Housing including snap-fit connection between housing components

A vehicle seat actuator includes an electric motor and a gear set that connects the drive motor to the seat and transmits the output of the motor to the vehicle seat. The drive motor and gear set are each disposed in an individual, dedicated housing component. The individual housing components are then assembled together to provide the actuator. The housing components are maintained in the assembled configuration using snap fit mechanical fasteners. Each snap-fit fastener includes a receiving portion provided on one housing component and an insertion portion provided on the other housing component. The receiving portion may be a slot formed in the gear housing that is partially obstructed by an elastic member, while insertion portion is an ear that protrudes from an outer surface of the drive motor housing and forms both a snap-fit engagement with the elastic member and a press-fit engagement with the slot.

BACKGROUND

Actuators such as those used to adjust seat position within a vehicle may include an electric motor and a gear set. The gear set connects the drive motor to the vehicle seat, and transmits the output of the motor to the vehicle seat. The drive motor and gear set may be fabricated separately and disposed in individual housing components. The individual housing components are then assembled together to provide the actuator. The housing components are maintained in the assembled configuration using mechanical fasteners such as screws. However, using screws to secure housing elements together may increase the number of parts that form the assembly and increase manufacturing steps and complexity. Increased number of parts and manufacturing complexity results in an increased actuator cost.

A need exists for an actuator housing that has fasteners that securely join the housing components, while reducing the number of parts that form the actuator assembly and reducing manufacturing complexity.

SUMMARY

In some aspects, a housing assembly includes a first housing portion and a second housing portion that is secured to the first housing portion via a fastener. The fastener includes an ear that that protrudes from a sidewall of the first housing portion in a direction perpendicular to the sidewall, a slot that is formed in a housing surface of the second housing portion and an elastic latch that protrudes into the slot so as to at least partially obstruct the slot. When the second housing portion is assembled with the first housing portion, the ear is press fit in the slot and the latch forms a snap-fit engagement with portion of the peripheral edge of the ear in such a way as to prevent withdrawal of the ear from the slot.

In some embodiments, the ear is configured to be inserted into the slot via a relative rotation between the first housing portion and the second housing portion.

In some embodiments, the second housing portion includes an internal vacancy that communicates with the slot, and the latch is cantilevered from a surface of the vacancy in such a way as to protrude into the slot.

In some embodiments, the surface of the vacancy is parallel to and spaced apart from the slot, and the latch is curved and protrudes from the surface in such a way as to overlie the surface.

In some embodiments, the latch is configured to be deflected into the vacancy by the ear when the ear is partially inserted into the slot, and to elastically return to an undeflected configuration when the ear is fully inserted into the slot.

In some embodiments, the latch includes a fixed end that is secured to the second housing portion, a free end that is spaced apart from the fixed end, and a hook portion disposed at the free end, wherein the hook portion protrudes from surface of the latch in such a way as to define a shoulder.

In some embodiments, the latch is an elastic member having an arc shape between a fixed end that is secured to the second housing and a free end that is opposed to the fixed end, the latch including a hook portion at the free end that is configured to engage the peripheral edge of the ear.

In some embodiments, the first housing portion includes a first end that is closed, a longitudinal axis that is perpendicular to the first end, a sidewall that protrudes from and surrounds the first end and is parallel to the longitudinal axis, a second end that is opposed to the first end, and a flange the protrudes outward from the sidewall at the second end. The second housing portion includes a wall structure having an inner surface, an outer surface and a wall structure open end, the wall structure open end facing the first housing portion second end. In addition, the second housing portion includes a pillar that adjoins the wall structure and includes the housing surface. The pillar protrudes beyond the wall structure open end in a direction parallel to the longitudinal axis and includes an end face that is parallel to and spaced apart from the wall structure open end. The pillar is configured so that the housing surface faces the longitudinal axis. The ear includes an enlarged portion of the flange, and the slot is provided in the housing surface of the pillar at an axial location between the wall structure open end and the pillar end face.

In some embodiments, the sidewall comprises a pair of planar sidewall portions joined at each end by a pair of curved sidewall portions, and the ear protrudes outward from the sidewall in a direction away from the longitudinal axis, and is disposed along one curved sidewall portion of the pair of curved sidewall portions. In addition, the wall structure comprises a pair of planar wall portions joined at each end by a pair of curved wall portions, and the pillar is disposed on an outer surface of the wall structure at a location along one curved wall portion of the pair of curved wall portions so as to be longitudinally aligned with the ear.

In some embodiments, the first housing portion includes a closed end, a longitudinal axis that is perpendicular to the closed end, and a sidewall that protrudes from and surrounds the closed end and is parallel to the longitudinal axis. The sidewall includes a pair of planar sidewall portions joined at each end by a pair of curved sidewall portions. The first housing portion also includes an open end that is opposed to the closed end, and a flange the protrudes outward from the sidewall at the open end. The ear protrudes outward from the sidewall in a direction away from the longitudinal axis, and is disposed along one curved sidewall portion of the pair of curved sidewall portions.

In some aspects, a fastener is configured to join a first housing portion to a second housing portion. The fastener includes a receiving portion and an insertion portion that is received in, and engages with, the receiving portion. The insertion portion includes an ear that protrudes from a sidewall of the first housing portion. The ear protrudes in a direction perpendicular to the sidewall. The receiving portion includes a housing surface of the second housing portion. The housing surface is configured to face the sidewall, and the housing surface has a slot formed therein. The receiving portion includes an elastic latch that is disposed in the slot so as to at least partially obstruct the slot. When the insertion portion is assembled with the receiving portion, the ear is press-fit into the slot, and the latch forms a snap-fit engagement with a peripheral edge of the ear in such a way that the ear is prevented from being withdrawn from the slot.

In some embodiments, the fastener is configured so that when the first housing portion and second housing portion are relatively rotated in a first direction about an axis that is parallel to the sidewall, the ear is moved relative to the slot between an initial position in which the ear is positioned external to the slot and in alignment with the slot, and a final position in which the ear is in the slot and the ear is engaged with the latch.

In some embodiments, the first housing and second housing are configured to be relatively rotated in the first direction about the axis that is parallel to the sidewall in such a way that the ear is movable relative to the slot from the initial position, in which a leading edge of the ear is positioned external to the slot and in alignment with the slot, to an intermediate position, in which the ear is in the slot and the leading edge of the ear contacts a ramp portion of the latch and causes the latch to deflect out of the slot. In addition, the ear is movable relative to the slot from the intermediate position to the final position, in which the ear is in the slot and a trailing edge of the ear is engaged with a hook portion of the latch.

In some embodiments, the first housing portion and the second housing portion are configured so that once the ear is moved relative to the slot to the final position, relative rotation of the first housing portion and the second housing portion in a second direction about the axis is prevented via the engagement of the ear with the hook portion, where the second direction is opposed to the first direction.

In some embodiments, the second housing portion includes an internal vacancy that communicates with the slot, and the latch is cantilevered from a surface of the vacancy in such a way as to protrude into the slot.

In some embodiments, the latch is configured to be deflected into the vacancy by the ear when the ear is partially inserted into the slot, and to elastically return to a non-deflected configuration when the ear is fully inserted into the slot.

In some embodiments, the latch is an elastic member having an arc shape between a fixed end that is secured to the second housing and a free end that is opposed to the fixed end. The latch includes a hook portion at the free end that defines a shoulder, and the shoulder is configured to engage an edge of the ear.

In some embodiments, the first housing portion includes a first end that is closed, a longitudinal axis that is perpendicular to the first end, a sidewall that protrudes from and surrounds the first end and is parallel to the longitudinal axis, a second end that is opposed to the first end, and a flange the protrudes outward from the sidewall at the second end. In addition, the second housing portion includes a wall structure having an inner surface, an outer surface and a wall structure open end, the wall structure open end facing the first housing portion second end, and a pillar that adjoins the wall structure and includes the housing surface. The pillar protrudes beyond the wall structure open end in a direction parallel to the longitudinal axis and includes an end face that is parallel to and spaced apart from the wall structure open end. The pillar is configured so that the housing surface faces the longitudinal axis. The ear comprises an enlarged portion of the flange, and the slot is provided in the housing surface of the pillar at an axial location between the wall structure open end and the pillar end face.

In some embodiments, the sidewall comprises a pair of planar sidewall portions joined at each end by a pair of curved sidewall portions. The ear protrudes outward from the sidewall in a direction away from the longitudinal axis, and is disposed along one curved sidewall portion of the pair of curved sidewall portions. The wall structure comprises a pair of planar wall portions joined at each end by a pair of curved wall portions, and the pillar is disposed on an outer surface of the wall structure at a location along one curved wall portion of the pair of curved wall portions so as to be longitudinally aligned with the ear.

In some embodiments, the first housing portion includes a closed end, a longitudinal axis that is perpendicular to the closed end, and a sidewall that protrudes from and surrounds the closed end and is parallel to the longitudinal axis. The sidewall includes a pair of planar sidewall portions joined at each end by a pair of curved sidewall portions. The first housing portion includes an open end that is opposed to the closed end, and a flange the protrudes outward from the sidewall at the open end. The ear protrudes outward from the sidewall in a direction away from the longitudinal axis, and is disposed along one curved sidewall portion of the pair of curved sidewall portions.

In some aspects, an actuator such as those used to adjust seat position within a vehicle includes an electric motor and a gear set that connects the drive motor to the vehicle seat and transmits the output of the motor to the vehicle seat. The drive motor and gear set are each disposed in an individual, dedicated housing component. The individual housing components are then assembled together to provide a housing assembly that houses the actuator. The housing components are maintained in the assembled configuration using snap fit mechanical fasteners. Use of snap-fit mechanical fasteners can be advantageous since the snap fit fastener components may be formed integrally with the corresponding housing components in an injection molding process. In addition, fewer parts are included in the assembly and housing assembly is simple and can be performed without tools.

In some aspects, the snap-fit fastener includes a receiving portion provided on one housing component (for example, the gear housing) and an insertion portion provided on the other housing component (for example, the drive motor housing). The receiving portion may be an elongated slot that is formed in the gear housing and that is partially obstructed by an elastic member that includes a latching feature. The insertion portion may be an ear that protrudes from an outer surface of the drive motor housing. In use, rotation of the drive motor housing relative to the gear housing allows the ear to pass into the slot in a press fitted configuration. When the ear is disposed in the slot, the latching feature of the elastic member engages a trailing edge of the ear and forms a snap-fit engagement with the ear. Advantageously, since the ear is received in the slot in a press-fit configuration, the connection between the gear housing and the drive motor housing is secure and without relative play. Further advantageously, the snap fit engagement of the elastic member with the ear serves to retain the ear within the slot. As a result of these features, the connection between the gear housing and the drive motor housing is strong, durable and reliable.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, an actuator1such as those used to adjust the position of a vehicle seat5may include an electric drive motor10, and a gear set20that is disposed between the drive motor10and vehicle seat5. The gear set20transmits the output of the drive motor10to the vehicle seat5. The drive motor10and the gear set20are housed in an actuator housing2. The actuator housing2includes a gear housing22that receives the gear set20and supports the gear set20for rotation. The actuator housing2also includes a drive motor housing12that is formed separately from the gear housing22, and is attached thereto during assembly of the actuator1. The drive motor housing12is joined to the gear housing22at one end thereof using snap fit mechanical fasteners50, as discussed in detail below.

In the illustrated embodiment, the actuator housing2includes two snap fit mechanical fasteners50, e.g., a first fastener50(1) and a second fastener50(2). The first and second fasteners50(1).50(2) are structurally identical, so only one fastener, referred to hereinafter as fastener50, will be described.

Referring toFIGS. 3-7, the fastener50includes an insertion portion60, and a receiving portion80that forms both a snap-fit engagement and a press-fit engagement with the insertion portion60. In the illustrated embodiment, the insertion portion60is provided on the drive motor housing12, and the receiving portion80is provided on the gear housing22, but the fastener50is not limited to this configuration. For example, in other embodiments, the insertion portion60may be provided on the gear housing22, and the receiving portion80may be provided on the drive motor housing12. The insertion portion60and the receiving portion80will be described in detail below.

The drive motor housing12is a cup-like enclosure that includes a sidewall14having a closed end13and an open end15. The sidewall14surrounds a longitudinal axis11of the drive motor housing12, and the longitudinal axis11extends between the sidewall open and closed ends13,15. The sidewall14has four sides that include a pair of outwardly-curved sidewall portions16that are joined by a pair of planar sidewall portions17. The sidewall open end15is opposed to the closed end13, and is surrounded by a flange18. The flange18protrudes outwardly from an outer surface of the sidewall14in a direction perpendicular to the longitudinal axis11. The flange18includes a pair of insertion portions60of the fasteners50. The insertion portions60are provided on diametrically opposed sides of the sidewall open end15. In particular, each insertion portion60includes an ear62that consists of an enlarged portion of the flange18that has a generally circular profile when viewed in a direction parallel to the longitudinal axis11. An ear62is provided on the flange18along each outwardly-curved sidewall portion16. Each ear62is positioned along the outwardly-curved sidewall portion16so as to be adjacent to a planar sidewall portion17. Each ear62has a peripheral edge64, and a through-hole63that is partially surrounded by the ear peripheral edge64.

The gear housing22includes a container24that receives the gear set20, and a cover25that closes an open end of the container24. The gear housing22also includes a fixture26that is provided at one end of the container24and that is configured to enable the gear housing22to form a secure and stable connection with the drive motor housing12. The fixture26includes a wall structure27that protrudes outward from an outer surface23of the container24and has a profile or shape that is similar to that of the drive motor housing sidewall14. In particular, the fixture wall structure27has four sides that include a pair of outwardly-curved wall portions38that are joined by a pair of planar wall portions39. In addition, the fixture wall structure27has an open end35that faces the drive motor housing open end15, and that is configured to receive and form a connection with the drive motor housing12via the fasteners50. The fixture wall structure27also includes a pair of rectangular pillars28that are formed on diametrically opposed sides of the fixture wall structure27. More specifically, a pillar28adjoins an outer surface of the fixture wall structure27along each outwardly-curved wall portion38. Each pillar28is positioned along the outwardly-curved wall portion38so as to be adjacent to a planar wall portion29. The pillars28are positioned so as to be in alignment with the ears62of the drive motor housing flange18upon assembly of the drive motor housing12with the gear housing22.

In addition, each pillar28has an inward-facing surface30that faces the longitudinal axis11. The inward-facing surface30is curved to correspond to the curved shape of the outwardly-curved wall portion38that it adjoins. Each pillar28protrudes beyond the wall structure open end35in a direction parallel to the longitudinal axis11, and each pillar28includes an end face29that is parallel to and spaced apart from the wall structure open end35.

Each pillar28provides a receiving portion80of the fastener50. The receiving portion80includes a slot82that is formed in the inward-facing surface30of the pillar28, a vacancy83that is provided inside the pillar28that communicates with the slot82, and an elastic latch86that is disposed in the vacancy83in such a way as to protrude into the slot82and at least partially obstruct the slot82. In particular, the slot82is provided in the inward-facing surface30of the pillar28at an axial location between the wall structure open end35and the pillar end face29. As a result, the slot82opens facing the drive motor housing12and the longitudinal axis11. The slot82is rectangular in shape, and is elongated within a plane P that is perpendicular to the longitudinal axis11. The slot82intersects a lateral surface31of the pillar28, providing a slot inlet81in the pillar lateral surface31. The slot82is shaped and dimensioned to receive the ear62in a press-fit manner. For example, the dimensions of the slot82and the ear62, in a direction parallel to the longitudinal axis11, are set so that the slot82to forms an interference fit with the ear62.

The pillar28includes an inner surfaces that define the vacancy83in such a way that the vacancy82terminates at a blind end85. The blind end85forms a bottom surface of the vacancy83with respect to the orientation of the actuator1shown inFIG. 6, is spaced apart from the slot82and extends in parallel to the plane P.

The latch86is an elongate, curved member having a fixed end87that protrudes from the vacancy blind end85. In addition, the latch86has a free end88that is opposed to the fixed end87. In some embodiments, the latch86is cantilevered from the blind end85in such a way that latch86overlies the blind end85and the free end88protrudes into the slot82. The latch86has a varying thickness at the free end88whereby a hook portion89is defined at the latch free end88. The hook portion89includes an angled surface92extends between a hook tip90that defines a terminus of the latch86and a hook shoulder91. The hook shoulder91protrudes from a surface of the latch86, and is configured to engage the peripheral edge64of the ear62, as discussed further below. The latch86is oriented within the vacancy83such that the hook portion89resides within the slot82with the hook tip90disposed in the slot inlet81. The latch86is sufficiently elastic to be deflected into the vacancy83by the ear62when the ear62is partially inserted into the slot82, and to elastically return to an non-deflected configuration when the ear62is fully inserted into the slot82, as discussed further below. In addition, the latch86is sufficiently rigid to engage the ear peripheral edge64upon full insertion of the ear62into the slot82, and to prevent the ear62from retracting from the slot82.

During assembly of the drive motor housing12with the gear housing22, the drive motor housing12is arranged so that the open end15of the drive motor housing sidewall14faces the fixture wall structure open end35. In addition, each ear62is positioned adjacent to a slot inlet81of a corresponding pillar28. The gear housing22and the drive motor housing12are then relatively rotated about the longitudinal axis11in a first direction (for example, a counter clockwise direction when viewed in a direction parallel to the longitudinal axis11), whereby each ear62is inserted into the respective slot inlet81. Since the hook portion89resides within the slot82with the hook tip90disposed in the slot inlet81, as the ear62advances into the slot82, the leading edge portion65of the ear peripheral edge64contacts the hook portion angled surface92and urges the latch86to deflect toward the vacancy blind end85. The deflection of the latch86allows the ear62pass over the hook portion89and to enter the slot82. As the gear housing22and the drive motor housing12are relatively rotated about the longitudinal axis11in the first direction, the ear62moves relative to the slot82from the slot inlet81to a location in which the ear62is fully disposed within the slot82. When the ear62is fully disposed within the slot82, the latch86elastically returns to an non-deflected configuration, in which the hook portion89is disposed in the slot82. In this configuration, the shoulder91of the latch hook portion89engages the trailing edge portion66of the ear peripheral edge64. Since the shoulder91is engaged with the ear peripheral edge64, relative rotation of the drive motor housing12and the gear housing22in a second direction about the longitudinal axis11is prevented, where the second direction is opposed to the first direction (for example, a clockwise direction when viewed in the same direction parallel to the longitudinal axis11). In addition, when the drive motor housing12is assembled with the gear housing22, the ear62is press fit in the slot82, which serves to further prevent withdrawal of the ear62from the slot82as well as provide a secure attachment a between the housings12,22that is free of play.

In the illustrated embodiment, the actuator housing2includes two snap-fit fasteners50(1) and50(2). It is understood, however, that a greater or fewer number of fasteners50can be used to join housing components together, and the number of snap-fit fasteners50used is determined by the requirements of the specific application.

Selective illustrative embodiments of the housing and fasteners are described above in some detail. It should be understood that only structures considered necessary for clarifying the housing and fasteners have been described herein. Other conventional structures, and those of ancillary and auxiliary components of the housing and fasteners, are assumed to be known and understood by those skilled in the art. Moreover, while a working example of the housing and fasteners have been described above, the housing and fasteners are not limited to the working examples described above, but various design alterations may be carried out without departing from the housing and fasteners as set forth in the claims.