Patent Description:
People's demands on vehicle hitching performance increase with their pursuit of a more diversified way of life. A conventional trailer hitch coupler additionally mounted to a vehicle comprises a body and a hitch, wherein the body is secured on a vehicle body of the vehicle; a rotating shaft for actuating the hitch to rotate synchronously is provided on the body. Dependent on actual needs, the hitch is rotated beneath the vehicle body to a folded position or rotated out of the vehicle body to an unfolded position for hitching.

However, in the prior art, the locking mechanism to lock the rotating shaft to prevent it from rotation when the hitch is in the unfolded position or in the folded position does not prevent sway of the hitch when the hitch is in the unfolded position and the folded position, which deteriorates hitching performance of the trailer hitch coupler.

Prior art trailer hitches are disclosed in documents <CIT>, <CIT>, <CIT> and <CIT>.

To overcome the above and other drawbacks in the prior art, embodiments of the present disclosure provide a trailer hitch coupler with good hitching performance, which can lock a hitch at a folded position and an unfolded position so as to prevent sway of the hitch, thereby enhancing hitching performance of the trail hitch coupler.

To solve the above technical problem, the present invention adopts the following technical solution:
In a trailer hitch coupler of the kind referred to, the locking member is a rotatably mounted claw, a driving slot is provided on the transmission disc, and a locking slot is provided on the driven shaft, such that when the claw is snapped into the driving slot and the locking slot, the claw locks the driven shaft from rotation; and when the transmission disc rotates to release the claw out of the driving slot and the locking slot, the claw unlocks the driven shaft to rotate.

Furthermore, the claw is provided with a torsion spring configured to drive the claw to reset; and after the claw is reset, the claw is snapped into the driving slot and the locking slot.

Furthermore, the locking slot is an arc-shaped slot, and the claw is a sectorial plate, wherein an arc-shaped surface of the sectorial plate matches the arc-shaped slot; the driving slot is a trapezoidal slot, wherein an opening of the trapezoidal slot is gradually enlarged radially outwardly; or, the arc-shaped surface of the sectorial plate is provided with teeth, and a toothed slot engaged with the teeth is provided at an outer circumferential side of the transmission disc, wherein the toothed slot forms the driving slot.

Furthermore, a transmission post is provided on the transmission disc, and an arc-shaped transmitting groove is provided coaxially on the driven shaft, wherein the transmission post is inserted into the arc-shaped transmitting groove, such that when the transmission disc drives the transmission post to move from a middle portion of the arc-shaped transmitting groove to an end portion of the arc-shaped transmitting groove, the claw is released out of the driving slot and the locking slot.

Furthermore, a plurality of the driving slots are arranged at uniform intervals in the outer circumferential side of the transmission disc, and a plurality of the locking slots are provided on the driven shaft, wherein a plurality of the claws are respectively snapped into the plurality of driving slots and the plurality of locking slots so as to lock the driven shaft from rotation.

Furthermore, the body further comprises a fixed sleeve fixed relative to the vehicle body, wherein the fixed sleeve is sleeved over the driven shaft, and the locking member is rotatably mounted on an end face of the fixed sleeve.

Furthermore, a limit groove is provided at one of an inner circumferential side of the fixed sleeve and an outer circumferential side of the driven shaft, and a limit boss inserted into the limit groove is provided at the other one of the inner circumferential side of the fixed sleeve and the outer circumferential side of the driven shaft, wherein the limit boss moves between two ends of the limit groove.

Furthermore, the body comprises a housing and a motor assembly disposed in the housing, wherein the driving shaft, the transmission disc, and the locking member are disposed in the housing, and the motor assembly actuates the driving shaft to rotate; wherein one end of the driven shaft is disposed in the housing, and the other end of the driven shaft extends out of the housing to connect with the hitch.

Furthermore, the body comprises a housing that covers outside the transmission disc and the locking member, wherein one end of the driven shaft is disposed in the housing, and the other end of the driven shaft extends out of the housing to connect with the hitch; wherein one end of the driving shaft is disposed in the housing, and the other end of the driving shaft extends out of the housing.

The present disclosure offers the following beneficial effects:
In the present disclosure, when the driving shaft actuates the transmission disc to idle to cause the locking member to unlock the driven shaft to rotate or lock the driven shaft from rotation, the transmission disc is in a rotating status while the driven shaft maintains a stationary status. To use the trailer hitch coupler, the transmission disc is first actuated by the driving shaft to idle, causing the locking member to unlock the driven shaft to rotate, thereby driving the driven shaft to rotate; then, the driving shaft continues rotating to actuate, via the transmission disc, the driven shaft to rotate, wherein rotation of the driven shaft may switch the hitch from the folded position to the unfolded position; next, the driving shaft actuates the transmission disc to idle reversely so as to drive the locking member to lock the driven shaft from rotation; when the driving shaft is actuating the transmission disc to idle reversely, the driven shaft maintains stationary to keep the hitch at the unfolded position, such that after the locking member locks the driven shaft from rotation, the hitch may be locked at the unfolded position, thereby preventing sway of the hitch when a trailer is hitched, which further enhances hitching performance. Likewise, the same unlocking and locking principles apply to switching the hitch from the unfolded position to the folded position, except for a different rotating direction. Therefore, the technical solutions of the present disclosure may also lock the hitch to the folded position to prevent sway of the hitch at that position, further enhancing hitching performance of the trailer hitch coupler.

Furthermore, when the claw is snapped into the driving slot and the locking slot, the claw locks the driven shaft from rotation; and when the transmission disc rotates to release the claw out of the driving slot and the locking slot, the claw unlocks the driven shaft to rotate. With such a configuration, when the transmission disc is idling, a sidewall of the driving slot is driven to push the claw to rotate out of the driving slot and the locking slot, such that the claw unlocks the driven shaft to rotate; when the transmission disc idles reversely, the claw is reset and snapped into the driving slot and the locking slot so as to lock the driven shaft from rotation, which prevents rotation of the driven shaft.

The claw is provided with a torsion spring for driving the claw to reset; and after the claw is reset, the claw is snapped into the driving slot and the locking slot. With such a configuration, resilience of the torsion spring enables the claw to rotate to be automatically reset, thereby locking the driven shaft from rotation. This configuration offers a simple structure and facilitates assembly.

The locking slot is an arc-shaped slot; the claw is a sectorial plate, wherein an arc-shaped surface of the sectorial plate matches the arc-shaped slot; the driving slot is a trapezoidal slot, wherein an opening of the trapezoidal slot is gradually enlarged radially outwardly; or, the arc-shaped surface of the sectorial plate is provided with teeth, and a toothed slot engaged with the teeth is provided at an outer circumferential side of the transmission disc, wherein the toothed slot forms the driving slot. With such a configuration, the transmission disc may smoothly actuate the claw to rotate to be released out of the locking slot; and in a locked state, this configuration further enhances the locking effect between the claw and the locking slot.

A transmission post is provided on the transmission disc, and an arc-shaped transmitting groove is coaxially provided on the driven shaft, wherein the transmission post is inserted into the arc-shaped transmitting groove, such that when the transmission disc drives the transmission post to move from a middle portion of the arc-shaped transmitting groove to an end portion of the arc-shaped transmitting groove, the claw is released out of the driving slot and the locking slot. With such a configuration, when the transmission disc is driving the transmission post to move from the middle portion of the arc-shaped transmitting groove to the end portion of the arc-shaped transmitting groove, idling of the transmission disc may be realized, at which point the driven shaft does not rotate; when the transmission post moves to the end portion of the arc-shaped transmitting groove, the claw unlocks the driven shaft to rotate, at which point the driven shaft may rotate, whereby to continuously drive the transmission disc to rotate, enabling the transmission post to drive the driven shaft to rotate, further realizing switching of the hitch between the folded position and the unfolded position; when the transmission post is moving from the end portion of the arc-shaped transmitting groove to the middle portion of the arc-shaped transmitting groove, the transmission disc is idling, at which point the driven shaft does not rotate; when the transmission post moves to the middle portion of the arc-shaped transmitting groove, the claw locks the driven shaft from rotation.

A plurality of driving slots are arranged at uniform intervals in an outer circumferential side of the transmission disc, and a plurality of locking slots are provided on the driven shaft, wherein a plurality of claws are respectively snapped into the plurality of driving slots and the plurality of locking slots so as to lock the driven shaft from rotation. By arranging the plurality of claws in one-to-one locking fit with the plurality of locking slots, the effect of locking the driven shaft may be enhanced, thereby further preventing the hitch from sway caused by the rotation of the driven shaft.

The body further comprises a fixed sleeve fixed relative to the vehicle body, wherein the fixed sleeve is sleeved over the driven shaft, and the locking member is rotatably mounted on an end face of the fixed sleeve. With such a configuration, the driven shaft may be radially positioned via the fixed sleeve so as to ensure coaxiality between the driven shaft and the transmission disc; besides, the fixed sleeve provides a carrier for mounting the locking member, thereby simplifying the body structure.

A limit groove is provided at one of an inner circumferential side of the fixed sleeve and an outer circumferential side of the driven shaft, and a limit boss inserted into the limit groove is provided at the other of the inner circumferential side of the fixed sleeve and the outer circumferential side of the driven shaft, wherein the limit boss moves between two ends of the limit groove. Such a configuration may limit the rotating angle of the driven shaft so as to define an initial position and an end position of the driven shaft, which further ensures locking effect of the hitch at the folded position and the unfolded position.

The body comprises a housing and a motor assembly disposed in the housing, wherein the driving shaft, the transmission disc, and the locking member are disposed in the housing; the motor assembly actuates the driving shaft to rotate; one end of the driven shaft is disposed in the housing, and the other end of the driven shaft extends out of the housing to connect with the hitch. With the motor assembly actuating the driving shaft to rotate, user experience may be enhanced.

Alternatively, the body comprises a housing that covers outside the transmission disc and the locking member, wherein one end of the driven shaft is disposed in the housing, the other end of the driven shaft extends out of the housing to connect with the hitch; and wherein one end of the driving shaft is disposed in the housing, and the other end of the driving shaft extends out of the housing. With such a configuration, the driving shaft may also be actuated to rotate when a user rotates the end of the driving shaft extending out of the housing by a wrench or by bare hands, which eliminates a need for a motor assembly, thereby reducing manufacturing cost of the product; furthermore, without the motor assembly, failure of the product due to electric fault may also be avoided.

These characteristics and advantages of the present disclosure will be disclosed in detail in the detailed description and accompanying drawings below.

Hereinafter, the present disclosure will be described in further detail with reference to the accompanying drawings:
<FIG> is an exploded structural view of a trailer hitch coupler according to a first embodiment of the present disclosure;.

Hereinafter, the present disclosure will be described in further detail with reference to the accompanying drawings:.

hitch; <NUM>. driving shaft; <NUM>. locking member; <NUM>. torsion spring; <NUM>. tooth; <NUM>. transmission disc; <NUM>. driving slot; <NUM>. transmission post; <NUM>. driven shaft; <NUM>. locking slot; <NUM>. arc-shaped transmitting groove; <NUM>. limit boss; <NUM>. connecting plate; <NUM>: housing; <NUM>: fixed sleeve; <NUM>: pin; <NUM>: limit groove; <NUM>: cover plate; <NUM>. motor assembly.

The present disclosure provides a trailer hitch coupler, comprising a body secured to a vehicle body and a hitch, wherein the body comprises a driving shaft, a locking member, a transmission disc, and a driven shaft, wherein the driven shaft is connected to and rotates synchronously with the hitch, and the driving shaft actuates the transmission disc to idle such that the locking member unlocks the driven shaft to rotate or locks the driven shaft from rotation; wherein when the locking member unlocks the driven shaft to rotate, the driving shaft actuates, via the transmission disc, the driven shaft to rotate such that the hitch switches between a folded position and a unfolded position; when the hitch is at the folded position or at the unfolded position, the locking member locks the driven shaft from rotation.

In the present disclosure, when the driving shaft actuates the transmission disc to idle such that the locking member unlocks the driven shaft to rotate or locks the driven shaft from rotation, the transmission disc is in a rotating status while the driven shaft maintains a stationary status. To use the trailer hitch coupler, the driving shaft first actuates the transmission disc to idle such that the locking member unlocks the driven shaft to rotate, thereby driving the driven shaft to rotate; then, the driving shaft continues rotating to actuate, via the transmission disc, the driven shaft to rotate, wherein rotation of the driven shaft may switch the hitch from the folded position to the unfolded position; next, the driving shaft actuates the transmission disc to idle reversely so as to drive the locking member to lock the driven shaft from rotation, wherein when the driving shaft is actuating the transmission disc to idle reversely, the driven shaft maintains stationary to keep the hitch at the unfolded position, such that after the locking member locks the driven shaft from rotation, the hitch may be locked at the unfolded position, thereby preventing the hitch from sway when a trailer is hitched, thereby enhancing hitching performance. Likewise, the same unlocking and locking principles apply to switching the hitch from the unfolded position to the folded position, except for a different rotating direction. Therefore, the technical solutions of the present disclosure may also lock the hitch to the folded position to prevent sway of the hitch at that position, further enhancing hitching performance of the trailer hitch coupler.

Hereinafter, the technical solutions of the present disclosure will be explained and illustrated through embodiments with reference to the accompanying drawings. However, the embodiments are only some embodiments of the present disclosure, not all of them.

As illustrated in <FIG>, a trailer hitch coupler in the embodiment comprises: a body secured to an anti-collision bumper of a vehicle body and a hitch <NUM>, wherein the body comprises a driving shaft <NUM>, a locking member <NUM>, a transmission disc <NUM>, and a driven shaft <NUM>, wherein the driven shaft <NUM> is connected to and rotates synchronously with the hitch <NUM>, and the driving shaft <NUM> actuates the transmission disc <NUM> to idle such that the locking member <NUM> locks the driven shaft <NUM> from rotation or unlocks the driven shaft <NUM> to rotate; while when the locking member <NUM> unlocks the driven shaft <NUM> to rotate, the driving shaft <NUM> actuates, via the transmission disc <NUM>, the driven shaft <NUM> to rotate such that the hitch <NUM> switches between the folded position and the unfolded position; when the hitch <NUM> is at the folded position or at the unfolded position, the locking member <NUM> locks the driven shaft <NUM> from rotation.

In this embodiment, when the driving shaft <NUM> actuates the transmission disc <NUM> to idle such that the locking member <NUM> locks the driven shaft <NUM> from rotation or unlocks the driven shaft <NUM> to rotate, the transmission disc <NUM> is in a rotating status while the driven shaft <NUM> maintains a stationary status. To use the trailer hitch coupler, the driving shaft <NUM> first actuates the transmission disc <NUM> to idle such that the locking member <NUM> unlocks the driven shaft <NUM> to rotate, thereby moving the driven shaft <NUM> to rotate; then, the driving shaft <NUM> continues rotating to actuate, via the transmission disc <NUM>, the driven shaft <NUM> to rotate, wherein rotation of the driven shaft <NUM> may switch the hitch <NUM> from the folded position to the unfolded position; next, the driving shaft <NUM> actuates the transmission disc <NUM> to idle reversely so as to drive the locking member <NUM> to lock the driven shaft <NUM> from rotation, wherein when the driving shaft <NUM> is actuating the transmission disc <NUM> to idle reversely, the driven shaft <NUM> maintains stationary to keep the hitch <NUM> at the unfolded position, such that after the locking member <NUM> locks the driven shaft <NUM> from rotation, the hitch <NUM> may be locked at the unfolded position, thereby preventing the hitch <NUM> from sway when a trailer is hitched, further enhancing hitching performance. Likewise, the same unlocking and locking principles apply to switching the hitch <NUM> from the unfolded position to the folded position, except for a different rotating direction of the driving shaft <NUM>. Therefore, the technical solutions of the present disclosure may also lock the hitch <NUM> to the folded position to prevent sway of the hitch <NUM> at that position, further enhancing hitching performance of the trailer hitch coupler.

Specifically, the body in this embodiment further comprises a connecting plate <NUM> secured to the anti-collision beam, and a housing <NUM> snap-fitted to one side of the connecting plate <NUM>; wherein one end of the fixed sleeve <NUM> is disposed in the housing <NUM> and the other end of the fixed sleeve <NUM> passes through the connecting plate <NUM>, both of the fixed sleeve <NUM> and the housing <NUM> being secured to the connecting plate <NUM> via bolts; wherein the fixed sleeve <NUM> is sleeved over the driven shaft <NUM> so as to radially position the driven shaft <NUM>, which ensures coaxiality between the driven shaft <NUM> and the transmission disc <NUM>; wherein one end of the driven shaft <NUM> is disposed in the housing <NUM>, and the other end thereof extends out of the fixed sleeve <NUM> to connect with the hitch <NUM>, wherein the portion of the driven shaft <NUM> connected with the hitch <NUM> is a non-circular surface fitted with a non-circular hole in the hitch <NUM> to thereby realize that the driven shaft <NUM> drives the hitch <NUM> to rotate synchronously; a cover plate <NUM> is further securely provided in the housing <NUM>, wherein the transmission disc <NUM> is movably connected onto the cover plate <NUM> via a plane bearing; the driving shaft <NUM>, after passing through the cover plate <NUM> and the plane bearing, is in transmission connection with the transmission disc <NUM>, i.e., the portion of the driving shaft <NUM> fitted with the non-circular hole in the transmission disc <NUM> is a non-circular plane. Such a configuration enables the driving shaft <NUM> to actuate the transmission disc <NUM> to rotate synchronously.

In the embodiment illustrated in <FIG>, the locking member <NUM> is a rotatably mounted claw, wherein the claw is a sectorial plate. A pin <NUM> is provided on an end face of the fixed sleeve <NUM> located in the housing <NUM>, and the claw is rotatably mounted on the pin <NUM>. A torsion spring <NUM> is sleeved over the claw, one end of the torsion spring <NUM> being secured on the fixed sleeve <NUM> or the cover plate <NUM>, the other end of the torsion spring <NUM> being secured to a bump on the claw, such that the claw may be driven to reset by resilience of the torsion spring <NUM>. In this embodiment, a driving slot <NUM> is further provided at the outer circumferential side of the transmission disc <NUM>, the driving slot <NUM> being a trapezoidal slot, wherein the opening of the trapezoidal slot is gradually enlarged radially outwardly. One end of the driven shaft <NUM> proximal to the transmission disc <NUM> extends radially outwardly to form a circular ring. A locking slot <NUM> is provided at the outer circumferential side of the circular ring, the locking slot <NUM> being an arc-shaped slot, wherein the arc-shaped slot matches the arc-shaped surface of the sectorial plate. When the driving shaft <NUM> actuates the transmission disc <NUM> to idle, a sidewall of the driving slot <NUM> is driven to push the claw to rotate out of the driving slot <NUM> and the locking slot <NUM>, such that the claw unlocks the driven shaft <NUM> to rotate. When the driving shaft <NUM> actuates the transmission disc <NUM> to idle reversely, the claw is automatically reset and snapped into the driving slot <NUM> and the locking slot <NUM> under resilience of the torsion spring <NUM>, thereby locking the driven shaft <NUM> from rotation, which prevents the driven shaft <NUM> from rotation. Additionally, when the driven shaft <NUM> is locked, no force is transmitted between the claw and the driving slot <NUM> such that in a locked status, the driven shaft <NUM> is disengaged from the transmission disc <NUM>, further avoiding the driving shaft <NUM> from being stressed all the time, which further extends service life of the driving shaft <NUM>. Particularly when the driving shaft <NUM> actuates a rotation via a motor assembly, this configuration may also extend service life of the motor assembly. Furthermore, in this embodiment, by configuring the driving slot <NUM> as a trapezoidal slot, the transmission disc <NUM> may smoothly actuate the claw to rotate to be released out of the locking slot <NUM>; while by configuring the locking slot <NUM> to match the arc-shaped surface of the sectorial plate, the effect of locking between the claw and the locking slot <NUM> may be enhanced in the locked status.

It is understood that in alternative embodiments of the present disclosure, an annular mounting plate surrounding the outside of the driven shaft is provided at the inner sidewall of the housing, wherein the locking member is rotatably mounted on the mounting plate.

To realize idling of the transmission disc <NUM> relative to the driven shaft <NUM>, a transmission post <NUM> extending axially is provided on a disc face of the transmission disc <NUM>, and an arc-shaped transmitting groove <NUM> is provided coaxially on the driven shaft <NUM>, the transmission post <NUM> being inserted in the arc-shaped transmitting groove <NUM>. In a status where the claw locks the driven shaft <NUM>, the transmission post <NUM> is disposed at the middle portion of the arc-shaped transmitting groove <NUM>. When the driving shaft <NUM> actuates the transmission disc <NUM> to rotate such that the transmission disc <NUM> drives the transmission post <NUM> to move from the middle portion of the arc-shaped transmitting groove <NUM> to the end portion of the arc-shaped transmitting groove <NUM>, the claw is released out of the driving slot <NUM> and the locking slot <NUM>, thereby unlocking the driven shaft <NUM> to rotate; when the transmission post <NUM> is moving from the middle portion of the arc-shaped transmitting groove <NUM> to the end portion of the arc-shaped transmitting groove <NUM>, since the transmission post <NUM> is sliding in the arc-shaped transmitting groove <NUM>, which does not apply a torsion to the driven shaft <NUM>, the transmission disc <NUM> rotates but the driven shaft <NUM> does not rotate, thereby realizing idling of the transmission disc <NUM>. After the claw unlocks the driven shaft <NUM> to rotate to continuously actuate the transmission disc <NUM> to rotate, the transmission post <NUM> pushes a slot wall of the arc-shaped transmitting groove <NUM> to actuate the driven shaft <NUM> to rotate, thereby realizing switching of the hitch <NUM> between the folded position and the unfolded position, and then the driving shaft <NUM> actuates the transmission disc <NUM> to rotate reversely such that when the transmission post <NUM> is moving from the end portion of the arc-shaped transmitting groove to the middle portion of the arc-shaped transmitting groove, the driven shaft <NUM> does not rotate so as to maintain the hitch <NUM> at the folded position or at the unfolded position; when the transmission post <NUM> moves to the middle portion of the arc-shaped transmitting groove <NUM>, the claw is reset and snapped into the driving slot <NUM> and the locking slot <NUM> to thereby lock the driven shaft <NUM> from rotation.

To actuate the driven shaft <NUM> to rotate smoothly, in this embodiment, two transmission posts <NUM> are symmetrically provided about the center of the disc face of the transmission disc <NUM>, and correspondingly, two arc-shaped transmitting grooves <NUM> are provided on the driven shaft <NUM>. Such a configuration not only ensures smooth rotation of the driven shaft <NUM>, but also ensures the size of the claw, thereby ensuring the effect of locking the driven shaft <NUM>.

To enhance the effect of locking the driven shaft <NUM> and further prevent sway of the hitch <NUM> caused by the rotation of the driven shaft <NUM>, in this embodiment, a plurality of driving slots <NUM> are arranged at uniform intervals at the outer circumferential side of the transmission disc <NUM>; and a plurality of locking slots <NUM> are provided on the driven shaft <NUM>, wherein the plurality of claws are inserted into the plurality of driving slots <NUM> and the plurality of locking slots <NUM>, respectively, so as to lock the driven shaft <NUM> from rotation, whereby to enhance the effect of locking the driven shaft <NUM> and further prevent sway of the hitch <NUM> caused by rotation of the driven shaft <NUM>. In this embodiment, the number of the claws, the number of the driving slots <NUM>, and the number of the locking slots <NUM> are preferably identical, which are all <NUM>. With such a configuration, the effect of locking the driven shaft <NUM> is enhanced by one-to-one locking fit between the <NUM> claws and the <NUM> locking slots <NUM>.

It is understood that in alternative embodiments of the present disclosure, the number of the driving slots and the number of the locking slots may be greater than that of the claws, wherein the claws are snapped into some of the locking slots and the driving slots. For example, if the number of the claws is <NUM>, while the numbers of the driving slots and the locking slots are both <NUM>, then the <NUM> claws are snapped into three locking slots and three driving slots thereof. Such a configuration may also enhance the effect of locking the driven shaft.

It is understood that in alternative embodiments of the present disclosure, the arc-shaped transmitting groove may also be provided on the disc face of the transmission disc, while the transmission post is provided on the driven shaft, the transmission post being inserted in the arc-shaped transmitting groove. As such, when the locking member locks the driven shaft from rotation, the transmission post is disposed at the middle portion of the arc-shaped transmitting groove; while when the locking member unlocks the driven shaft to rotate, the transmission post abuts the end portion of the arc-shaped transmitting groove.

To better understand the technical solution of the present disclosure, the operating principle of the trailer hitch coupler in this embodiment is explained below:.

As illustrated in <FIG>, the locking member <NUM> locks the driven shaft <NUM> from rotation, at which point the hitch <NUM> is at the folded position, and the driving shaft <NUM> actuates the transmission disc <NUM> to idle clockwise. When the transmission post <NUM> is moving from the middle portion of the arc-shaped transmitting groove <NUM> to the right end portion of the arc-shaped transmitting groove <NUM>, a slot wall of the driving slot <NUM> is driven to push the claw to rotate towards the outside of the locking slot <NUM>; after the transmission post <NUM> moves to the right end portion of the arc-shaped transmitting groove <NUM>, the claw is released out of the driving slot <NUM> and the locking slot <NUM> (as illustrated in <FIG>), thereby unlocking the driving shaft <NUM> to rotate; the driving shaft <NUM> continuously actuates the transmission disc <NUM> to rotate clockwise, at which point the driven shaft <NUM>, actuated by the transmission post <NUM>, drives the hitch <NUM> to rotate synchronously till the unfolded position; afterwards, the driving shaft <NUM> actuates the transmission disc <NUM> to idle reversely (i.e., counterclockwise); when the transmission post <NUM> is moving from the right end of the arc-shaped transmitting groove <NUM> to the middle portion of the arc-shaped transmitting groove <NUM>, the driven shaft <NUM> does not rotate to maintain the hitch <NUM> at the unfolded position; after the transmission post <NUM> moves to the middle portion of the arc-shaped transmitting groove <NUM>, the driving slot <NUM> corresponds to the locking slot <NUM>, such that the claw is reset and snapped into the driving slot <NUM> and the locking slot <NUM> under resilience of the torsion spring <NUM>, thereby locking the driven shaft <NUM> from rotation, i.e., preventing the driven shaft <NUM> from rotation, which further prevents sway of the hitch <NUM> at the unfolded position.

Likewise, when it is needed to switch the hitch <NUM> from the unfolded position to the folded position, the driving shaft <NUM> actuates the transmission disc <NUM> to idle counterclockwise; when the transmission post <NUM> is moving from the middle portion of the arc-shaped transmitting groove <NUM> to the left end portion of the arc-shaped transmitting groove <NUM>, the slot wall of the driving slot <NUM> is driven to push the claw to rotate towards the outside of the locking slot <NUM>; after the transmission post <NUM> moves to the end portion of the arc-shaped transmitting groove <NUM>, the claw is released out of the driving slot <NUM> and the locking slot <NUM>, thereby unlocking the driving shaft <NUM> to rotate; the driving shaft <NUM> continuously actuates the transmission disc <NUM> to rotate counterclockwise, at which point the driven shaft <NUM>, actuated by the transmission post <NUM>, drives the hitch <NUM> to rotate synchronously till the folded position; afterwards, the driving shaft <NUM> actuates the transmission disc <NUM> to idle reversely (i.e., clockwise); when the transmission post <NUM> is moving from the left end of the arc-shaped transmitting groove <NUM> to the middle portion of the arc-shaped transmitting groove <NUM>, the driven shaft <NUM> does not rotate so as to maintain the hitch <NUM> at the folded position; after the transmission post <NUM> moves to the middle portion of the arc-shaped transmitting groove <NUM>, the driving slot <NUM> corresponds to the locking slot <NUM>, such that the claw is reset and snapped into the driving slot <NUM> and the locking slot <NUM> under resilience of the torsion spring <NUM>, thereby locking the driven shaft <NUM> from rotation, i.e., preventing the driven shaft <NUM> from rotation, which further prevents sway of the hitch <NUM> at the folded position.

To ensure an exact one-to-one correspondence between the driving slot <NUM> and the locking slot <NUM> after reverse idling of the transmission disc <NUM> so as to snap the claw into the driving slot <NUM> and the locking slot <NUM>, it is needed to limit a desired rotating angle of the driven shaft <NUM> when the hitch <NUM> switches between the folded position and the unfolded position. To ensure accuracy of limiting the rotating angle, as illustrated in the embodiment shown in <FIG>, an arc-shaped limit groove <NUM> is provided at the inner circumferential side of the fixed sleeve <NUM>, and a limit boss <NUM> is provided at the outer circumferential side of the driven shaft <NUM> fitted with the fixed sleeve <NUM>, wherein the limit boss <NUM> moves between two ends of the limit groove <NUM>, thereby limiting the rotating angle of the driven shaft <NUM> by limiting the rotating angle of the limit boss <NUM>, which defines the initial position and the end position of the driven shaft <NUM>, further ensuring the effect of locking the hitch <NUM> at the folded position and the unfolded position.

It is understood that in alternative embodiments of the present disclosure, the arc-shaped limit groove may also be provided at the outer circumferential side of the driven shaft, while the limit boss projects from the inner circumferential side of the fixed sleeve.

Finally, to enhance user experience of the product, a motor assembly <NUM> is further provided in the housing <NUM> in this embodiment, wherein the driving shaft <NUM> is disposed in the housing <NUM> and connected with an output bushing of the motor assembly <NUM>, wherein the motor assembly <NUM> actuates the driving shaft <NUM> to rotate to switch the hitch <NUM> between the folded position and the unfolded position. The whole process does not need the user to manually actuate the driving shaft <NUM> to rotate, thereby enhancing use experience of the product.

As illustrated in <FIG>, the second embodiment differs from the first embodiment in that teeth <NUM> are provided on an arc-shaped surface of the claw, and a toothed slot engaged with the teeth is provided at the outer circumferential side of the transmission disc <NUM>, the transmission disc <NUM> being preferably a gearwheel, and the toothed slot forming the driving slot <NUM>. Such a configuration may also realize pushing the claw out of the locking slot <NUM> by a slot wall of the driving slot <NUM>.

As illustrated in <FIG>, the third embodiment differs from the first embodiment and the second embodiment in that the fixed sleeve <NUM> and the connecting plate <NUM> are integrally machined to form a connecting and fixing plate, wherein the connecting and fixing plate is secured to an anti-collision beam.

Claim 1:
A trailer hitch coupler comprising a body secured to a vehicle body and a hitch (<NUM>), said body comprising a driving shaft (<NUM>), a locking member (<NUM>), a transmission disc (<NUM>), and a driven shaft (<NUM>) which is connected to and rotates synchronously with the hitch (<NUM>), said driving shaft (<NUM>) actuating the transmission disc (<NUM>) to idle such that the locking member (<NUM>) unlocks the driven shaft (<NUM>) to rotate or locks the driven shaft (<NUM>) from rotation, wherein, when the locking member (<NUM>) unlocks the driven shaft (<NUM>) to rotate, the driving shaft (<NUM>) actuates, via the transmission disc (<NUM>), the driven shaft (<NUM>) to rotate such that the hitch (<NUM>) switches between a folded position and an unfolded position, and wherein, when the hitch (<NUM>) is in the folded position or in the unfolded position, the locking member (<NUM>) locks the driven shaft (<NUM>) from rotation, characterized in that the locking member (<NUM>) is a rotatably mounted claw, a driving slot (<NUM>) is provided on the transmission disc (<NUM>), and a locking slot (<NUM>) is provided on the driven shaft (<NUM>), such that when the claw is snapped into the driving slot (<NUM>) and the locking slot (<NUM>), the claw locks the driven shaft (<NUM>) from rotation, and when the transmission disc (<NUM>) rotates to release the claw out of the driving slot (<NUM>) and the locking slot (<NUM>), the claw unlocks the driven shaft (<NUM>) to rotate.