WO1996033882A1

WO1996033882A1 - Retractable tarpaulin cover apparatus for open-topped containers such as truck bodies

Info

Publication number: WO1996033882A1
Application number: PCT/US1996/005714
Authority: WO
Inventors: David K. Denyer; Lynn Chenowth
Original assignee: Denyer David K; Lynn Chenowth
Priority date: 1995-04-26
Filing date: 1996-04-24
Publication date: 1996-10-31
Also published as: AU5571996A

Abstract

A retractable cover system for an open container such as a truck or truck trailer body (11) is disclosed. The system includes a cover (40), a plurality of bows (31) to which the cover is attached, an endless cable (53) to move and guide the bows, with the cable passing through and guiding each bow and the ends of the bows sliding along the tops (19) of the sides (14, 15) of the container; a winder pulley (52) for moving the cable (53) and thereby also moving the cover (40) across the open top of the container; and a plurality of support pulleys (44, 45, 46, 47, 48) to support the cable, such that by operation of the winder pulley (52) to operate the cable, the cover is deployed or retracted over the open top of the container. The system may also include a support (56) along which the winder pulley is slidably positioned to control cable tension. The cover may also be segmented, so that individual segments can be readily removed and replaced, or the cover can be lengthened or shortened as desired.

Description

RETRACTABLE TARPAULIN COVER APPARATUS FOR OPEN-TOPPED CONTAINERS SUCH AS TRUCK BODIES

BACKGROUND OF THE INVENTION Field of the Invention:

The present invention relates to a retractable cover system for a open- topped containers such as truck bodies or truck trailer bodies, and, in particular, to a retractable tarpaulin cover that may be operated by manipulation of a single winder pulley and endless cable arrangement to cover such a container.

Description of the Prior Art:

Conventional truck and truck trailer bodies used in the transport of sand, gravel and other cargo of loose material are of an open frame construction whereby the top of the body is open. Such open truck and trailer bodies, also known as tipper trucks or trailers, have obvious disadvantages during unfavorable weather conditions, such as during rain and strong winds, and contribute to a considerable drag on the movement of the truck by the wind resistance of the open frame.

Various attempts have been made in the past to cover the tipper trucks and trailers so as to reduce the drag and protect the cargo. A common approach has been to provide a tarpaulin sheet which can be manually spread across the opening of the tipper trailer and then secured firmly in position by rope or the like. This approach requires considerable manual effort in that the operator must firstly climb onto the tipper body and then pull the tarpaulin across the opening before securing the tarpaulin in position for transport.

The requirement to climb onto the tipper body creates the risk of injury to the operator and, particularly In unfavorable weather conditions, such an operation may prove dangerous.

Also an inexperienced operator may incorrectly secure the cover across the opening and this may lead to the cover lifting off the trailer at high speeds, thereby posing risks to other road users.

Even when a tarpaulin cover Is secured correctly, continuous vibration of the truck or trailer during transportation may cause loosening of the cover so that wind induced flapping results.

While cable operated cover systems have been disclosed in the past, such systems have been unduly complex, requiring multiple cables or specially constructed guide tracks and wheeled bows to move the cover. Such complex systems are prone to mechanical damage and malfunction and require excessive maintenance.

It Is an object of the present Invention to overcome or substantially ameliorate the disadvantages of the prior art.

SUMMARY OF THE INVENTION

According to the invention, there is provided a retractable cover system for a open container having sides, ends and an open top, the retractable cover system comprising: a cover for the open top of the container; a plurality of bows to which the cover is attached spanning the open top and supporting the cover, each bow having guides at its two ends adapted to slide along the tops of the sides of the container when the cover is being moved; an endless cable to which the cover is connected, the cable passing through and guiding each guide of each end of each bow; a winder pulley for controlling the movement of the cable and thereby also controlling the movement of the cover across the open top of the container; and a plurality of support pulleys to support the cable, the arrangement of the support pulleys and endless cable being such that by operation of the winder pulley to operate the cable, the cover is retractably deployed over the open top of the container. The leading edge of the cover is attached to a leading bow, the cable is secured to the leading bow, and movement of the cable causes cooperative movement of the leading bow and deployment or retraction of the cover.

In a preferred form of the Invention, the system includes a means for adjusting the tension of the cable. Preferably, the cable tension adjustment means comprises a support along which the winder pulley is slidably positioned and means for securing the winder pulley at a desired position along the support.

The cover may also be segmented, so that individual segments can be readily removed and replaced, or the cover can be lengthened or shortened as desired. BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood and put Into practical effect, reference will be made to the accompanying drawings, in which:

Figure 1 is a perspective view of a tipper trailer body of the type to which the retractable cover system of the invention may be mounted.

Figure 2 is a partly broken away perspective view of the top of one of the side walls of the trailer body of Figure 1 showing a preferred channel track for the retractable cover system of the invention. Figure 3 Is a partly broken away perspective view of the rear end of the channel track of Figure 2 and an exploded view of a support pulley arrangement connected thereto.

Figure 4 is a perspective view of the underside of a preferred cover for the retractable cover system of the invention. Figure 5 is a perspective view of the front bow of the cover of Figure

4 engaging the front end of the channel track of Figure 2.

Figure 6 Is a side view of a preferred bow end for slidably engaging the cover of Figure 4 to the channel track of Figure 2.

Figure 7 is a perspective view of the cover of Figure 4 being inserted onto an endless cable for the retractable cover system of the invention.

Figure 8 is an elevational view of the top of the outer front wall of the trailer body of Figure 1 showing part of a preferred arrangement of support pulleys for the retractable cover system of the Invention. Figure 9 is a perspective view of a front cover channel being located over the support pulleys shown in Figure 8.

Figure 10 Is a partly broken away elevational view of the outer front wall of the trailer body of Figure 1 showing a preferred winder pulley and cable tension adjustment means.

Figure 1 1 is an Isolated perspective view of the preferred arrangement of winder pulley, support pulleys and cable (with attached bows) that control the movement of the cover of Fig. 4 over the top of the trailer body of Figure 1 . Figure 1 2 illustrates the modified cable system on a truck bed, with a rear mounted actuator.

Figure 1 3 is a similar view, but with a side mounted actuator.

Figure 14 is an enlarged perspective view of the rear mounted actuator. Figure 1 5 is a side view of the structure of Figure 14.

Figure 1 6 is a side view of the side mounted actuator.

Figure 1 7 is a top view of the rear portion of a truck bed with the cover almost closed.

Figure 18 is an enlarged sectional view taken on line 18-1 8 of Figure 1 7.

Figure 1 9 is an enlarged sectional view taken on line 1 9- 1 9 of Figure 1 7.

Figure 20 is a sectional view taken on line 20-20 of Figure 1 8. Figure 21 is a view similar to Figure 20, but with the cover on top of the bows.

Figure 22 is a view similar to Figure 1 9, showing the addition of a side overlap cover.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS For simplicity, the invention will be described herein with respect to a typical installation, that on a tipper truck trailer body 1 1 . It will be understood, however, that the cover system of this invention is equally useful with truck mounted open-topped container bodies and with open- topped containers generally, such as skid-mounted containers used for collection of trash, construction refuse, and the like.

The conventional tipper trailer body 1 1 shown in Fig. 1 has a front end wall 1 2, a rear end wall 1 3 and opposed side walls 14 and 1 5 rising from a floor 1 6 and providing an opening 1 7 at the top of the body 1 1 . The tipper mechanism (not shown) for the body 1 1 is housed in the structure 18 formed at the front end of the body 1 1 and is adapted to co-operate with a ram or similar tipping means mounted on the truck (not shown).

As shown In Fig. 2, the upper edge of both of the side walls 14 and 1 5 consists of a hollow closed channel 1 9 that extends the full length of each side wall. Welded or otherwise secured to the top of both of the closed channels 1 9 is an open channel 20, preferably made of aluminum, the opening of which faces horizontally towards the interior of the body 1 1 . The upper surface of the open channel 20, which is horizontal, serves as a track for supporting runner means in the form of bow ends (shown in Fig. 4) for the retractable cover system.

Fig. 3 shows a single support pulley arrangement connected to the channel track 20 adjacent the rear end of both of the side walls 14 and 1 5. The support pulley arrangement of Fig. 3 is adapted to support part of an endless cable 53 to which the cover of the retractable cover system is connected through the bows 31 .

A bolt 21 with a flat cut head 22 is located through a hole 23 in the side wall 24 of the channel track 20. Fitted to the shaft of the bolt 21 that emerges from the hole 23 are, in order, a plurality of spacer washers 25, a pulley wheel 26, a washer 27 and nut 28. The pulley wheel 26 has a circumferential groove 29 into which the endless cable is engaged.

The cover 30 of Fig. 4 is shown upside-down to reveal the framework system of bows 31 that support the cover sheet. Each bow, although substantially hidden by the cover sheet in Fig. 4, may be constructed in the shape of a gradual arch or the angular shape shown in Fig. 5.

At the end of the cover 30 which will be fixed to one end of the container (i.e., commonly the front end of the trailer body) there is a front end bow designated 31 " (to separately identify it among the plurality of bows 31 ), which is shown In Figs. 4 and 5. The front end bow 31 " has end portions 32 and 33 which have holes formed therethrough for locating bolts. The bolts (not shown) secure the front end bow 31 " to the hollow closed channels 1 9 or otherwise to the container body at one of its ends. At the other end of the cover 30, i.e., the end which leads the deployment of the cover 30, is leading bow 31 ' (so designated also to separately identify it) . The attachment of leading bow 31 ' to the cable 53 for deployment or retraction of the cover 30 will be described below. The remaining bows 31 have end portions to which may be secured bow end members of two types as shown in Fig. 4, namely lock-down bow ends 34 and block bow ends 35. The lock-down bow ends 34, shown in detail in Fig. 6, are in the form of a channel section having a main body 36 and a tongue 37. The main body 36 is adapted to slide over the upper surface of the channel tracks 20 and the tongue 37 Is adapted to lock the bow ends 34 into stable engagement with the channel tracks 20 so as to restrict vertical and horizontal movement of the bows.

The block bow ends 35 are similar to the lock-down bow ends 34 but lack a tongue piece, and so are only adapted to slide over the upper surface of the channel tracks 20, The relative number of lock-down bow ends 34 and block bow ends 35 may vary depending on the length of the trailer body and other factors.

Each bow end 34 and 36 has a cylindrical hole 38 formed therethrough such that, when the bow end is engaged against its channel track, the hole 38 has its axis parallel with the channel track 20. The holes 38 are adapted to receive an endless cable 53 therethrough and to be guided by that cable as shown in Fig. 7. The cover sheet 40 shown in Figs. 4 and 7 may have a series of sleeves formed from one long side of the sheet to the other. Each sleeve encloses the main bent part of each bow 31 and has bow end portions projecting out of openings to the sleeve adjacent the long sides of the sheet. Cable ties may be fitted through each sleeve so as to engage around the bow when it is enclosed by the sleeve, thereby securing the cover sheet 40 to the bows. Fig. 4 shows one of the cable ties 41 In its fitted position but prior to tightening around the bow at the rear end of the cover. The cover sheet is of a conventional tarpaulin material, such as polyvinylchloride (PVC), rubber, canvas, and the like, and, as shown in Fig. 7, can be readily folded in accordion fashion or extended as required.

In Fig. 7, the endless cable 42 has cable clamps 43 attached thereto at each end of the series of movable bows 34 and 35. Preferably the cable 42 is a 5 mm steel wire cable, although the choice of size and material for the cable may be made by the user, taking into account the use of the truck trailer or other container and the environment in which it will be used and parked.

Fig. 8 shows five support pulleys 44, 45, 46, 47 and 48 mounted at the top of the outer side of the front end wall 12 of the trailer body. Pulleys 44, 45 and 46 are located on the driver's side of the trailer body. Pulley 44 is mounted at a inclined angle to the vertical (see also Fig. 1 0), but has its axis of rotation inclined in the direction of a vertical plane. Pulley 45 is mounted such that its axis of rotation is vertical and pulley 46 is mounted such that its axis of rotation is horizontal. Pulleys 47 and 48 are mounted such that they share the same vertical axis of rotation.

Pulleys 45 and 47 are at the same height relative to their respective channel tracks 20. Pulley 48 is at a height that corresponds to the location of the holes 38 in the bow ends as they slide over the channel tracks 20. As shown in Fig. 9, the pulleys 44, 45 and 46 are mounted on a channel bracket 49, and pulleys 47 and 48 are mounted on a channel bracket 60. Both channel brackets 49 and 50 are bolted to the front end wall 12, and a front cover channel 51 (shown disassembled from the wall 1 2) Is located over both brackets 49 and 50 for protection of the pulleys 44 to 48. The cover channel 51 may have portions thereof cut out so as not to interfere with the operation of the pulleys or the endless cable.

A winder pulley 52, mounted to the outer side of the front end wall 1 2, is shown in Fig. 10 connected to a cable tension adjustment means. A part of the endless cable 53 la shown engaged between the inclined support pulley 44 and winder pulley 62. The angle of the inclined support pulley 44 is such that the cable 53 follows a line that is tangential to the engaging groove of the winder pulley 52 and is continuous with the plane of the support pulley 44 as shown in Fig. 10. The winder pulley 52 may have a handle 54 for winding and spring locking means 55 that locks the winder pulley 52 when desired. The location of the winder pulley 52 may be slidably positioned along a track 57 formed as a pair of slots in the mounting assembly 56 for the winder pulley 52. The winder pulley 52 may be secured at a desired position along the track 57 by such means as locking bolts and so can adjust the tension of the endless cable 53.

There are two support pulleys 59 and 60 at the upper rear end of the side walls 14 and 1 5 of the trailer body which co-operate with support pulleys 44 to 48 at the upper front end of the trailer body and the winder pulley 52 to engage an endless cable 53 In the manner as shown in Fig. 1 1 . One series of bow ends 34 and 35 is guided by the portion of cable that extends between support pulleys 59 and 47, and another series of blow ends 34 and 35 is guided by the cable portion extending between support pulleys 60 and 45.

Fig. 1 1 shows a preferred arrangement of support pulleys, endless cable and winder pulley. As will be described in more detail below, the cable 53 is made endless by being clamped back on itself at two locations by cable clamps 61 and 62 located on either side of the ends of the leading bow 31 ' . The obstruction caused by these cable clamps will cause the bow 31 ' to move at the same rate as the cable when It Is being wound by the winder pulley 52. Movement of the leading bow 31 ' in a direction towards the rear of the trailer will drag the other movable bows 31 (not Including the front bow 31 ") as far as desired over the top of the body 1 1 , normally all the way to the rear of the trailer until the cover sheet 40 is spread out over the top of the trailer body 1 1 and there is an even distribution of bows 31 .

With this arrangement, the cover may be retractably moved over the top of the trailer body by operation of the winder pulley. The arrows along cable 53 in Fig. 1 1 show the direction of its movement as the bow ends are being moved towards the rear of the trailer so as to extend the cover over the trailer top.

A preferred embodiment of the invention is illustrated beginning at Figure 1 2. In this embodiment, the separate channel 20 is not required and the bow end members ride directly on the top surface 64 of the side walls 14 and 1 5. The cable tracks are illustrated in Figures 1 2 and 1 3, which are substantially identical except for the placement of the winding mechanism, which is on the back 1 3 or side 1 4 of the truck body 1 1 , respectively. In each case an additional pulley 65 or 66, respectively, is included to allow the cable 53 to round the corner of the truck body 1 1 . In order for the cable 53 on each side 14 and 1 5 of the body 1 1 to move in the same direction in unison, the cable 53 crosses itself at 67.

Detailed views of the winding mechanism are shown in Figures 14-1 6. The routing pulleys 44, 45, 46 and 65 (Figure 14) are conveniently mounted on a bracket 68 which can be bolted or welded to the end 1 3 of the truck body 1 1 . The winding pulley 53 with its handle 54 is preferably mounted on a movable block 70 which is seated inside bracket 69 which is mounted on the end 1 3 of the truck body 1 1 . As best illustrated in Figure 1 5, movable block 70 can be adjusted upwardly and downwardly by rotation of bolt 71 . The pivot bolt 72 on which the pulley 52 rotates is seated in a slot 73 in bracket 69, so that by adjustment of bolt 71 , pulley 52 may be moved upwardly or downwardly and the appropriate amount of tension imparted to cable 53. Pulley 52 preferably also has a string loaded pin 74 mounted on it and extending through into a hole or recess 75 in bracket 69, so that the winding mechanism can be locked in place when the cover is positioned at the desired point by the operator. In most cases, this will be with the cover either fully retracted or fully extended, and there will be two respective holes or recesses 75 for those two positions. Other intermediate positions may also be designated by additional holes or recesses 75, if desired.

It will be noticed in Figures 14-1 6 that the various pulleys are preferably angled slightly to allow the cable 53 to move without adjacent portions rubbing or chafing against each other, as best seen in Figure 14. Also, the handle 54 may be pivoted on pin 76 if desired, to allow it to be locked in the retracted position 54' when not in use.

The equivalent structure for a side mounted winding unit is illustrated in Figure 1 6, where the pulleys 44 and 46 are mounted on bracket 77. Also if desired, a guide can be mounted on the back 1 3 of the truck to assist in separation of the adjacent cable tracks. The movement of the cover 30 in this embodiment is illustrated in

Figures 17-1 9. Each bow 31 other than leading bow 31 ' is attached to bow slides 84. Leading bow 31 ' is attached to bow slides 78 and 79, which as described below are of a different shape than slides 84. All slides ride on the top 64 of sides 14 and 1 5, respectively. A slight separation is shown in Figures 1 8 and 1 9, partially for clarity, and partially to indicate that wind lift or cable tension may at times lift the slide 78, 79 or 84 off the top 64 slightly, but because of the guiding and restraint of cable 53, that is of no consequence. For the leading bow 31 ', each slide 78 and 79 (as illustrated in Figure 1 8) has two openings for the passage of different sections of cable 53. In the lower section, the cable 53 merely passes through a slot 80 in the slide 78, in which idler pulleys 81 may be mounted on axles 82 to guide the cable 53. The cable 53 at this point is merely passing through the slide and is guiding but not exerting any pulling force. At the upper portion however, the cable (here designated 53') is secured at the front and back of the slide 78 by clamps 61 and 62 so that, as described above, as the cable moves forward and backward along the sides of the truck body 1 1 , the clamped portions 53 simultaneously move the slides 78 and 79 with them, thus moving the leading edge of the cover 30 backwards and forwards across the top of the truck bed 1 1 .

The additional bows 31 to which the cover 30 is secured at desired intervals are mounted on slides 84, as illustrated in Figure 1 9. It will be seen that the cable 53 passes through a hole 85 in the slide 84, so that the cable moves freely and merely serves as a guide for the slide 84, but does not directly move the slide 84. Rather, each side 84 is moved by action of the cover 30 and the leading bow 31 ' . As the cable is moved to deploy the cover 30 from its retracted position at the front of the truck body, the leading bow 31 ' moves rearwardly of the truck body on its slides 78 and 79 which are moved by the cable 53 to which the slides are clamped. As the first portion of the cover sheet 40 becomes fully extended by movement of the front bow 31 , as illustrated in Figure 1 7, the first portion of the cover sheet 40 then exerts a pull on the first support bow 31 which also begins to slide rearwardly on its slides 84, being guided but not pulled by cable 53 positioned through hole 85. As the cover 30 deploys farther so that the second section becomes fully extended, that section begins to exert a pull on the next support bow 31 , which then also begins to move rearwardly, and so forth until all of the support bows move forward and the cover 30 is fully deployed. Of course, there may be partial deployment, if desired.

Retraction of the cover 30 is accomplished in exactly the opposite manner. As the winding mechanism is turned to run the cable 53 forward, the slides 78 and 79 and the leading bow 31 ' are simultaneously moved forwardly and the first section 40 of the flexible cover becomes folded and compressed in the same manner as illustrated in Figure 7 when the remaining bows 31 have not yet moved. When the leading bow 31 ' reaches the position of the first support bow 31 the leading bow and its slides, usually as well as portions of the folded cover, push against the slide 84 and the first bow 31 forcing it forwardly as the leading bow moves in response to the movement of the cable 53. The assembly keeps moving forward in the same manner and each of the deployed bows 31 is picked up and pushed as the moving assembly reaches it, with the intermediate portions 40 of the flexible cover 30 folding out of the way until the entire cover 30 and all the bows are returned to the fully retracted position at the front of the truck body 1 1 .

A preferred form of mounting of the cover 30 in the bows is illustrated in Figures 20 and 21 . Each bow 31 , 31 ' and 31 " is constructed of a hollow cylindrical rod with a longitudinal slot at either the bottom (Figure 20) or the top (Figure 21 ) . The cover 30 is divided into individual segments, here indicated as 40 and 40', each of which has its transverse ends formed into loops 86, each of which has a solid rod 87 inserted there through. Each segment 40 or 40' is then mounted on the respective adjacent bows 31 , 31 ' and/or 31 " by sliding the rods 87 and loops 86 through the respective slots 88 from the ends of the bows. The cover segments 40 and 40' are then retained in place by closing the ends of the hollow bows by plugs 89 which are secured to the slides 78, 79 or 84 by bolts 90. By having the cover 30 segmented and the segments 40 individually mounted in the adjacent bows, repair of a damaged segment is readily facilitated by simply releasing the two bows and sliding out the damaged segment 40 of cover 30 and sliding in a new segment. Similarly, this also allows for simple revision of the length of a particular cover by adding or subtracting intermediate bows 31 with their related cover segments 40'. This is useful, for instance, when a particular cover and bow assembly is to be moved from attachment to one truck body to another truck body which is of different length.

Another advantage of this embodiment of the invention is illustrated in Figure 22, where a side flap 91 is attached to the cover 30 and hangs down over the side 1 5 of the truck body. The side flap 91 is flexible and will be folded or unfolded as the cover moves forwardly or backwardly as described above. The side flap serves to aid in preventing materials being carried in the truck body from being blown or dropped over the side of the truck body. If desired, the side flap 91 can have appendages (not shown) for securing the side flaps to the side of the truck body to further prevent wind lift of the cover, loss of carried materials, or unauthorized access to the interior of the truck body.

It will be evident that various modifications made be made In details of design and construction without departing from the scope or spirit of the invention. The above description is therefore intended to be exemplary only, and the scope of the invention is to be determined by the appended claims.

WE CLAIM:

Claims

1 . A retractable cover system for a open container having sides, ends and an open top, the retractable cover system comprising: a cover for the open top of the container; a plurality of bows to which the cover is attached spanning the open top and supporting the cover, each bow having guides at its two ends, each of the guides adapted to slide along the tops of the sides of the container when the cover is being moved; an endless cable to which the cover is connected, the cable passing through and guiding each guide of each end of each bow; a winder pulley for controlling the movement of the cable and thereby also controlling the movement of the cover across the open top of the container; and a plurality of support pulleys to support the cable, the arrangement of the support pulleys and endless cable being such that by operation of the winder pulley to operate the cable, the cover is retractably deployed over the open top of the container.

2. The retractable cover system of Claim 1 further including means for adjusting the tension of the cable.

3. The retractable cover system of claim 2 wherein the cable tension adjustment means comprises a track along which the winder pulley is slidably positioned and means for securing the winder pulley at a desired position along the track.

4. The retractable cover system of Claim 2 wherein the cable tension adjustment means comprises the winder pulley being mounted on a movable base, whereby movement of the base causes the winder pulley to exert tension on the cable.

5. The retractable cover system of Claim 1 wherein the cover has a leading edge which is attached to a leading bow, the cable is secured to the leading bow, and movement of the cable causes cooperative movement of the leading bow and deployment or retraction of the cover.

6. The retractable cover system of Claim 1 wherein a channel is mounted on top of the sides of the container and wherein at least a portion of the guides are adapted to extend into and follow the channel when the cover is being moved.

7. The retractable cover system of Claim 1 wherein movement of the leading bow and leading edge of the cover in response to movement of the cable causes sequential movement of each of the other bows and remaining portion of the cover.

8. The retractable cover system of Claim 1 wherein the cover is segmented and each segment is removably attached to two adjacent bows.

9. The retractable cover system of Claim 8 wherein individual segments with associated support bows can be added to or removed from the cover system to alter the extended length of the cover.

10. The retractable cover system of Claim 1 wherein the winding pulley is mounted on one side of the container.

1 1 . The retractable cover system of Claim 1 wherein the winding pulley is mounted on one end of the container.

1 2. The retractable cover system of Claim 1 wherein the container comprises the body of a truck.

1 3. The retractable cover system of Claim 1 wherein the container comprises the body of a truck trailer.