Vehicle restraint

Vehicle restraints for use at loading docks are disclosed herein. In some embodiments, a vehicle restraint can include a frame mountable relative to a loading dock face, a restraining structure configured to engage, for example, a Rear Impact Guard (RIG) of a shipping vehicle, and a linkage operably coupling the restraining structure to the frame. The linkage can include a collapsible strut operably coupled between the frame and the restraining structure. In operation, the linkage can be raised to engage the restraining structure with the RIG and prevent the vehicle from moving away from the dock face. Additionally, the restraining structure can be disengaged from the RIG by collapsing the strut, even if the RIG is imparting a significant load on the restraining structure that might otherwise bind the restraining structure in the engaged position.

TECHNICAL FIELD

The following disclosure relates generally to vehicle restraints and, more particularly, to vehicle restraints for restraining transport trucks, trailers, and/or other vehicles at loading docks.

BACKGROUND

Vehicle restraints are used in the material handling industry to prevent vehicles from moving away from a loading dock while the vehicle is being loaded and/or unloaded with goods or materials. In general, these devices act as substitutes for wheel chocks. But unlike wheel chocks, conventional vehicle restraints typically engage the Rear Impact Guard (“RIG”) bar of the vehicle. RIG bars (which can also be referred to as “ICC” bars) are horizontal members that extend across the rear end of the vehicle. In the U.S., regulations require that the vertical distance between the bottom edge of the RIG bar and the ground not exceed 22 inches at any point across the full width of the member, and that the rearmost surface of the RIG bar be within 12 inches of the rear extremity of the vehicle.

Trailers and other transport vehicles tend to “float” up and down as they are loaded and/or unloaded at loading docks. More specifically, as weight is moved off and on the vehicle it moves up and down, respectively, thereby varying the vertical position of the RIG bar relative to the ground. Some restraint systems have been developed to accommodate this vehicle movement, and they generally fall into three categories. The first category employs a restraining member operably coupled to a carriage having rollers or similar devices which ride on tracks mounted to the face of the loading dock. See, for example, the vehicle restraints disclosed in U.S. Pat. Nos. 4,472,099, 4,443,150, 4,282,621, 4,264,259 and 4,695,216, each of which is incorporated herein by reference in its entirety. The use of a vertically moving carriage provides a range of motion to engage RIG bars at different heights. However, the carriage rollers are subjected to vehicle restraint loads while moving up and down in response to vehicle loading and unloading. As a result, this type of restraint generally requires relatively high maintenance to service the moving carriage and related parts. Additionally, some of these vehicle restraints are designed to operate in response to vehicle impact. More specifically, to operate the restraint the vehicle backs into the loading dock until the RIG contacts the restraint system, causing the restraint system to move a locking hook into engagement with the RIG bar. The repeated shock of the RIG bar on such systems can cause significant component wear. Additionally, because the carriage track is mounted to the dock face, in some situations it may interfere with operation of the dock leveler, particularly on relatively low loading docks.

A second category of restraint system includes a vertical bar or similar restraining member that is moved into position in front of the RIG bar to prevent forward movement of the vehicle away from the loading dock. Various types of mechanisms have been proposed to position the bar in such systems, such as those disclosed in, for example, U.S. Pat. Nos. 4,634,334, 4,605,353, and 4,784,567, each of which is incorporated herein by reference in its entirety. In particular, some of these restraint systems pivot the bar into the vertical position to restrain the vehicle. One shortcoming of this type of system, however, is that the raised height of the bar is constant and, as a result, it may interfere with hitches and/or other equipment mounted to the underside of the vehicle.

A third category of restraint system utilizes one or more hooks which pivot about a fixed hinge mounted to the dock wall. See, for example, U.S. Pat. Nos. 4,605,353, 4,208,161 and 4,605,353, each of which is incorporated herein by reference in its entirety. In this type of system, the distance from the dock wall to the hook varies as the hook moves through its arc of travel to engage the RIG bar, and as the vehicle moves up and down during the loading/unloading process. If the final distance between the hook and the dock face after the loading/unloading process is less than the distance when the process started, the RIG bar may impart such a high load on the hook that the hook may not release when desired.

All of the restraint systems described above operate by restricting horizontal movement of the transport vehicle away from the loading dock. This movement may be caused by a variety of factors, such as the driver inadvertently attempting to drive away from the loading dock while the restraint is engaged, the slope of the ground, and/or the kinetic energy imparted to the vehicle by the loading and unloading of goods and materials. Of these, the most common causes of vehicle horizontal movement are the accelerations/decelerations imparted to the vehicle by loading and unloading of goods and materials by hand, fork lift, etc.

Regardless of the cause of the movement, if the vehicle has moved away from the loading dock at the conclusion of the loading/unloading process, it can put a load on the restraining member of the restraint system, whether the restraining member is a blocking member, a rotating hook, etc. Although this situation is not unsafe, it can lead to an operational issue referred to as “hook pinch.” Hook pinch occurs with vehicle restraint systems when the restraining member is loaded by the transport vehicle to the extent that, when the dock operator attempts to disengage the restraining member from the RIG bar and return the restraint system to the stored position, the operator is unable to do so because of binding between the restraining member and the RIG bar caused by the vehicle load. More specifically, in such situations the restraint system is not powerful enough to overcome the binding force and disengage the restraining member from the RIG bar. Typically, the only way to relieve this force so that the restraining member can be disengaged is to have the vehicle driver move the transport vehicle a slight distance back against the dock bumpers and away from the restraining member. This operation is called “bump-back,” and can be a time-consuming effort in that it requires coordination between the dock operator and the transport vehicle driver. Accordingly, it would be advantageous to provide an improved vehicle restraint system that addresses the problem of hook pinch.

DETAILED DESCRIPTION

The following disclosure describes various embodiments of vehicle restraints that can be used to prevent trucks, trailers and other transport vehicles from moving away from a loading dock during a loading and/or unloading process. As discussed above, one operational issue that can affect the performance of vehicle restraints is known as “hook pinch.” Hook pinch occurs when vehicle movement away from the loading dock causes the restraining member to bind to such an extent that the restraint system cannot be disengaged until the vehicle is moved back toward the loading dock face to relieve the binding load in an operation referred to as “bump-back.” As described in greater detail below, vehicle restraints configured in accordance with some embodiments of the present technology can eliminate or at least greatly reduce the need for bump-back by use of a linkage that includes a collapsible member (e.g., a “break-away strut”). The collapsible member remains rigid (or at least substantially rigid) during RIG bar engagement, but collapses or otherwise retracts in response to a release command, thereby causing the restraining member to move both forward and downward to disengage the RIG bar. By moving slightly forward relative to the RIG bar, the restraining member avoids hook pinch and, as a result, the need for vehicle bump-back is eliminated.

Certain details are set forth in the following description and inFIGS. 1-9Gto provide a thorough understanding of various embodiments of the present technology. In other instances, well-known structures, materials, operations and/or systems often associated with vehicle restraint systems, loading docks, etc. are not shown or described in detail in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments of the technology. Those of ordinary skill in the art will recognize, however, that the present technology can be practiced without one or more of the details set forth herein, or with other structures, methods, components, and so forth.

The accompanying Figures depict embodiments of the present technology and are not intended to be limiting of its scope. The sizes of various depicted elements are not necessarily drawn to scale, and these various elements may be arbitrarily enlarged to improve legibility. Component details may be abstracted in the Figures to exclude details such as position of components and certain precise connections between such components when such details are unnecessary for a complete understanding of how to make and use the invention. Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles and features without departing from the spirit or scope of the present invention. In addition, those of ordinary skill in the art will appreciate that further embodiments of the invention can be practiced without several of the details described below. In the Figures, identical reference numbers identify identical, or at least generally similar, elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refers to the Figure in which that element is first introduced. For example, element110is first introduced and discussed with reference toFIG. 1.

FIG. 1is an isometric view of a vehicle restraint100configured in accordance with an embodiment of the present technology. In the illustrated embodiment, the vehicle restraint100is installed at a loading dock101at a warehouse or other building. As is well known, the loading dock101can include an opening106in the building positioned directly above a dock wall104that extends vertically upward from a driveway102. In most applications, the vehicle restraint100would be positioned generally in the center, or at least approximately in the center, of the building opening106. Although not shown inFIG. 1, the loading dock can also include dock bumpers mounted to the dock wall104beneath the opening106, and a dock leveler adjacent to the building floor to provide a ramp for moving materials into and/or out of a shipping trailer backed up to the loading dock101and engaged with the vehicle restraint100.

In the illustrated embodiment, the vehicle restraint100includes a restraining structure123operably coupled to a frame108by a linkage117. The frame108includes a housing110that extends outwardly from a base114. The base114can be fixedly attached to the dock wall104by a plurality of suitable fasteners116(e.g., anchor bolts, screws, etc.) that extend through corresponding holes in the base114and engage the material in the dock wall104. In other embodiments, however, the frame108can be mounted directly to the driveway102in front of the dock wall104. The housing110includes opposing side plates112(identified individually as a first side plate112aand a second side plate112b). The linkage117includes a main arm119and an upper arm120. The main arm119is operably disposed between the side plates112and pivotally coupled to the base114by a cylindrical pivot pin142. In the illustrated embodiment, the main arm119is composed of a two generally-matching and spaced-apart arm members118(identified individually as a first arm member118aand a second arm member118b). In other embodiments, it is contemplated that the main arm119can be constructed from a single member, such as a single member having opposing side flanges. Distal end portions of the arm members118are pivotally coupled to an upper arm120by a pivot pin132. In the illustrated embodiment, the upper arm120can have a generally inverted U-shaped cross section with opposing side flanges with corresponding bores that receive the pivot pin132and enable the upper arm120to rotate back and forth about the pivot pin132.

In one aspect of the illustrated embodiment, the restraining structure123includes a hook assembly124. The hook assembly124can include a first vertical surface126that serves as a primary vehicle restraint for engaging a RIG bar of a vehicle, and a spring-loaded secondary hook128that includes a second vertical surface129which can serve as a secondary restraint for vehicles having the RIG bar positioned further aft toward the dock wall104. The hook assembly124is pivotally coupled to an upper end portion of the upper arm120by a pivot pin134. Additionally, two hook struts122(identified individually as a first hook strut122aand a second hook strut122b) are operably coupled between the main arm119and the hook assembly124by a pivot pin138that pivotally couples one end of each hook strut122to the hook assembly124, and a pivot pin140that pivotally couples the opposite end of each hook strut122the main arm119.

In another aspect of the illustrated embodiment, biasing members130(identified individually as a first biasing member130aand a second biasing member130b) are operably coupled between the frame108and the main arm119. More specifically, in the illustrated embodiment the first biasing member130ais operably coupled between the first arm member118aand the first side plate112a, and the second biasing member130bis similarly coupled between the second arm member118band the second side plate112b. By way of example, the biasing members130can be telescoping gas springs that are configured to exert a force against the main arm119when compressed, thereby biasing the main arm119(and hence the linkage117) toward an upper position in which the hook assembly124can engage a RIG bar (not shown) on a transport vehicle. In other embodiments, other types of biasing members can be used to bias the linkage117toward the upward position. Such biasing members can include, for example, suitably positioned compression springs, torsion springs, mechanical actuators, electrical, hydraulic, and/or pneumatic actuators, etc. Manual systems could also be employed to raise or at least partially raise the linkage117for RIG bar engagement.

In a further aspect of the illustrated embodiment, the vehicle restraint110includes a collapsible strut160which has a proximal end portion pivotally coupled to the side plates112of the housing110via a pivot shaft162, and a distal end portion pivotally coupled to a lower end portion of the upper arm120by a corresponding pivot pin136. As described in greater detail below, the collapsible strut160is a collapsible structure that maintains a generally straight and rigid configuration during engagement of the hook assembly124with a RIG bar, but is configured to collapse or “break-away” and reduce its overall length in response to a release command from, for example, the dock operator. This causes the hook assembly124to move downwardly and away from the dock face140, thereby disengaging the hook assembly124from the RIG bar without binding or “hook pinch.”

In another aspect of the illustrated embodiment, the vehicle restraint100includes an actuator156operably coupled between the main arm119and the collapsible strut160. More specifically, the actuator156includes a first end portion180pivotally coupled to a first pivot arm144, and a second end portion182pivotally coupled to a second pivot arm166. The first pivot arm144includes a link146and a lever150which extend outwardly from a sleeve148. The link146includes a proximal end portion fixedly attached to the sleeve148, and a distal end portion pivotally coupled to the first end portion180of the actuator156. The lever150includes a proximal end portion fixedly attached to the sleeve148, and a distal end portion that includes a hook feature151(e.g., a notch or recess). Upward movement of the lever150is limited by a stop152. The sleeve148includes a cylindrical bore147that slidably receives the pivot pin142and enables the first pivot arm144to rotate freely about the pivot pin142. As described in greater detail below, in operation, initial extension of the actuator156rotates the first pivot arm144downwardly about the pivot pin142until the hook feature151on the lever150engages a main arm pin154. The main arm pin154extends outwardly from the second arm member118bthrough an arcuate slot178in the side plate112b. Further downward rotation of the first pivot arm144drives the main arm pin154(and hence the main arm119) downwardly to retract the linkage117into the housing110.

At the opposite end of the actuator156, the second pivot arm166includes first and second side plates167aand167b, respectively, that form a clevis-type connection to the second end portion182of the actuator156. An engagement pin170extends horizontally between the two side plates167, and a proximal end portion of each of the side plates167includes a cylindrical bore168that slidably receives the pivot shaft162, enabling the second pivot arm166to rotate back and forth freely on the pivot shaft162. In the illustrated embodiment, the vehicle restraint110further includes a break-away lever164disposed between the side plates167of the second pivot arm166. The break-away lever164has a proximal end portion fixedly attached to the pivot shaft162, and a distal end portion having a hook feature176(e.g., a notch or recess). As described in greater detail below, the hook feature176is configured to receive the engagement pin170as extension of the actuator156rotates the second pivot arm166outwardly about the pivot shaft162. Once the engagement pin170contacts the hook feature176, continued outward rotation of the second pivot arm166also rotates the break-away lever164outwardly. Because both the break-away lever164and the proximal end portion of the collapsible strut160are fixedly attached to the pivot shaft162, outward rotation of the break-away lever164causes the proximal end portion of the collapsible strut160to rotate downwardly. Outward rotation of the second pivot arm166is limited by an actuator stop172that is fixedly attached to the second side plate112bof the housing110.

In the illustrated embodiment, the actuator156is a linear actuator that can include a telescoping pushrod that can be driven outwardly and inwardly by, for example, a bidirectional electric motor (e.g., a stepper motor) operably coupled to a suitable lead screw and drive nut arrangement. The actuator156can receive operational power and/or signals from a controller184via one or more electrical links (e.g., wires). The controller184can include one or more processing devices (e.g., a programmable logic controller (PLC)) configured to operate in accordance with instructions stored on computer-readable media in response to, for example, dock operator inputs via a control panel185or other suitable user interface operably connected to the controller184. The controller184can receive power from a suitable power source (not shown) such as facility power, a battery, etc. In other embodiments, the actuator156can be a hydraulic actuator, a pneumatic actuator, as well as other types of mechanically and electrically operated linear actuators. In yet other embodiments, it is contemplated that the actuator156can be replaced by a suitable arrangement of a rotational actuator, and/or a manually operable system for controlling movement of the first pivot arm144, the second pivot arm166, and/or the associated components as described herein.

As those of ordinary skill in the art will appreciate, most of the components of the vehicle restraint100described above can be made from suitable types of known materials that are welded or otherwise joined together (e.g., bolted together) using suitable techniques well established in the art for cost-effectively manufacturing vehicle restraint systems and similar structures. For example, in various embodiments portions of the frame108, the main arm118, the upper arm120, the hook assembly124, the collapsible strut160, etc. can be made from mild or carbon steel (e.g., ASTM A36, A36M, A53, etc.) plates, bars, tubes, angles, beams, etc. of appropriate gauge which are cut or otherwise formed to shape and welded, riveted or bolted together using conventional methods well known in the art. The various pivot pins, fasteners, etc. used herein can also be made from suitable steels, such as carbon steels, alloy steels, stainless steels, etc. In other embodiments, other materials (e.g., aluminum) and/or methods can be used to manufacture and/or assemble various embodiments of the vehicle restraints described herein without departing from the spirit or scope of the present disclosure.

FIG. 2is an enlarged front isometric view of the collapsible strut160configured in accordance with an embodiment of the present technology. (Although referred to herein as a collapsible strut for ease of reference, the collapsible strut160can also be referred to as, for example, a “collapsible member,” “break-away member,” “break-away arm,” etc.) In the illustrated embodiment, the collapsible strut160includes a first link (identified as an upper link262) and a second link (identified as a lower link264) pivotally coupled together by a joint270therebetween. The lower link264includes a pair of legs274(identified individually as a first leg274aand a second leg274b) fixedly attached (e.g., welded) to a tube276. The tube276includes a central bore280configured to receive the pivot shaft162(FIG. 1). The pivot shaft162extends outwardly from both sides of the tube276to pivotally couple the collapsible strut160to the side plates112of the housing110(FIG. 1). In one aspect of this embodiment, the tube276is fixedly attached (e.g., welded, bolted, or otherwise fastened) to the pivot shaft162so that rotation of the pivot shaft162about its central axis also rotates the lower link264. The joint270includes a first link tube portion272aand a second link tube portion272bspaced apart from each other to define a gap therebetween that receives a first end portion269of the upper link262. The link tube portions272are fixedly attached (e.g., welded) to upper portions of the legs274, and have bores278which are coaxially aligned with a bore268extending through the first end portion269. A pivot pin271extends through the link tube bores278and the bore268in the first end portion269to pivotally join the upper link262to the lower link264. The upper link262includes a second end portion267having a bore266that receives the pivot pin136for pivotally coupling the upper link262to the upper arm120(FIG. 1).

In one aspect of the illustrated embodiment, the collapsible strut160further includes a link stop285fixedly attached (e.g., welded) to at least the first leg274aof the lower link264. In the illustrated embodiment, the link stop285is a piece of material (e.g., steel) that extends upwardly from the lower leg264and adjacent to the upper link262. As described in greater detail below, in operation the link stop285prevents the upper link262from rotating in a counterclockwise (CCW) direction relative to the lower link264about the joint270beyond a slightly “over-center” position. More specifically, when the upper link262is bearing against the link stop285as shown inFIG. 2, the upper link262is positioned in a stable, slightly over-center position relative to the lower link264, such that the upper link262is generally in co-linear alignment with the lower link264, but angled slightly toward and against the link stop285in the CCW direction. In such a position (which can, for example, be referred to as a “locked” position), the collapsible strut160can sustain compression loads as a generally rigid member.

In another aspect of this embodiment, the collapsible strut160further includes a biasing member282configured to bias the upper link262against the link stop285. More specifically, in the illustrated embodiment the biasing member282is a torsion spring having a series of coils286that wrap around the second link tube portion272b, and an arm284that bears against the upper link262. An end portion of the spring coils286is engaged or otherwise fixed to the second link tube portion272b, and the coils286are preloaded in torsion before the arm284is positioned behind the upper link262. As a result, the arm284biases the upper link262against the link stop285. As described in greater detail below, the biasing member282can act as a “reset member” that tends to drive the upper link262into alignment with the lower link264and maintain the collapsible strut160as a rigid member, but will also permit the upper link262to rotate away from the link stop285in a clockwise (CW) direction to thereby “collapse” or retract the collapsible strut160when a sufficient torque is applied to the lower link264in the CCW direction relative to the pivot shaft162(FIG. 1). By way of example, in some embodiments the biasing member282can be made out of a suitable gauge spring steel. In other embodiments, however, the collapsible strut160can include other spring configurations and/or other biasing members for biasing the upper link262as described herein.

FIGS. 3A-3Fare a series of side views illustrating the vehicle restraint100in various stages of operation in accordance with an embodiment of the present technology. Referring first toFIG. 3A, the hook assembly124has engaged an RIG310(shown in cross-section) of a vehicle (e.g., a shipping trailer; not shown) which has backed up to the dock wall104for the loading and/or unloading of goods, materials, etc. through the opening106in a warehouse or other building. More specifically, in this view the actuator156is fully retracted so that the lever150contacts the upper stop152. This permits the main arm pin154to move upwardly in the slot178as the biasing members130raise the main arm119to engage the hook assembly124with the RIG310and prevent the vehicle from moving away from the dock wall104. Moreover, the compressibility of the biasing members130enable the hook assembly124to move upwardly and downwardly as necessary to maintain engagement with the RIG310as the vehicle is loaded and/or unloaded with goods or materials.

As also shown inFIG. 3A, the angular position of the upper link262of the collapsible strut160can be defined by a first centerline301that extends through the central axes of the pivot pin136and the pivot pin271. Similarly, the angular position of the lower link264can be defined by a second centerline302that extends through the central axes of the pivot pin271and the pivot shaft162. In some embodiments, during elevation of the hook assembly124and engagement with the RIG310, the biasing member282(FIG. 2) biases the upper link262against the link stop285in a slight “over-center” position in the CCW direction so that the first centerline301is positioned at a slight angle A (e.g., an angle of from about 1 degree to about 5 degrees) relative to the second centerline302. This creates a stable strut configuration that can sustain compression loads without buckling about the joint170during the hook elevation and engagement phases of restraint operation.

To disengage the vehicle restraint110from the RIG310, the actuator156is extended. More specifically, an operator (e.g., a dock operator) can provide a release command to the controller184via the control panel185(FIG. 1) and/or other user interface. The controller184can in turn energize an electric motor on the actuator156, driving the actuator156to extend outwardly in length. As shown inFIG. 3B, as the actuator156extends, the first end180moves to the right inFIG. 3Band rotates the first pivot arm144in the counterclockwise (CCW) direction about the pivot pin142until the hook feature151on the lever150comes into contact with the main arm pin154. Referring next toFIG. 3C, as the actuator156continues to extend, the second end182moves to the left inFIG. 3Cand rotates the second pivot arm166in the CCW direction about the pivot shaft162and away from a forward stop320until the engagement pin170is received by the hook feature176in the break-away lever164(see alsoFIG. 1). As noted above, both the break-away lever164and the lower link264of the collapsible strut160are fixedly attached to the pivot shaft162. As a result, when the engagement pin170contacts the break-away lever164and drives it outwardly in the CCW direction, the break-away lever164applies a torque to the pivot shaft162which in turn applies a torque to the lower link264of the collapsible strut160, causing the lower link264to also rotate in the CCW direction. As shown inFIG. 3D, this rotation of the lower link264causes the upper link262to overcome the biasing force of the biasing member284(FIG. 2) and rotate away from the link stop285in the clockwise (CW) direction about the pivot pin271. Once the upper link262rotates in the CW direction to an over-center position in the direction opposite the link stop285, continued rotation of the lower link164in the CCW direction (and/or a compression force on the collapsible strut160from the upper arm120) causes the upper link262and the lower link264to rotate inwardly toward each other as the collapsible strut160“collapses,” thereby reducing the overall length of the collapsible strut160. Collapsing the collapsible strut160in the foregoing manner causes the hook assembly124to move downwardly and forwardly to disengage from the RIG310without binding, even if the RIG310was bearing against the vertical surface129with a force sufficient to create “hook pinch” in conventional vehicle restraints.

Referring next toFIG. 3E, continued extension of the actuator156causes the second pivot arm166to continue rotating outwardly in the CCW direction until the second end182of the actuator156contacts the actuator stop172. Further extension of the actuator156causes the first end180to drive the first pivot arm144further in the CCW direction about the pivot pin142, thereby driving the main arm pin154further downwardly in the slot178until the restraint linkage117is fully retracted into the housing110as shown inFIG. 3F. Once the linkage117is fully retracted into the housing110, the torque exerted by the biasing member282against the upper link262of the collapsible strut160can drive the upper link262in the CCW direction about the pivot pin271until the upper link262contacts the link stop285, thereby returning the collapsible strut160to its fully extended position. As described above in reference toFIGS. 2 and 3A, in this position the upper link262is aligned, or at least approximately in co-linear alignment with the lower link264, and the collapsible strut160behaves as a “rigid” strut or member extending between the frame108and the upper arm120. The collapsible strut160maintains this configuration during raising of the vehicle restraint100and engagement with a RIG.

To raise the linkage117from the position shown inFIG. 3F, the actuator156is retracted as shown inFIG. 3Aso that the biasing members130can drive the main arm119upwardly. As described above with reference toFIG. 3A, this raises the linkage117and brings the hook assembly124into engagement with the RIG310. In some embodiments of the vehicle restraint100, it is possible for the collapsible strut160to remain in a slightly collapsed configuration while the linkage117is being raised by the biasing members130to bring the hook assembly124into engagement with the RIG310. More specifically, with reference toFIG. 3F, as the actuator156retracts from this position, the first end180moves to the left, thereby causing the lever150to rotate in the clockwise direction about the pivot pin142, which in turn releases the main arm pin154and allows the main arm119to begin rotating upwardly under the force of the biasing members130. As this happens, the second end182of the actuator156stays in position against the actuator stop172, which in turn holds the lower link264of the collapsible strut160down in the fully retracted position and prevents it from rotating clockwise about the pivot shaft162. However, the upper link262of the collapsible strut160is able to rotate about the pivot pin271in the clockwise direction in response to the upward rotation of the main arm119. As a result, the collapsible strut160can assume a partially collapsed configuration similar to that shown in, for example,FIG. 3E or 3D, as the linkage117starts to rise, and maintain such a configuration throughout the upward movement of the linkage117as it moves the hook assembly124into engagement with the RIG310. One undesirable consequence of having the collapsible strut160be slightly collapsed during raising of the linkage117, is that it causes the hook assembly124to move in a generally upward but slightly arcuate path as indicated by the dotted line330inFIG. 3D. As a result, the hook assembly124can become bound against the RIG310and/or prevent full engagement of the hook assembly124with the RIG310if the RIG310is in a forward-most position prior to engagement. Conversely, if the collapsible strut160maintains its “rigid” over-center configuration as shown in, for example,FIG. 3Athroughout upward movement of the linkage117, the hook assembly124moves only upwardly in a straight vertical path because of the configuration of the linkage117. Straight vertical movement of the hook assembly124is desired to avoid binding of the hook assembly124during engagement with the RIG310. Accordingly, in some embodiments it would be advantageous for the collapsible strut160to remain in the over-center configuration throughout upward movement of the linkage117and engagement of the hook assembly124with the RIG310.

FIG. 4is a partially exploded isometric view of a vehicle restraint400having a main arm hold down mechanism490configured in accordance with an embodiment of the present technology. As described in greater detail below, the hold down mechanism490can enable the collapsible strut160to maintain its rigid over-center configuration throughout elevation of the hook assembly124. The vehicle restraint400is at least substantially similar in structure and function to the vehicle restraint100described in detail above, and indeed, many components of the vehicle restraint400can be identical to the corresponding components of the vehicle restraint100described above. For example, the vehicle restraint400includes a linkage417for raising and lowering the hook assembly124. The linkage417includes a main arm419that is pivotally coupled to the base114and is operably disposed between a first side plate412aand a second side plate412bof a housing410. In the illustrated embodiment, the housing410, the main arm419and the other components of the linkage417are substantially the same as the corresponding components of the vehicle restraint100described above except for the modifications described below to accommodate the main arm hold down mechanism490.

In the illustrated embodiment, the main arm hold down mechanism490includes a restraining member420that cooperates with a first pivot arm444and a second pivot arm466. The second pivot arm466can be identical to the second pivot arm166described in detail above with reference to, e.g.,FIG. 1except that the second pivot arm466can include a cylindrical catch pin404that extends inwardly from the side plate167a.FIG. 5is an enlarged isometric view of the first pivot arm444. Referring toFIGS. 4 and 5together, the first pivot arm444is at least generally similar in structure and function to the first pivot arm144described in detail above with reference toFIG. 1. In this particular embodiment, however, the first pivot arm444includes a lever450having a second hook feature553in addition to the first hook feature151of the lever150described above. Additionally, the first pivot arm444also includes a post554extending outwardly from the lever450. As shown inFIG. 4, a biasing member403(e.g., a tension spring) attaches between the post554and a bracket452on the housing410to bias the first pivot arm444downwardly in the counterclockwise (CCW) direction.

FIG. 6is an enlarged isometric view of the restraining member420. Referring toFIGS. 4 and 6together, in the illustrated embodiment the restraining member420includes a cylindrical bore602that rotatably receives the pivot shaft162. Additionally, the restraining member420includes an arcuate slot604and a cylindrical engagement pin422. The arcuate slot424includes an opening on one end and an end portion606on the other end, and is configured to receive the catch pin404of the second pivot arm466therein. The engagement pin422extends inwardly from the restraining member420and is configured to move back and forth in an arcuate slot424that is formed in the side plate412bof the housing410.

FIG. 7is an enlarged side view of the housing410. Referring toFIGS. 4 and 7together, in addition to the arcuate slot424, the side plate412bcarries a stop block402that limits CCW rotation of the restraining member424about the pivot shaft162. Additionally, in some embodiments a cross member418can be installed between the first side plate412aand the second side plate412band positioned to contact the collapsible strut160when the restraint400is in the fully retracted position (as shown in, for example,FIG. 3F) to force the collapsible strut160into the over-center configuration.

FIG. 8is an enlarged isometric view of the distal end portion of the main arm419. As with the main arm119described in detail above, the main arm419includes two spaced-apart arm members418(identified individually as a first arm member418aand a second arm member418b). In the illustrated embodiment, however, the second arm member818bincludes an engagement slot802in a lower edge portion thereof that is configured to receive the engagement pin422of the restraining member420. In this regard, the engagement slot802includes a contact surface806leading from an opening of the engagement slot802to a notch804.

In general, operation of the vehicle restraint400is identical to operation of the vehicle restraint100described above, with the following exceptions related to operation of the main arm hold down mechanism490.FIGS. 9A-9Gare a series of side views of a portion of the vehicle restraint400illustrating operation of the hold down mechanism490in accordance with an embodiment of the present technology. InFIGS. 9A-9C, the second pivot arm466, the break-away lever164, the actuator156and the collapsible strut160have been omitted for clarity, but the second pivot arm466has been included inFIGS. 9D-9Gfor purposes of illustration. Referring first toFIGS. 9A-9Cin combination withFIG. 4, in operation the hook assembly124is disengaged from the RIG310in the same manner described in detail above with reference toFIGS. 3A-3Fexcept that as the main arm419moves downwardly into the housing410as shown inFIGS. 9A and 9B, the contact surface806of the engagement slot802comes into contact with the engagement pin422of the restraining member420. Normally the restraining member420is biased against the stop block402by a counterweight and/or a torsional biasing member (e.g., a torsion spring). However, when the contact surface806contacts the engagement pin422, it causes the engagement pin422to move upwardly in the engagement slot802and rotates the restraining member420away from the stop block402in the CW direction about the pivot shaft162. As the main arm419continues moving downwardly, the engagement pin422continues moving upwardly relative to the engagement slot802until it drops into the notch804as show inFIG. 9C. In this position, the restraining member420holds the main arm419down in the fully stored position.

Raising the vehicle restraint400for engagement with the vehicle RIG310is described below with reference toFIGS. 9D-9Gin conjunction withFIGS. 4 and 3F. AlthoughFIG. 3Fillustrates the vehicle restraint100and not the vehicle restraint400,FIG. 3Fwill be referred to herein to facilitate an understanding of the operation of the vehicle restraint400. To raise the vehicle restraint400and engage the RIG310, the actuator156is retracted from the position shown inFIG. 3F. More specifically, an operator (e.g., a dock operator) can provide an engage command to the controller184via the control panel185(FIG. 1) and/or other user interface. The controller184can in turn energize the actuator156for retraction. As the actuator156retracts, the first end180moves to the left and rotates the first pivot arm444in the CW direction about the pivot pin142until the tension in the biasing member403counterbalances the force of the actuator156. When this occurs, the first end180of the actuator156stops moving to the left, and the second end182begins moving to the right, which in turn causes the second pivot arm466to rotate away from the actuator stop172in the CW direction about the pivot shaft162. This action enables the first pivot arm444to rotate back in the CCW direction until the first hook feature151on the lever450(FIG. 5) comes into contact with the main arm pin154(see, e.g.,FIG. 3F). This stops CCW rotation of the first pivot arm444, and continued retraction of the actuator156causes the second pivot arm466to continue rotating in the CW direction until the catch pin404(FIG. 4) comes into contact with the end portion606of the arcuate slot604in the restraining member420(FIG. 6) as shown inFIG. 9E. At this time, the engagement pin422on the restraining member420is still engaged with the notch804in the main arm419as shown inFIG. 9C, thereby holding the main arm419down in the fully stored position. Contact of the catch pin404with the end portion606of the arcuate slot604as shown inFIG. 9Etemporarily halts CW rotation of the second pivot arm466. As a result, continued retraction of the actuator156causes the first pivot arm444to rotate in the CW direction about the pivot pin142until the second hook feature553on the lever450(FIG. 5) comes into contact with the main arm pin154. This contact momentarily stops the CW rotation of the first pivot arm444, and continued retraction of the actuator156now causes the second pivot arm466to continue rotating in the CW direction about the pivot shaft162, thereby driving the restraining member420away from the stop block402in the CW direction by means of the catch pin404, as shown inFIG. 9F. As the restraining member420rotates in the CW direction, the engagement pin422begins moving from left to right in the arcuate slot424in the second side plate412bof the housing410(FIG. 7), as also shown inFIG. 9F. Additionally, as the engagement pin422moves in this direction, it moves out of the notch804in the second arm member818b(FIG. 8), as further shown inFIG. 9F. This enables the main arm419to rotate upwardly and out of the housing410in the CW direction under the force of the biasing members130, as shown inFIG. 9Gto bring the hook assembly124into engagement with the RIG310.

As described above, the hold down mechanism490prevents the main arm419from rotating upwardly from the stored position until the second pivot arm466has rotated fully in the CW direction into contact with the forward stop320. As a result, the second pivot arm466does not prevent the lower link264of the collapsible strut160from rotating CW once the main arm419starts to rise. This enables the biasing member282to hold the collapsible strut160in the rigid, over-center position throughout the entire upward motion of the hook assembly124. As a result, the hook assembly124only moves in a straight, vertical direction to engage the RIG310. This can prevent the binding and/or incomplete engagement that might otherwise occur if the collapsible strut160maintained a slightly collapsed configuration that caused the hook assembly124to move a slight arc during RIG engagement.

One advantage of some embodiments of the vehicle restraint described above over existing blocking-style vehicle restraints is that the forward and/or downward movement of the hook assembly124provided by the collapsible strut160can eliminate or at least greatly reduce the operational difficulties associated with hook-pinch. More specifically, whereas conventional vehicle restraints may require communication between the dock operator and the vehicle operator so that the vehicle operator can back the shipping vehicle against the loading dock (e.g., “bump-back”) to alleviate hook-pinch and enable the restraint to be retracted, embodiments of the vehicle restraint described above can eliminate the need for such communication and coordination. Moreover, reducing the operating loads on the vehicle restraint often caused by hook-pinch can significantly reduce the operational damage that vehicle restraints sustain, thereby reducing the frequency maintenance and/or necessary repairs.

Although the collapsible strut160of the illustrated embodiment includes the collapsible links262and264, in other embodiments, other types of collapsible struts and/or collapsible members are contemplated for use with vehicle restraints configured in accordance with the present technology. For example, in other embodiments the collapsible strut160can be replaced with, for example, an axially extensible member (e.g., a telescoping member) that can maintain a preset length during raising and engagement of the hook assembly124, but can then be telescopically retracted or otherwise collapsed in response to, for example, a release command. For example, in one embodiment the collapsible strut160could be replaced by a hydraulic, pneumatic, or electrical actuator that maintains a given length during raising and engagement of the hook assembly124, but then receives an appropriate signal (e.g., an electrical signal) causing, for example, a valve to open in the case of the hydraulic or pneumatic actuator, or an electrical stepper motor to operate, to thereby retract the telescoping member to release the hook assembly124. Accordingly, as those of ordinary skill in the art will appreciate, restraint systems configured in accordance with the present technology can include various types of collapsible or otherwise retractable structures in place of and/or in addition to the collapsible strut160.

Furthermore, the described features, advantages, and characteristics of the present technology may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the present technology can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present technology.

Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further implementations of the invention.

The above Detailed Description of examples and embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific examples for the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while operations of disclosed devices may be presented in a given order, alternative implementations may perform operations in a different order, and/or some operations may be deleted, moved, added, subdivided, combined, and/or modified to provide alternative or sub-combinations. The teachings of the technology provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various examples described above can be combined to provide further implementations of the invention. Some alternative implementations of the invention may include not only additional elements to those implementations noted above, but also may include fewer elements. Further any specific numbers noted herein are only examples: alternative implementations may employ differing values or ranges.

While the above description describes various embodiments of the invention and the best mode contemplated, regardless how detailed the above text, the invention can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the present disclosure. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific examples disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the invention under the claims.

From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the various embodiments of the invention. Further, while various advantages associated with certain embodiments of the invention have been described above in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited, except as by the appended claims.

Although certain aspects of the invention are presented below in certain claim forms, the applicant contemplates the various aspects of the invention in any number of claim forms. Accordingly, the applicant reserves the right to pursue additional claims after filing this application to pursue such additional claim forms, in either this application or in a continuing application.