BACKGROUND

The present invention relates to conveyors, and in particular, to extendable conveyors.

In the shipping industry, semi-trailers are used to transport packages, parcels, envelopes, and the like on the ground. Semi-trailers can be backed up to loading docks on buildings for loading and unloading of packages, parcels, envelopes, and the like from the semi-trailer. An extendable conveyor can extend into the semi-trailer and packages can be placed on the extendable conveyor to move the packages into a building.

SUMMARY

A scissor-extend conveyor includes a belt assembly and a belt accumulator assembly. The belt assembly includes an extension and retraction mechanism with scissor linkages that is capable of moving between an extended position and a retracted position, and a belt that wraps around the extension and retraction mechanism. The belt accumulator assembly is configured to accumulate and dispense the belt based on a position of the belt assembly.

A method of extending and retracting a scissor-extend conveyor includes extending an extension and retraction mechanism by expanding scissor linkages of the extension and retraction mechanism. A belt is dispensed from a belt accumulator assembly as the extension and retraction mechanism extends, wherein the belt extends along the extension and retraction mechanism. The extension and retraction mechanism retracts by contracting the scissor linkages of the extension and retraction mechanism. The belt is accumulated in the belt accumulator assembly as the extension and retraction mechanism retracts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a scissor-extend conveyor in a fully extended position.

FIG. 2 is an isometric view of the scissor-extend conveyor in a fully retracted position.

FIG. 3 is an isometric view of an extension and retraction mechanism of the scissor-extend conveyor in a fully extended position.

FIG. 4 is an isometric view of the extension and retraction mechanism of the scissor-extend conveyor in a fully retracted position. FIG. 5 is an isometric view of a portion of the extension and retraction mechanism and an actuator assembly of the scissor-extend conveyor in a fully extended position.

FIG. 6 is an isometric view of a portion of the extension and retraction mechanism and an actuator assembly of the scissor-extend conveyor in a fully retracted position.

FIG. 7 is an isometric view of slide pans on the extension and retraction mechanism of the scissor-extend conveyor in a fully extended position.

FIG. 8 is an isometric view of the slide pans on the extension and retraction mechanism of the scissor-extend conveyor in a fully retracted position.

FIG. 9 is a side view of a belt accumulator assembly of the scissor-extend conveyor in a fully extended position.

FIG. 10 is a side view of the belt accumulator assembly of the scissor-extend conveyor in a partially extended position.

FIG. 11 is a side view of the belt accumulator assembly of the scissor-extend conveyor in a fully retracted position.

FIG. 12 is an isometric view of an extension and retraction mechanism of the scissor-extend conveyor with wheels.

FIG. 13 is an isometric view of the scissor-extend conveyor extending into a semi trailer, wherein a top side, a forward side, and a left-hand side of the semi-trailer are shown as being transparent.

FIG. 14 is a top view of the scissor-extend conveyor extending into the semi trailer, wherein the top side of the semi-trailer is not shown.

FIG. 15 is a side view of the scissor-extend conveyor extending into the semi trailer, wherein the left-hand side of the semi-trailer is not shown.

FIG. 16 is an isometric view of an embodiment of a scissor-extend conveyor with a belt accumulator assembly above the belt assembly extending into a semi-trailer, wherein a top side, a forward side, and a left-hand side of the semi-trailer are shown as being transparent.

FIG. 17 is a top view of the embodiment of the scissor-extend conveyor with a belt accumulator assembly above the belt assembly extending into the semi-trailer, wherein the top side of the semi-trailer is not shown.

FIG. 18 is a side view of the embodiment of the scissor-extend conveyor with a belt accumulator assembly above the belt assembly extending into the semi-trailer, wherein the left-hand side of the semi-trailer is not shown. FIG. 19 is an isometric view of an embodiment of a scissor-extend conveyor with a cantilevered belt assembly extending into a semi-trailer, wherein a top side, a forward side, and a left-hand side of the semi-trailer are shown as being transparent.

FIG. 20 is a top view of the embodiment of the scissor-extend conveyor with a cantilevered belt assembly extending into the semi-trailer, wherein the top side of the semi-trailer is not shown.

FIG. 21 is a side view of the embodiment of the scissor-extend conveyor with a cantilevered belt assembly extending into the semi-trailer, wherein the left-hand side of the semi-trailer is not shown.

DETAILED DESCRIPTION

FIG. 1 is an isometric view of scissor-extend conveyor 100 in a fully extended position. FIG. 2 is an isometric view of scissor-extend conveyor 100 in a fully retracted position. FIG. 3 is an isometric view of extension and retraction mechanism 114 of scissor-extend conveyor 100 in a fully extended position. FIG. 4 is an isometric view of extension and retraction mechanism 114 of scissor-extend conveyor 100 in a fully retracted position. FIG. 5 is an isometric view of a portion of extension and retraction mechanism 114 and actuator assembly 134 of scissor-extend conveyor 100 in a fully extended position. FIG. 6 is an isometric view of a portion of the extension and retraction mechanism 114 and actuator assembly 134 of scissor-extend conveyor 100 in a fully retracted position. FIG. 7 is an isometric view of slide pans 112 on extension and retraction mechanism 114 of scissor-extend conveyor 100 in a fully extended position. FIG. 8 is an isometric view of slide pans 112 on extension and retraction mechanism 114 of scissor-extend conveyor 100 in a fully retracted position. FIG. 9 is a side view of belt accumulator assembly 104 of scissor-extend conveyor 100 in a fully extended position. FIG. 10 is a side view of belt accumulator assembly 104 of scissor-extend conveyor 100 in a partially extended position. FIG. 11 is a side view of belt accumulator assembly 104 of scissor-extend conveyor 100 in a fully retracted position.

Scissor-extend conveyor 100 includes belt assembly 102 (shown in FIGS. 1-11) and belt accumulator assembly 104 (shown in FIGS. 1-4 and 7-11). Scissor-extend conveyor 100 includes forward end 106 (shown in FIGS. 1-4, 7-8, and 11) and base end 108 (shown in FIGS. 1-11). Belt assembly 102 has forward end 106A (shown in FIGS. 1- 4, 7-8, and 11) and base end 108A (shown in FIGS. 1-11). Belt assembly 102 includes belt 110 (shown in FIGS. 1-2 and 9-11), slide pans 112 (shown in FIGS. 2 and 7-8), and extension and retraction mechanism 114 (shown in FIGS. 1-11). Extension and retraction mechanism 114 includes scissor linkages 116 (shown in FIGS. 1-8), left-hand pivot points 118 (shown in FIGS. 3-8), right-hand pivot points 120 (shown in FIGS. 3-8), center pivot points 122 (shown in FIGS. 3-6), axle assemblies 124 (shown in FIGS. 1, 3, and 5), axle rollers 126 (shown in FIG. 5), skids 128 (shown in FIGS. 1-5 and 6-11), forward idler dram 130 (shown in FIGS. 1-4, 7-8, and 11), motorized drum pulley 132 (shown in FIGS. 3-11), and actuator assembly 134 (shown in FIGS. 5-6). Belt accumulator assembly 104 has forward end 106B (shown in FIGS. 1-4 and 7-11) and base end 108B (shown in FIGS. 1-4 and 7-11). Belt accumulator assembly 104 includes vertical stmts 140 (shown in FIGS. 1-4 and 7-11), plate assemblies 142 (shown in FIGS. 1-4 and 7-11), top plates 144 (shown in FIGS. 1-4 and 7-11), left-hand brackets 146 (shown in FIGS. 1-4 and 7- 11), right-hand brackets 148 (shown in FIG. 3), left-hand side wall 150 (shown in FIGS. 1-4 and 7-11), right-hand side wall 152 (shown in FIGS. 1-4 and 7-11), left-hand tracks 154 (shown in FIGS. 1-4 and 7-11), right-hand tracks 156 (shown in FIGS. 1-4 and 7-11), fixed idler drams 158 (shown in FIG. 4 and 9-11), and movable idler drums 160 (shown in FIGS. 9-11). Left-hand side wall 150 is shown as being transparent in FIGS. 9-11.

Scissor-extend conveyor 100 includes belt assembly 102 and belt accumulator assembly 104. Belt assembly 102 is positioned on and connected to belt accumulator assembly 104. Belt assembly 102 is capable of being moved between a fully extended position, as shown in FIG. 1, and a fully retracted position, as shown in FIG. 2. Scissor- extend conveyor 100 has forward end 106 and base end 108 positioned opposite of forward end 106.

Belt assembly 102 has forward end 106A and base end 108A. Forward end 106A is positioned adjacent to belt accumulator assembly 104 when scissor-extend conveyor 100 is in a fully retracted position, as shown in FIG. 2. Forward end 106A is positioned away from belt accumulator assembly 104 when scissor-extend conveyor 100 is in a fully extended position, as shown in FIG. 1. Belt assembly 102 includes belt 110, slide pans 112, and extension and retraction mechanism 114. Belt 110 slides on top of slide pans 112, which are positioned on a top side of extension and retraction mechanism 114.

FIGS. 3-4 show scissor-extend conveyor 100 without belt 110 or slide pans 112 to show extension and retraction mechanism 114 in greater detail. FIGS. 5-6 also show a portion of extension and retraction mechanism 114 in greater detail. Extension and retraction mechanism 114 forms a support structure for belt assembly 102. Extension and retraction mechanism 114 extends from forward end 106A to base end 108A of belt assembly 102. Extension and retraction mechanism 114 includes scissor linkages H6that are connected to one another at left-hand pivot points 118, right-hand pivot points 120, and center pivot points 122. Each scissor linkage 116 is connected to three other scissor linkages 116 - one at left-hand pivot points 118, one at right-hand pivot points 120, and one at center pivot points 122. Scissor linkages 116 are arranged so that a pair of scissor linkages 116 form an X shape and the pair of scissor linkages 116 are connected to one another at center pivot point 122. Each pair of scissor linkages 116 that are arranged in an X shape are then connected to adjacent pairs of scissor linkages 116 at left-hand pivot points 118 and right-hand pivot points 120. Scissor linkages 116 can be moved with respect to one another at left-hand pivot points 118, right-hand pivot points 120, and center pivot points 122. This allows extension and retraction mechanism 114 to move between a fully extended position, as shown in FIG. 3, and a fully retracted position, as shown in FIG. 4. In the fully extended position, scissor linkages 116 extend away from one another at left-hand pivot points 118, right-hand pivot points 120, and center pivot points 122. In the fully retracted position, scissor linkages 116 are collapsed and positioned adjacent to one another.

Extension and retraction mechanism 114 further includes axle assemblies 124, axle rollers 126, and skids 128. Axle assemblies 124, axle rollers 126, and skids 128 are shown in detail in FIG. 5. Axle assemblies 124 are support members that extend from a first side to a second side of extension and retraction mechanism 114. Axle assemblies 124 are connected to scissor linkages 116 at center pivot points 122, in the embodiment shown in FIG. 5. One axle assembly 124 is connected to each center pivot point 112. In an alternate embodiment, axle assemblies 124 can be connected to left-hand pivot points 118 and right-hand pivot points 120 of scissor linkages 116 by means of a slotted connection to allow for lateral movement of the scissor link pivot points. Axle assemblies 124 include axle rollers 126 positioned on a bottom side of axle assemblies 124. Each axle assembly 124 includes one axle roller 126 positioned on a bottom side of axle assembly 124 that extends from a first side to a second side of axle assembly 124. Axle assemblies 124 further include skids 128 positioned on the first side and the second side of axle assemblies 124. One skid 128 is positioned on the first side of each axle assembly 124, and one skid 128 is positioned on the second side of each axle assembly 124.

Extension and retraction mechanism 114 further includes forward idler drum 130 (shown in FIGS. 3-4), motorized drum pulley 132 (shown in FIGS. 3-6), and actuator assembly 134 (shown in FIGS. 5-6). Actuator assembly 134 is not shown in FIGS. 3-4 for clarity, but actuator assembly 134 connects scissor linkages 116 to motorized drum puller 132, as shown in FIGS. 5-6. Forward idler drum 130 is positioned at forward end 106A of belt assembly 102. Scissor linkages 116 that are positioned at forward end 106A of belt assembly 102 are connected to forward idler drum 130. Motorized drum pulley 132 and actuator assembly 134 are positioned at base end 108A of belt assembly 102. As shown in FIGS. 5-6, actuator assembly 134 is connected to motorized dram pulley 132. Scissor linkages 116 that are positioned at base end 108A of belt assembly 102 are connected to actuator assembly 134.

FIGS. 7-8 show scissor-extend conveyor 100 without belt 110 to show slides pans 112 in greater detail. Slide pans 112 are positioned on extension and retraction mechanism 114. Slide pans 112 are connected to scissor linkages 116 at left-hand pivot points 118 and right-hand pivot points 120. One slide pan 112 is connected to opposing left-hand pivot points 118 and right-hand pivot points 120. Slide pan 112F adjacent forward end 106A and slide pan 112B adjacent base end 108A are bigger than the other slide pans 112. As shown in FIG. 7, when belt assembly 102 is in the fully extended position, slide pans 112 slightly overlap one another. As shown in FIG. 8, when belt assembly 102 is in the fully retracted positioned, slide pans 112 almost fully overlap one another.

As shown in FIGS. 1-2, belt 110 of belt assembly 102 extends across a top of slide pans 112 of belt assembly 102 from forward end 106A to base end 108A. Belt 110 wraps around forward idler drum 130 at forward end 106A of belt assembly 102 and extends underneath extension and retraction mechanism 114 back towards base end 108A. Belt 110 extends across axle rollers 126 on axle assemblies 124 underneath extension and retraction mechanism 114. Belt 110 extends around motorized drum pulley 132 at base end 108A and through belt accumulator assembly 104.

Belt accumulator assembly 104 has forward end 106B and base end 108B. Belt accumulator assembly 104 includes vertical stmts 140. Vertical struts 140 are telescoping stmts. An actuator positioned inside of vertical stmts 140 can actuate vertical stmts 140 up and down to adjust the height of vertical stmts 140. There are two vertical stmts on the left-hand side of belt accumulator assembly 104 and two vertical struts on the right- hand side of belt accumulator assembly 104. A first end of each vertical stmt 140 is positioned on the ground and provides support for belt accumulator assembly 104.

Belt accumulator assembly 104 also includes plate assemblies 142. Plate assemblies 142 include top plates 144, left-hand brackets 146, and right-hand brackets 148. Each plate assembly 142 has one top plate 144 that extends from a left-hand side to a right-hand side of belt accumulator assembly 104. Left-hand brackets 146 extend from a left-hand side of top plate 144, and right-hand brackets 148 extend from a right-hand side of top plate 144. Belt accumulator assembly 104 includes four plate assemblies 142 in the embodiment shown in FIGS. 1-11, but can include any number of plate assemblies 142 in alternate embodiments. A second end of vertical struts 140 are connected to either left-hand brackets 146 or right-hand brackets 148 of plate assemblies 142

Belt accumulator assembly 104 further includes left-hand side wall 150 and right- hand side wall 152. Left-hand side wall 150 is positioned on a left-hand side of belt accumulator assembly 104, and right-hand side wall 152 is positioned on a right-hand side of belt accumulator assembly 104. Left-hand side wall 150 is connected to left-hand brackets 146 of plate assemblies 142. Right-hand side wall 152 is connected to right- hand brackets 148 of plate assemblies 142. Top plates 144 of plate assemblies 142 extend from left-hand side wall 150 to right-hand side wall 152, thus plate assemblies 142 connect left-hand side wall 150 to right-hand side wall 152.

Belt accumulator assembly 104 additionally includes left-hand tracks 154 and right-hand tracks 156. Left-hand tracks 154 are shown in FIGS. 1-4 and 7-11. Right- hand tracks 156 are shown in FIGS. 1-4 and 7-8. Left-hand tracks 154 extend across left-hand side wall 150 from forward end 106B to base end 108B. Right-hand tracks 156 extend across right-hand side wall 152 from forward end 106B to base end 108B. There are four left-hand tracks 154 and four right-hand tracks 156 in the embodiment shown in FIGS. 1-11, but any number of left-hand tracks 154 and right-hand tracks 156 can be used in alternate embodiments. The number of left-hand tracks 154 and right-hand tracks 156 can vary depending on the length of belt accumulator assembly 104 and the length of belt 110.

Belt accumulator assembly 104 further includes fixed idler drams 158 and movable idler drams 160. Fixed idler drams 158 are shown in FIGS. 9-11. Movable idler drums 160 are shown in FIGS. 2, 4, and 8-11. Fixed idler drams 158 extend between and connect left-hand side wall 150 to right-hand side wall 152. Fixed idler drums 158 are positioned adjacent to base end 108B of belt accumulator assembly 104. There are five fixed idler drams 158, including fixed idler drums 158A, 158B, 158C, 158D, and 158E, in the embodiment shown in FIGS. 1-11. There can be any number of fixed idler drums 158 in alternate embodiments. Movable idler drams 160 extend between left-hand side wall 150 and right-hand side wall 152. Left sides of movable idler drums 160 are positioned in left-hand tracks 154 and right sides of movable idler drums 160 are positioned in right-hand tracks 156. Movable idler drums 160 move along left- hand tracks 154 and right-hand tracks 156 to move between forward end 106B and base end 108B of belt accumulator assembly 104. There are four movable idler drums 160, including movable idler drums 160A, 160B, 160C, and 160D, in the embodiment shown in FIGS. 1-11. There can be any number of movable idler drums 160 in alternate embodiments.

Belt 110 can be accumulated in and dispensed from belt accumulator assembly 104 as belt assembly 102 moves between a retracted and extended position. Arrows A-K are shown in FIGS. 9-11 to show the path of belt 110 in belt accumulator assembly 104. Belt 110 extends along a top of belt assembly 102 towards base end 108B of belt accumulator assembly 104 and wraps around motorized drum pulley 132, as shown by arrows A. Belt 110 then extends downwards and wraps around fixed idler drum 158A, as shown by arrows B. Belt 110 then extends towards forward end 106B of belt accumulator assembly 104 and wraps around movable idler drum 160A, as shown by arrows C. Belt 110 then extends towards base end 108B of belt accumulator assembly 104 and wraps around fixed idler drum 158B, as shown by arrows D. Belt 110 then extends towards forward end 106B of belt accumulator assembly 104 and wraps around movable idler drum 160B, as shown by arrows E. Belt 110 then extends towards base end 108B of belt accumulator assembly 104 and wraps around fixed idler drum 158C, as shown by arrows F. Belt 110 then extends towards forward end 106B of belt accumulator assembly 104 and wraps around movable idler drum 160C, as shown by arrows G. Belt 110 then extends towards base end 108B of belt accumulator assembly 104 and wraps around fixed idler drum 158D, as shown by arrows H. Belt 110 then extends towards forward end 106B of belt accumulator assembly 104 and wraps around movable idler drum 160D, as shown by arrows I. Belt 110 then extends towards base end 108B of belt accumulator assembly 104 and wraps around fixed idler drum 158E, as shown by arrows J. Belt 110 then extends underneath belt assembly 102 towards forward end 106A of belt assembly 102 and wraps around forward idler drum 130, as shown by arrows K.

As shown in FIG. 9, when belt assembly 102 is fully extended, movable idler drums 160 are positioned near fixed idler drums 158 near base end 108B of belt accumulator assembly 104. In the fully extended position, most of belt 110 extends along belt assembly 102. As shown in FIG. 10, when belt assembly 102 is in a partially extended position, movable idler drums 160 are positioned between forward end 106B and base end 108B of belt accumulator assembly 104. In the partially extended position, a portion of belt 110 extends along belt assembly 102 and a portion of belt 110 is accumulated in belt accumulator assembly 104. As shown in FIG. 11, when belt assembly 102 is in a fully retracted position, movable idler drums 160 are positioned near forward end 106B of belt accumulator assembly 104. In the fully retracted position, most of belt 110 is accumulated in belt accumulator assembly 104.

Movable idler drums 160 move through belt accumulator assembly 104 as belt 110 is accumulated and dispensed. As belt 110 is accumulated in belt accumulator assembly 104, belt 110 will be put under tension with long-stroke air cylinders that are being supplied with air through an adjustable air pressure regulator valve. An air cylinder (not shown in the figures) is attached to each end of a shaft on each movable idler drum 160. The air cylinders each have a first end that is connected to an end of the shaft on each movable idler drums 160 and a second end that is attached to belt accumulator assembly 104. The air cylinders are positioned parallel to the direction of movement of movable idler drums 160. When air pressure is applied to the air cylinders, a force will be applied to the shafts of movable idler drums 160 and subsequent belt tension will occur depending on the air pressure setting of the adjustable air pressure regulator valve.

Scissor-extend conveyor 100 conveys materials from forward end 106 to base end 108. The materials are placed on top of belt 110 at any point along belt 110 and ride on belt 110 until the materials translate off at base end 108A of belt assembly 102 or are taken off of belt 110 by other means. Belt 110 is a continuous belt and travels on top of extension and retraction mechanism 114 and slide pans 112 moving from forward end 106A to base end 108A of belt assembly 102. The return portion of belt 110 travels underneath extension and retraction mechanism 114 while being supported by axle rollers 126 to prevent belt 110 from sliding on the floor. Scissor-extend conveyor 100 can also convey material from base end 108 to forward end 106.

The length of scissor-extend conveyor 100 can be extended or retracted, and this extension and retraction can occur in a continuous manner due to the nature of extension and retraction mechanism 114. The extension or retraction is accomplished by a series of connected scissor linkages 116. The series of scissor linkages 116 are anchored at base end 108 of scissor-extend conveyor 100 by actuator assembly 134. The series of scissor linkages 116 operate substantially in one plane. In the case of a horizontal conveyor, the series of scissor linkages 116 operate in a horizontal plane; in the case of a vertical conveyor, the series of scissor linkages 116 operate in a vertical plane. The scissor- extend conveyor 100 can be set-up to convey materials in any orientation from horizontal to vertical.

Weight-carrying capability of the materials on belt 110 can be through direct- transfer to a supporting structure, such as a floor of a building or a floor of a semi-trailer, or in a cantilevered mode. Direct weight transfer to the supporting structure is accomplished with axle assemblies 124, which are each fastened to one center pivot point 122 of each pair of scissor linkages 116. The ends of each axle assembly 124 have skids 128 that are in direct contact with the supporting structure, such as the floor of the building or the floor of a semi-trailer. On the top of scissor linkages 116 are slide pans 112 and each slide pan 112 is connected to one left-hand pivot point 118 and one right- hand pivot point 120 of scissor linkages 116. Slide pans 112 overlap one another such that one slide pan 112 toward forward end 106 overlaps the next slide pan 112 toward base end 108 of scissor-extend conveyor 100. This is done so belt 110 on the top side of scissor-extend conveyor 100 will be more fully supported, and belt 110 will slide over the base end edge of each slide pan 112 with reduced chance for wear and snagging on the edges of slide pans 112. The transfer of material weight carried on top of belt 110 occurs by transferring through belt 110 to slide pans 112, to scissor linkages 116, to axle assemblies 124, and finally to the supporting structure through the skids 128.

In cantilevered mode, no axle assemblies 124 are present, and the extendable portion of scissor-extend conveyor 100 does not come in contact with a supporting structure, such as a floor. The weight, with its resulting shear and bending moment loads, is carried solely by scissor linkages 116. All other functions of scissor-extend conveyor 100 in cantilevered mode are the same as with the direct weight transfer mode.

Left-hand pivot points 118 and right-hand pivot points 120 that connect the ends of scissor linkages 116 may be manufactured with additional radial tolerance. With additional pivot joint tolerance, scissor linkages 116 are able to extend and retract in a curvilinear path with respect to the primary linear axis of extension and retraction. If an external force was applied to the left or right side or top or bottom, or any 3 -dimensional direction thereof, of the extendable portion of scissor-extend conveyor 100, the extendable portion of scissor-extend conveyor 100 would extend or retract in a curvilinear path.

A conventional rubberized-compound belt will tend to de-track if the extending portion of scissor-extend conveyor 100 is not straight; however, a modular belt, which is designed to flex in 3-dimensional directions, would allow for flexing of scissor linkages 116. Traditional guides or sprockets (not shown) designed to work with the modular belt that control the path of the modular belt would prevent the modular belt from de-tracking.

Since extension and retraction mechanism 114 inherently has positive mechanical connections throughout the extendable portion of scissor-extend conveyor 100, scissor- extend conveyor 100 is capable of applying a force at forward end 106 of scissor-extend conveyor 100. The magnitude of the force at forward end 106 of scissor-extend conveyor 100, FE, can be calculated using a free body diagram analysis of each scissor link pair. The ratio of FE to the force applied by the actuator, FACT, will be a function of the scissor link angles and the number of scissor link pairs. The direction of the force will be in the direction of the primary axis of extension of scissor-extend conveyor 100. The force that is capable of being applied at forward end 106 of scissor-extend conveyor 100 can be used to push a gathering head attached to forward end 106 of scissor-extend conveyor through a semi-trailer.

Belt 110 is powered by motorized drum pulley 132 to save space in confined areas. Belt 110 can be operated in the opposite direction by reversing the rotational direction of motorized drum pulley 132. Variable belt speeds are accomplished through the use of a variable frequency drive to control the speed of motorized drum pulley 132.

Scissor-extend conveyor 100 may have the capability to extend to an extended length multiple times its retracted length. Since belt 110 is one continuous belt, base end 108 of scissor-extend conveyor 100 is designed with belt accumulator section 104 located below the main extendable portion of scissor-extend conveyor 100. Belt accumulator section 104 is designed with a series of movable idler drums 160 that translate to accumulate or release belt length. Movable idler drums 160 have a tensioning system (not shown) that maintains the proper belt tension at any position of belt accumulation or release.

Base end 108 of scissor-extend conveyor 100 sits on four vertical stmts 140. Vertical struts 140 are vertically-extendable via a telescoping tube arrangement with an actuator (such as a hydraulic cylinder) mounted on the inside of the telescoping tubes (not shown). The actuators support the vertical weight of base end 108 of scissor-extend conveyor 100. The extension position of vertical stmts 104 can also be individually- controlled to allow for height and attitude adjustments of base end 108 of scissor-extend conveyor 100. Height and attitude adjustments of base end 108 will be necessary to accommodate varying heights of supporting stmctures, i.e. the floor of a semi-trailer can be at different heights depending on type of suspension. FIG. 12 is an isometric view of extension and retraction mechanism 114 of scissor-extend conveyor 100 with wheels 129. Scissor-extend conveyor 100 includes belt assembly 102, which includes slide pans 112, and extension and retraction mechanism 114. Extension and retraction mechanism 114 includes scissor linkages 116, axle assemblies 124, axle rollers 126, and wheels 129.

Scissor-extend conveyor 100 has generally the same structure and design as described above in reference to FIGS. 1-11. However, instead of having skids on either side axle assemblies 124, scissor-extend conveyor 100 has wheels 129 on either side of axle assemblies 124. As shown in FIG. 12, each axle assembly 124 has one wheel 129 on left-hand side and one wheel 129 on the right-hand side. Wheels 129 can be in contact with the supporting structure, such as a floor of a building or a floor of a semi-trailer, to provide support for belt assembly 102.

FIG. 13 is an isometric view of scissor-extend conveyor 100 extending into semi trailer 170, wherein a top side, a forward side, and a left-hand side of semi-trailer 170 are shown as being transparent. FIG. 14 is a top view of scissor-extend conveyor 100 extending into semi-trailer 170, wherein the top side of semi-trailer 170 is not shown. FIG. 15 is a side view of scissor-extend conveyor 100 extending into semi-trailer 170, wherein the left-hand side of semi-trailer 170 is not shown. Scissor-extend conveyor 100 includes belt assembly 102 and belt accumulator assembly 104. Scissor-extend conveyor 100 includes forward end 106 and base end 108. FIGS. 13-15 further show semi -trailer 170, packages 172, and gathering head 174.

FIGS. 13-15 show scissor-extend conveyor 100, which has the same structure and design as described in reference to FIGS. 1-11 above. Scissor-extend conveyor 100 includes belt assembly 102 that is connected to belt accumulator assembly 104. Belt assembly 102 can be extended from and retracted to belt accumulator assembly 104. Scissor-extend conveyor 100 has forward end 106 and base end 108.

Forward end 106 of scissor-extend conveyor 100 can be extended into semi -trailer 170 to collect packages 172 from semi-trailer 170. Gathering head 174 may be mechanically-connected to forward end 106 of scissor-extend conveyor 100 for use in gathering and placing materials on scissor-extend conveyor 100 to be transported to base end 108 of scissor-extend conveyor 100. Gathering head 174 will advance at the same rate and direction of forward end 106 of scissor-extend conveyor 100. Since gathering head 174 is mechanically-connected to forward end 106 of scissor-extend conveyor 100, the force applied at forward end 106 of scissor-extend conveyor 100 will be transmitted directly into gathering head 174, which applies the force, if needed, to the materials being gathered by gathering head 174.

FIG. 16 is an isometric view of scissor-extend conveyor 200 extending into semi trailer 270, wherein a top side, a forward side, and a left-hand side of semi-trailer 270 are shown as being transparent. FIG. 17 is a top view of scissor-extend conveyor 200 extending into semi-trailer 270, wherein the top side of semi-trailer 270 is not shown. FIG. 18 is a side view of scissor-extend conveyor 200 extending into semi-trailer 270, wherein a left-hand side of semi-trailer 270 is not shown. Scissor-extend conveyor 200 includes belt assembly 202, belt accumulator assembly 204, forward end 206, and base end 208. Belt assembly 202 includes belt 210. FIGS. 16-18 further show semi-trailer 270 and gathering head 274.

FIGS. 16-18 show scissor-extend conveyor 200. Scissor-extend conveyor 200 has a similar structure and design as scissor-extend conveyor 100 described in reference to FIGS. 1-11 above. Scissor-extend conveyor 200 includes belt assembly 202 that is connected to belt accumulator assembly 204. Belt assembly 202 can be extended from and retracted to belt accumulator assembly 204. Scissor-extend conveyor 200 has forward end 206 and base end 208.

In the embodiment of scissor-extend conveyor 200 shown in FIGS. 16-18, belt accumulator assembly 204 of scissor-extend conveyor 200 extends upwards from belt assembly 202. The side walls of belt accumulator assembly 204 extend upwards from belt assembly 202. Belt accumulator assembly 204 thus accumulates belt 210 of belt assembly 202 above belt assembly 202.

Forward end 206 of scissor-extend conveyor 200 can be extended into semi -trailer 270 to collect packages from semi-trailer 270. Gathering head 274 may be mechanically- connected to forward end 206 of scissor-extend conveyor 200 for use in gathering and placing materials on scissor-extend conveyor 200 to be transported to base end 208 of scissor-extend conveyor 200. Gathering head 274 will advance at the same rate and direction of forward end 206 of scissor-extend conveyor 200. Since gathering head 274 is mechanically-connected to forward end 206 of scissor-extend conveyor 200, the force applied at forward end 206 of scissor-extend conveyor 200 will be transmitted directly into gathering head 274, which applies the force, if needed, to the materials being gathered by gathering head 274.

FIG. 19 is an isometric view of scissor-extend conveyor 300 with a cantilevered belt assembly 302, wherein a top side, a forward side, and a left-hand side of semi-trailer 370 are shown as being transparent. FIG. 20 is a top view of scissor-extend conveyor 300 with a cantilevered belt assembly 302, wherein the top side of semi-trailer 370 is not shown. FIG. 21 is a side view of scissor-extend conveyor 300 with a cantilevered belt assembly 302, wherein the left-hand side of semi-trailer 370 is not shown. Scissor-extend conveyor 300 includes belt assembly 302, belt accumulator assembly 304, forward end 306, and base end 308. Belt assembly 302 includes belt 310. FIGS. 19-21 further show semi-trailer 370.

FIGS. 19-21 show scissor-extend conveyor 300. Scissor-extend conveyor 300 has a similar structure and design as scissor-extend conveyor 100 described in reference to FIGS. 1-11 above. Scissor-extend conveyor 300 includes belt assembly 302 that is connected to belt accumulator assembly 304. Belt assembly 302 can be extended from and retracted to belt accumulator assembly 304. Scissor-extend conveyor 300 has forward end 306 and base end 308.

In the embodiment of scissor-extend conveyor 300 shown in FIGS. 19-21, belt assembly 302 does not include axle assemblies or skids that slide along the floor of semi trailer 370. Scissor-extend conveyor is cantilevered when it is extended, as belt assembly 302 is not supported at forward end 306 or along belt assembly 302. Belt assembly 302 of scissor-extend conveyor 300 thus does not contact semi-trailer 370 and is not supported by semi-trailer 370. Belt assembly 302 is fully supported by belt accumulator assembly 304.

Forward end 306 of scissor-extend conveyor 300 can be extended into semi -trailer 370 to collect packages from semi-trailer 370. A user can manually unload packages from semi-trailer 370 by placing the packages on scissor-extend conveyor 300. Alternatively, a gathering head can be attached to forward end 306 of scissor-extend conveyor 300 to automatically unload packages.

While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.