Patent Description:
Loading ramps are generally designed to receive a semitrailer with the rear end first. Hence, the driver of the semitrailer will have to reverse the semitrailer towards the loading ramp. Optical devices are often present at the loading ramp to alert the driver when he is in place in front of the loading ramp. However, for some reason, the driver does not pay attention to the warning signal and collides the semitrailer with the loading ramp. Since, many types of semitrailers arrive at a loading ramp each day, it is difficult to position a physical stop in front of the rear wheels of the semitrailer. The distance between the rear wheels and the rear end of the semitrailer simply varies too much from one type of semitrailer to another.

<CIT> discloses a system for preventing semitrailer collisions with a loading ramp. The system comprises a sensor and guide block. The sensor is configured for sensing when the rear end of a semitrailer is approaching a loading ramp. The guide block is adapted to be positioned on the ground. The guide block comprises wheel blocking means configured for supporting the tread of a rear tire of the semitrailer. The wheel blocking means is configured to move from a forwarded position relative to the loading ramp to a retracted position relative to the loading ramp as the semitrailer is reversing towards said loading ramp. The sensor is configured to send a blocking signal to the guide block when the distance between the rear end of the semitrailer and the loading ramp is below a preset threshold, thereby blocking the movement of the wheel blocking means. There is a risk, that this type of wheel blocking means may interfere with the rear tire's rain flap, thereby damaging it or even tearing it off. <CIT> discloses a system for preventing semitrailer collisions with a loading ramp according to the preamble of claim <NUM>.

It is an object of the present invention to overcome the above-mentioned problems.

poet relates to a system for preventing semitrailer collisions with a loading ramp comprising:.

The description further relates to a system for preventing semitrailer collisions with a loading ramp comprising:.

In principle, the first wheel blocking means is initially positioned at an extended position relative to the loading ramp, where the rear end of the semitrailer is at no risk of colliding with the loading ramp. The semitrailer is reversed until its rear wheel at the driver side reaches the first wheel blocking means. The rain flap isolation device secures that the rain flap of the rear wheel will not get stuck between the rear wheel and the sled, thereby removing the risk of damage.

The driver then continues to reverse the semitrailer as the first wheel blocking means continuously supports the rear wheel in a retractive movement, relative to the loading ramp, until the sensor unit sends a blocking signal to the guide block when the distance between the rear end of the semitrailer and the loading ramp is below a preset threshold. In response to the blocking signal, the first wheel blocking means locks its position, and the driver will feel that the semitrailer brakes. He then knows that the semitrailer is in position. Thereby, the semitrailer will never risk colliding with the loading ramp, and the solution is independent on the type of semitrailer.

The sensor unit's sensor is configured for sensing when the rear end of a semitrailer is approaching a loading ramp and is preferably a distance sensor or a laser beam sensor. The term "distance sensor" for the purposes of this invention can be one or more of an infrared sensor, a triangulation sensor, an ultrasonic sensor, or the like, or combinations thereof.

In one or more embodiments, the first wheel blocking means is configured such that the work of the rear wheel of the semitrailer on the wheel blocking means makes the first wheel blocking means move from a forwarded position relative to the loading ramp to a retracted position relative to the loading ramp. Hence, it is only the force of the reversing semitrailer that moves the first wheel blocking means from a forwarded position to a retracted position. Such a specific configuration could e.g. be that the first wheel blocking means is connected to a locking means comprising a toothed rack, and a locking pin; and wherein the locking pin is configured to engage with the toothed rack upon receipt, either directly or indirectly, of a blocking signal from said sensor unit. The toothed rack is preferably positioned along the length of the guide block. The locking pin will then be in a retracted position until the blocking signal is received. Furthermore, the guide block could comprise an elongate guide rail extending along the length of said guide block; wherein the sled comprises:.

In one or more embodiments, the sled comprises:.

In one or more embodiments, the activation means is a lever pivotably connected to the sled, preferably to the distal end or to the middle end. When the lever is pivoted when the rear tire rests on its free end, the other end of the lever raises the plate or rod. Preferably, the lever has a first end connected to the plate or rod, and a second free end.

wherein the second free end is bent downwards, and adapted for pivoting between a first position above the middle segment and a second position within the first hole or cavity in the middle segment. The shape and position of the free end secures that a tire moving over the lever will not risk being penetrated.

In one or more embodiments, the system further comprises a guide rail adapted for supporting the sled; wherein the sled further comprises a second wheel blocking means; said second wheel blocking means adapted to slidably or rollably engage with said guide rail; wherein the guide rail is configured with one or more elevations along its path; and wherein when the second wheel blocking means engages with said elevations it moves from a retracted position to an elevated position. The wheel support is preferably integrated into the distal end of the sled.

In one or more embodiments, the second wheel blocking means comprises a flap adapted to move from a retracted position to an elevated position, and one or more wheels adapted to rollably engage with the guide rail.

In one or more embodiments, the second wheel blocking means further comprises a support wheel attached to and extending laterally to the flap, and a support and guide rail configured to support and guide said support wheel as the sled is moving between the forwarded position relative to said loading ramp and the retracted position relative to said loading ramp. This configuration strengthens the second wheel blocking means, making it more resistant to the forces exerted on it by the semitrailer.

In one or more embodiments, the system further comprises a locking system adapted to retain and release the sled; wherein the locking system comprises a locking pin, and an anchor positioned below said sled; wherein the locking pin is pivotably attached to the bottom side of said sled; wherein the locking pin comprises a first end adapted for moving from an extended position on the top side of the sled through a hole in said sled to a retracted position within said hole; and a second end adapted for moving from an extended position on the bottom side of said sled to a retracted position also on the bottom side of said sled; wherein the second end of said locking pin is adapted to be engaged with said anchor in its retracted position. This configuration allows the rear tire to get into position before the sled starts to move.

In one or more embodiments, the sled is connected to a locking means comprising a toothed rack, and a locking pin; and wherein the locking pin is configured to engage with the toothed rack upon receipt, either directly or indirectly, of a blocking signal from said sensor unit.

The blocking signal may be transmitted by wires or wireless.

In one or more embodiments, the sled is connected to a locking pin housing adapted to move the locking pin above and along the toothed rack.

In one or more embodiments, the sensor unit, subsequent to a blocking signal, is configured to send a reactivation signal to the guide block when the distance between the rear end of the semitrailer and the loading ramp exceeds a preset threshold, thereby reactivating the guide block to move from a retracted position relative to the loading ramp to a forwarded position relative to the loading ramp. In one or more embodiments, the guide block comprises a sensor unit configured for sensing when the semitrailer has disengaged therefrom; and wherein the sensor unit is configured to activate the guide block to move from a retracted position relative to the loading ramp to a forwarded position relative to the loading ramp.

This description relates to the use of a system according to the present invention for preventing semitrailer collisions with a loading ramp.

Another aspect relates to the use of a system according to the present invention for guiding a semitrailer towards and/or away from a loading ramp.

It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

Referring to <FIG>, the general scheme of the invention is shown in perspective view. <FIG> shows a system for preventing semitrailer collisions with a loading ramp <NUM>. The system comprises a sensor unit <NUM> comprising a sensor, a guide block <NUM>, and a rain flap <NUM> isolation device (<NUM>, <FIG>). The sensor unit <NUM> is configured for sensing when the rear end of a semitrailer <NUM> is approaching a loading ramp <NUM>. The guide block <NUM> is adapted to be positioned on the ground and is here shown positioned laterally to the opening of the loading ramp <NUM>. In <FIG>, the guide block <NUM> is shown comprising a first wheel blocking means configured as a sled <NUM> adapted for supporting the tread of a rear tire <NUM> of a semitrailer <NUM>. The sled <NUM> is configured to move, preferably only by the aid of the semitrailer, from a forwarded position relative to said loading ramp <NUM> to a retracted position relative to said loading ramp <NUM> when being pushed by said rear tire <NUM> as said semitrailer <NUM> is reversing towards said loading ramp <NUM>. To ease its movement across a surface, the sled <NUM> is provided with wheels <NUM> (<FIG>). The sensor unit <NUM> is configured to send a blocking signal to the guide block <NUM> when the distance between the rear end of the semitrailer <NUM> and the loading ramp <NUM> is below a preset threshold, thereby blocking the movement of the sled <NUM>.

<FIG> show a specific example of a rain flap isolation device in accordance with various embodiments of the invention. The rain flap isolation device secures that the rain flap <NUM> of the rear wheel <NUM> will not get stuck between the rear wheel <NUM> and the sled <NUM>, thereby removing the risk of damage. In general, the rain flap isolation device comprises i) a first part integrated with the sled <NUM> and comprising a plate <NUM> adapted for moving between a retracted position and an extended position; and ii) an activation means <NUM> configured for activating the plate <NUM> to move from the retracted position to the extended position. The plate <NUM> moves upwards relative to the sled <NUM> when in the extended position. <FIG> and <FIG> show the sled in a forwarded position relative to said loading ramp <NUM>, where the plate <NUM> is in a retracted position as the activation means <NUM> has not yet been activated by the rear tire of a semitrailer. <FIG> and <FIG> show the sled in a retracted position relative to said loading ramp <NUM>, where the plate <NUM> is in a forwarded position as the activation means <NUM> has been activated by the rear tire (not shown) of a semitrailer.

To block the rear wheel from moving in either direction, the sled <NUM> further comprises a second wheel blocking means <NUM>. The system is provided with a guide rail <NUM> partly adapted for supporting the sled <NUM> and partly for supporting the second wheel blocking means <NUM>. In <FIG> and <FIG>, the second wheel blocking means <NUM> is shown in a retracted position, while it is shown in an elevated position in <FIG> and <FIG>.

To strengthen the second wheel blocking means <NUM>, making it more resistant to the forces exerted on it by the semitrailer, the second wheel blocking means <NUM> is adapted to rollably engage with the guide rail <NUM> by the aid of wheels <NUM> (<FIG>). The guide rail <NUM> is here shown configured with two parallel elevations <NUM> supporting the wheels <NUM>. When the second wheel blocking means <NUM> engages with said elevations <NUM>, the wheels <NUM> forces its flap <NUM> to move from a retracted position to an elevated position.

To even further strengthen the second wheel blocking means <NUM>, it is provided with a support wheel <NUM> attached to and extending laterally to the flap <NUM>, and a support and guide rail <NUM> configured to support and guide the support wheel <NUM> as the sled <NUM> is moving between the forwarded position relative to the loading ramp <NUM> and the retracted position relative to the loading ramp <NUM>.

To secure the rear tire to get into position before the sled <NUM> starts to move, the system further comprises a locking system adapted to retain and release the sled <NUM> (<FIG> and <FIG>). The locking system comprises a locking pin, and an anchor <NUM> positioned below the sled <NUM>. The locking pin is pivotably attached to the bottom side of said sled <NUM>, and comprises a first end <NUM> adapted for moving from an extended position on the top side of the sled <NUM> through a hole in said sled <NUM> to a retracted position within said hole; and a second end <NUM> adapted for moving from an extended position on the bottom side of said sled <NUM> to a retracted position also on the bottom side of said sled. The second end <NUM> of the locking pin is adapted to be engaged with the anchor <NUM> in its retracted position (not shown). To ease its movement across a surface, the sled <NUM> is provided with wheels <NUM>.

<FIG> shows a guide block <NUM> in accordance with various embodiments of the invention, where the sled <NUM> (a part of it may be seen) is connected to a locking means comprising a toothed rack <NUM>, and two locking pins <NUM>. The two locking pins <NUM> are attached to the sled <NUM>, and the toothed rack <NUM> is shown secured to an elongate guide rail <NUM>. The locking pins <NUM> are configured to engage with or disengage from the toothed rack <NUM> upon receipt, either directly or indirectly, of a blocking signal from a sensor unit (not shown but could be sensor unit <NUM> or <NUM> as seen in <FIG>). The guide block is shown comprising an elongate guide rail <NUM> extending along the length of the guide block. The sled <NUM> is slidably attached to said guide rail <NUM>. The guide rail <NUM> is here shown as a steel beam, a Hollow Steel Section (HSS) beam, providing sufficient strength to the guide block.

Claim 1:
A system for preventing semitrailer collisions with a loading ramp (<NUM>) comprising:
- a sensor unit (<NUM>) comprising a sensor and configured for sensing when the rear end of a semitrailer (<NUM>) is approaching a loading ramp (<NUM>);
- a guide block (<NUM>) adapted to be positioned on the ground, laterally and/or medially to the opening of a loading ramp (<NUM>); wherein the guide block (<NUM>) comprises a first wheel blocking means configured as a sled (<NUM>) adapted for supporting the tread of a rear tire (<NUM>) of said semitrailer (<NUM>), and configured to move, preferably passively, from a forwarded position relative to said loading ramp (<NUM>) to a retracted position relative to said loading ramp (<NUM>) when being pushed by said rear tire (<NUM>) as said semitrailer (<NUM>) is reversing towards said loading ramp (<NUM>); wherein said sensor unit (<NUM>) is configured to send a blocking signal to said guide block (<NUM>) when the distance between said rear end of said semitrailer (<NUM>) and said loading ramp (<NUM>) is below a preset threshold, wherein said wheel blocking means locks its position in response to said blocking signal, thereby blocking the movement of said sled (<NUM>); wherein the system further comprises:
- a rain flap (<NUM>) isolation device adapted for preventing said rear tire (<NUM>) and its rain flap (<NUM>) from touching each other while said rear tire (<NUM>) is positioned within said sled (<NUM>) during its movement from a forwarded position relative to said loading ramp (<NUM>) to a retracted position relative to said loading ramp (<NUM>) when being pushed by said rear tire (<NUM>) as said semitrailer (<NUM>) is reversing towards said loading ramp (<NUM>); and said system being characterized in that said rain flap (<NUM>) isolation device comprises:
i) a first part integrated into or connected to the sled (<NUM>) and comprising a plate or rod (<NUM>) adapted for moving between a retracted position and an extended position; and
ii) an activation means (<NUM>) configured for activating the plate or rod (<NUM>) to move from the retracted position to the extended position; wherein the plate or rod (<NUM>) moves upwards relative to the sled (<NUM>) when in the extended position.