Abstract: The doors of a type including closure elements are guided at the side and which are provided with a drive mechanism. To simplify the drive mechanism, and to increase the operational reliability, there are inventively provided one or more motors that are secured to the closure elements and that have a gear wheel which meshes with a track that extends parallel to the lateral guide rails. Preferably, the gear wheels and the lateral guide rollers are coaxially disposed, with the guide rollers being freely rotatable.

Abstract: A bolt connection for connecting a hollow profiled member to a profiled member disposed transverse thereto where connection by welding is inadequate. A plate-like member that is resistant to bending is displaceably supported at one end against the inner surface of the hollow profiled member, and is supported at the other end against an abutment that is disposed remote from the aforementioned inner surface. The length of the plate-like member is slightly greater than the inside height of the hollow profiled member. The bottom of the hollow profiled member is preferably supported on a projection of the other profiled member. The abutment is preferably disposed at the top with the displaceable end of the plate-like member being at the bottom. By tightening the bolt that acts upon the plate-like member, a tight, releasable connection is provided.

Abstract: A dock leveler that includes a pivotable bridge plate and an extension that can be moved back and forth relative to the latter and serves for reseting the bridge plate on a platform that is to be loaded or unloaded. A switch is provided that effects or permits automatic return of the dock leveler into the neutral or rest position. To ensure that return to the neutral position reliably occurs only when no platform is in the vicinity of the dock leveler, there is provided below the tip of the extension a sensing element that is movable in the direction toward the bridge plate and that can be contacted by the platform. The sensing element activates the switch except when the platform contacts the sensing element, at which time the switch is deactivated.

Abstract: A transfer bridge for bridging across railroad tracks. The transfer bridge includes a bridge plate that can be pivoted from a vertical rest position into a horizontal operative position, in which the free end of the bridge plate rests upon a platform next to the tracks. In addition, a travel mechanism that is movable parallel to the tracks is associated with the bridge. In order to achieve a simplified and smaller construction for the travel mechanism, the latter is provided with an upwardly extending boom that is held in a guide rail to keep it from tilting.

Abstract: A transfer bridge for ramps, docks, or other platforms. The retractable and extensible extension of the bridge plate is mounted on guide elements. Provided at the edges of the bridge are longitudinally extending racks that mesh with two pinions that are rigidly interconnected. In order to assure a rattle-free guidance, support wheels are associated with the pinions for relieving the latter of radial load. These support wheels roll on a planar track.

Abstract: A ramp bridging device having a bridge plate, the rear end of which is pivotably mounted to a ramp about a horizontal transverse shaft, and an extension for rest and support on a platform which is to be loaded or unloaded. The extension is located at the free end of the bridge plate, is movable in the longitudinal direction of the bridge, and can be extended and retracted. Below a continuous cover plate, the bridge plate is provided with longitudinal members which are parallel to one another. The edges of the bridge plate are preferably provided with vertical side plates. Furthermore, the extension is provided with a portion which extends approximately over the width of the bridge and is adapted to rest on the platform. The extension is also provided with longitudinal members which extend parallel to one another.

Abstract: A seal for the gap between the edge of a building opening and the back end of a vehicle driven up to the opening. A covering of flexible material is arranged between a downwardly open U-shaped frame serving to hold the sealing apron on the one hand, and the building or the profiled members fastened thereto on the other hand. For the purpose of being able to quickly assemble and replace this covering, and also for the purpose of being able to balance or equalize stresses within the covering, the edges of the covering are inserted or drawn into longitudinal grooves of the profiled members located on the building and on the U-shaped frame. The edges are folded-over or doubled and surround a core. The edges are located in undercut longitudinal grooves, and in particular in such a manner that sliding movements of these edges are also possible during operational use of the seals.

Abstract: With transfer bridges for ramps having an extension capable of being extended and retracted, and tongues capable of being pushed in, in connection with a bridge plate pivotably mounted on the ramp, a drive is associated with the extension. The drive retracts the extension by a small distance, for instance 20 mm, when the tongues are pushed in and arrested, in order to thus form a gap between the tongues and the vehicle which is to be loaded or unloaded, for avoidance of damage to the vehicle. The retraction of the extension is to occur with the release of the operating button intended for the extension of the extension, or for the lowering of the bridge plate dependent upon a time switch, so that the retraction movement of the extension can occur with a structurally simple double-acting cylinder.

Abstract: A deformable seal of the gap between the edge of a building opening and the back end of a vehicle such as a truck or semi-trailer truck driven up to the building opening. The seal has an apron which at the sides and at the top is fastened to a rigid, downwardly opened U-shaped frame which is spaced from the building. The frame is held by inclined guides which are unchangeable in height at that end thereof facing the building. A flexible covering is provided on both sides as well as at the upper edge of the apron. One edge of this covering is fastened to the frame, and the other edge is fastened to the building. That edge of the covering facing the building is guided in such a way as to be adjustable in height. A tension spring may be provided which is effective on the guides and/or the U-shaped frame in such a manner that the edges of the covering are adjustable upwardly only counter to the effect of this tension spring.

Abstract: A ramp bridging device including a pivotable bridge plate and an extensible extension portion. Stop buffers, pivotable between a vertical operative position and an inoperative position beneath the bridge plate, are provided for protecting the plate and the extension portion. In the operative position, the upper free end of the stop buffers are braced against the bridge plate.

Abstract: A transfer bridge for ramps. The bridge includes a bridge plate, the rear end of which is pivotable about a horizontal axis. The bridge plate is provided with a retractable and extendable extension which in turn is provided with tongues capable of being push-in. The extension is for placement upon the platform to be loaded or unloaded, and the tongues are automatically secured or arrested in the pushed-in condition. A drive, such as a piston, is associated with the tongues, or with the extension carrying the tongues, for retracting the tongues or the extension, subsequent to a pushing-in of the tongues, to form a gap between the tongues on the one hand and the platform (walls) on the other hand.

Abstract: A dock leveler or transfer bridge for ramps, comprising a bridge plate pivotally journalled at its rear end about a horizontal axis on a ramp. The front end of the bridge plate has a foldable or pivotal extension pivoted downwardly in the rest position and, in the working or effective position, pivoted into the plane of the bridge plate. The extension serves for exclusive support of the bridge plate upon the vehicle which is to be loaded or unloaded. When the dock leveler is not being used, the bridge plate is supported upon a pendulum-like strut or support located at the front end thereof. This pendulum-like support, by means of a lever pivotal with the extension, holds or maintains a pivot position for introducing the bridge plate into a ramp recess. In this pivot position, the strut or support cannot correspond or align with its abutment.

Abstract: A transloading bridge for ramps with a bridge plate, the rear end of which is adapted to be pivotally connected to a ramp and the front end of which is provided with an extension adapted to be moved from a retracted position into a moved-out position for resting on a platform to be loaded or unloaded. The extension is also adapted to be moved from its moved-out position into its retracted position. The extension which is located below the bridge plate has longitudinal slots extending in the longitudinal direction of the bridge, while webs serving as reinforcements for the bridge plate extend through the slots and are connected to the bottom side of the bridge plate. Those longitudinal bridge sections of the extension which are separated from each other by the longitudinal slots are reinforced by longitudinally extending additional webs, preferably of U-shape, and are connected to the extension.

Abstract: A closure structure especially for openings in a building, in which a flexible closure member (e.g. a door) is laterally guided in substantially vertical guides and is prevented from accidentally slipping out of the vertical guides by means of latching members, e.g. steel balls, which during the downward movement of the closure member are released through a discharge opening of a magazine into and through a passage in the closure member and into the respective adjacent guide. In response to the upward movement of the closure member, the latching members are returned to the magazine and stored therein. The upward movement of the closure member is brought about by winding the latter up upon a reel, and the downward movement of the closure member is brought about by winding the closure member off the reel.

Abstract: A guiding arrangement for closure bodies such as roller doors, roller gates and shutters, which has a substantially U-shaped cross section for receiving the lateral marginal portions of the closure body by means of which an opening of a building, e.g. a garage entrance, is to be closed. The inside of the guiding arrangement is provided with one or more longitudinal grooves for displaceably receiving a roller mounting system including one or more rollers for laterally engaging and guiding the closure member.