car bodies. In such a case, the top shell 2 may fall off the bottom shell 3, even if they are locked together. Otherwise, DE 195 17 431 C discloses a protector housing according to the preamble of claim 1, comprising a fixing protrusion and a corresponding fixing recess, but not a press-fit between these elements. In view of the above, a first object of the present invention is to provide a means for preventing the locked top shell of a protector housing from coming apart from the bottom shell thereof, even if the hinge is broken. A second object of the invention is to provide a means for preventing a loose joint being formed between the top shell and the bottom shell after they have been locked together. In order to solve the above problem, there is provided a protector housing for fixing together a first shell (e.g. top shell) and a second shell (e.g. bottom shell) in a housing, the first shell being linked integrally to the second shell via a hinge portion so as to enable a opening and closing movement. The first shell includes a locking protrusion, while the second shell includes a locking recess, so that the locking protrusion and the locking recess can be locked. The second shell further includes at least one fixing protrusion, whereas the first shell includes a corresponding fixing recess. The fixing protrusion is adapted to press-fit into the fixing recess, so that, when the locking protrusion and the locking recess are locked together, they are immobilized by the fixing protrusion and the fixing recess. In the above protector housing, the first shell and the second shell respectively include an end portion distal to the end portion to which the hinge portion is linked. Preferably, the fixing protrusion is in the form of a semi-circular column projecting from the end portion of the second shell, whereas the corresponding fixing recess is in the form of a complementary semi-circular groove located at the end portion of first shell, such that, when the first shell and the second shell are locked, the fixing protrusion fits into the fixing recess. The protector housing may be an electrical connector housing or a wire harness housing. In this manner, the second shell is provided with a fixing protrusion, whereas the first shell is provided with a fixing recess. When the first shell is locked onto the second shell and fixed, the fixing protrusion press-fits into the fixing recess, so that the first shell is immobilized on the second shell at a given position. Consequently, even if the hinge portion is broken and the first shell is subjected to biasing forces towards the locked side, the displacement of the first shell is hindered by the fixing protrusion and fixing recess. Conversely, when the first shell is subjected to biasing forces towards the hinge portion, the displacement of the first shell is prevented by the locking protrusion and locking recess. Likewise, separating forces between the two shells are impeded by the fixing protrusion and the locking protrusion. As a result, the first shell is firmly fixed to the second shell, so as to prevent the first shell from slipping-out or falling-off. Nonetheless, the first shell still retains a space for allowing play, after the housing has been locked up. Furthermore, as the fixing protrusion and the fixing recess are press-fitted, the formation of loose joints is effectively avoided. Typically, the first shell and the second shell include a hinge portion which links both shells, and a respective end portion distal thereto. The fixing protrusion is then formed on the end portion of the second shell, whereas the fixing recess is formed by notching the end portion of the first shell, such that, when the housing is closed, the fixing protrusion fits with the fixing recess. Preferably, the fixing protrusion is in the form of a semi-circular column projecting from the end portion of the second shell, whereas the fixing recess is in the form of a complementary semi-circular groove. Further, the first shell is rotatable around the axis of the hinge portion. In this structure, the fixing protrusion can easily be fitted into the fixing recess from its notched open side. Moreover, as mentioned above, the fixing protrusion may be in the form of a semi-circular column, whereas the fixing recess may be in the form of a semi-circular groove. This configuration allows both fixing means to be press-fitted very easily. However, the position at which the fixing protrusion and fixing recess are formed is not limited to the position mentioned above or shown in Fig. 2. It may also be provided at another position or at a plurality of positions, taking into account the size of the second shell. The above and the other objects, features and advantages of the present invention will be made apparent from the following description of the preferred embodiments, given as non-limiting examples, with reference to the accompanying drawings, in which: Fig. 1A is a perspective view of a prior art protective housing comprising a first shell, a second shell and a complementary locking protrusion and recess; Fig. 1B is a cross-sectional side view of the prior art protective housing of Fig. 1; Fig. 2 is a perspective view of a protector housing including a device for fixing a first shell to a second shell according to the invention; Fig. 3 is a cross-sectional side view of the protector housing of Fig. 2, showing how the first shell is rotated and fixed to the second shell; Fig. 4A is a perspective view of a fixing protrusion and a fixing recess of the protector housing of Fig. 2, before they are fitted; Fig. 4B is a perspective view of the same fixing protrusion and fixing recess, after they have been fitted; Fig. 5 is a perspective view of the protector housing of Fig. 2, when the first shell and the second shell are locked and fixed; and Fig. 6 is a perspective view of a variant protector housing which includes two sets of fixing protrusions and fixing recesses. Fig. 2 shows a protector housing 11 according to the present invention. It comprises a first shell (e.g. top shell 12), and a second shell (e.g. bottom shell 13) made of a resin, and integrally bound through a hinge portion 14. The hinge portion 14 is made thin so as to retain flexibility. As shown in Fig. 3, the top shell 12 can be closed or opened by rotation about the axis of hinge portion 14, which serves as fulcrum. The protector housing 11 is designed to contain and protect a joint zone S where a flat cable connects to electrical cables. The top shell 12 thus has a first end adjacent the hinge portion 14 and a second end 12d distal thereto. As is known from the prior art, the second end 12d of the top shell 12 is provided with a locking protrusion 12a having a claw portion 12b. The second end is further provided with a fixing recess 12c such as a notch, adjacent, but apart from, the locking protrusion 12a. As shown in Fig. 4 (A), the fixing recess 12c is prepared by cutting off the edge of the second end 12d, so that a substantially semi-circular, outwardly spreading recess is formed. The size of the fixing recess 12c is designed such that it neatly engages with a counter-part fixing protrusion 13c below, e.g. a tab, formed on the bottom shell 13. Further, the distance between the fixing recess 12c and the locking protrusion 12a can be arranged suitably, depending on, e.g. the size of the protector housing 11. Likewise, the bottom shell 13 has a first end adjacent the hinge portion 14 and a second end 13d distal thereto. The second end of the bottom shell 13 is provided with a locking recess 13a in a position corresponding to that of the locking protrusion 12a of top shell 12 when the housing 11 is closed. The locking recess 13a is formed by notching off the second end 13d in a rectangular shape. There is also provided a fixing protrusion 13c, such as a tab, at a position corresponding to that of the fixing recess 12c when the housing 11 is closed. As shown in Fig. 4 (A), the fixing protrusion 13c is in the shape of a column having a semi-circular cross-section, which is complementary to the shape of fixing recess 12c. The height of the fixing protrusion 13c corresponds to the thickness of the top shell 12. Furthermore, the radius of the semi-circle is designed such that the fixing protrusion 13c retains a required hardness. As shown in Fig. 2, the protector housing 11 covers the joint zone S connecting the flat cable FC to the electrical cables D. Then, as shown in Fig. 3, the top shell 12 is rotated onto the bottom shell 13 about the axis of the hinge portion 13 serving as fulcrum, so that the locking protrusion 12a fits into the locking recess 13a and the claw portion 12b is hooked by the housing base 13b. At the same time, the fixing protrusion 13c of bottom shell 13 fits into the fixing recess 12c of top shell 12, as shown in Figs. 4A and 4B. As the size of the fixing recess 12c is designed to match closely to the external shape of fixing protrusion 13c, the latter must be pressed into the former in order to be engaged. Moreover, the fixing recess 12c is formed by hollowing out the second end 12d of top shell 12, such that the fixing recess 12c flares outwardly. Accordingly, when the top shell 12 is closed along the path shown in Fig. 3, the fixing protrusion 13c can smoothly fit into the fixing recess 12c, without any miss-match. In Fig. 5, the top shell 12 is locked to the bottom shell 13, while the fixing protrusion 13c press-fits into the fixing recess 12c. The locking protrusion 12a and the locking recess 13a are joined while keeping a certain degree of play, as in the prior art. However, as the fixing protrusion 13c and the fixing recess 12c are press-fitted, the position of the top shell 12 becomes fixed. As a result, in spite of the presence of clearance, the top shell 12 is immobilized and the loose fit can be prevented. The hinge portion 14 may be broken by, e.g. getting caught with other automobile parts while trying to lock the top shell 12. In such a case, the press-fitting between the fixing protrusion 13c and the fixing recess 12c prevents the top shell 12 from falling off. In an example illustrated in Fig. 5, the top shell 12 is subjected to a biasing force towards the locking protrusion 12a along arrow X. However, the fixing protrusion 13c and the fixing recess 12c are firmly engaged with each other, so that the top shell 12 cannot move. Likewise, when the hinge portion 14 is broken, the top shell 12 may be subjected to a biasing force towards the broken hinge portion 14 along arrow Y. However, the locking protrusion 12a and the locking recess 13a are firmly engaged with each other, so that the top shell 12 cannot move. Further, when the top shell 12 is subjected to a biasing force along arrow Z in the axial direction of electrical cables D, the top shell 12 cannot move by virtue of the engaging force between the locking protrusion 12a and the locking recess 13a. Furthermore, the top shell 12 is also immobilized against skew forces, by virtue of the same engagement force. It follows that, even when the hinge portion 14 is damaged, the top shell 12 is prevented from falling off. In addition, the protector housing is also prevented from the vertical disengagement by virtue of the fixture between the claw portion 12b of locking protrusion 12a and the housing base 13b of the bottom shell 13. In cases where the protector housing is used for automobile parts subjected to high degrees of vibration or where its size is too large, there may be provided a pair of second fixing protrusions 13c-1' and 13c-2' with complementary second fixing recesses 12c-1' and 12c-2', both protrusions and recesses flanking a second locking protrusion 12a' and a second locking recess 13a'. Dislodging along the direction X, Y or Z may thus be securely avoided, as well as the falling-off of a second top shell 12' after the damage of a second hinge portion 14'. However, the fixing recess 12c of top shell 12 and the fixing protrusion 13 of bottom shell 13 are not limited to the configurations disclosed in the foregoing embodiments. They can also be substantially in a rectangular form, and their number can be greater. Furthermore, the device for fixing the top shell 12 and the bottom shell 13 can be used for purposes other than protecting a wire harness housing which covers the joint zone for electrical cables. It may also be used for a receptacle including an upper case and a lower case linked through a hinge, such as an electrical connector housing. As is understood from the above, when using the device for fixing the top shell and the bottom shell according to the invention, the fixing recess of top shell press-fits with the fixing protrusion of bottom shell, while the top shell is locked onto the bottom shell. The top shell is thus fixed in a predetermined position, so that dislocation of the top shell can be prevented. Moreover, the hinge binding the top shell to the bottom shell may be broken while both shells are locked. Even in such a case, the top shell is immobilized by the above-mentioned fixing devices and locking means, so that the top shell is prevented from falling off.

Claims: A protector housing comprising a first shell (12) and a second shell (13), the first shell (12) being linked integrally to the second shell (13) via a hinge portion (14) so as to enable an opening and closing movement, the first shell (12) including a locking protrusion (12a), whereas the second shell (13) includes a locking recess (13a), so that the locking protrusion (12a) and the locking recess (13a) can be locked, said second shell (13) further including at least one fixing protrusion (13c) and said first shell (12) including a corresponding fixing recess (12c), characterized in that said at least one fixing protrusion (13c) is adapted to press-fit into said corresponding recess (12c), so that, when the locking protrusion (12a) and the locking recess (13a) are locked together, they are immobilized by said at least one fixing protrusion (13c) and said corresponding fixing recess (12c). The protector housing according to claim 1, wherein the first shell (12) and the second shell (13) respectively include an end portion (12d, 13d) distal to the end portion to which the hinge portion (14) is linked, and said at least one fixing protrusion (13c) is in the form of a semi-circular column projecting from said end portion (13d) of the second shell (13), whereas said corresponding fixing recess (12c) is in the form of a complementary semi-circular groove and located at said end portion (12d) of the first shell (12), such that, when the first shell (12) and the second shell (13) are locked, said at least one fixing protrusion (13c) fits into said corresponding fixing recess (12c). A protector housing according to claim 1 or 2, wherein said protector housing is an electrical connector housing or a wire harness housing.

Inventors: MAEGAWA AKIHITO, MAEGAWA, AKIHITO, Maegawa, Akihito, Sumitomo Wiring Systems, Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2000
Main classification: B60R16
IPC codes: H01R13, H02G3, B60R16