Slidable truck cover assembly

Abstract: A tarpaulin 28 for covering the top of a dump truck body is attached at intervals to slats 103 which are carried by support platforms 105 resting on the top edges of opposite side walls 14 of the truck body. The slats are slidable along the top of the truck body by cables 125 attached to the platforms 105. Side portions 111 of the tarpaulin are held by downwardly extending end portions 115 of the slats to lie close to the side walls 14 of the truck body.

Description: This invention relates to a tarpaulin support apparatus for trucks and in particular to an apparatus which allows a tarpaulin cover to be mechanically drawn or withdrawn from the top portion of the truck bed. The use of truck covering has long been recognized as a necessity for trucks. It is particularly true in dump trucks carrying loose sand, gravel, stones and the like. In particular, trucks carrying asphalt are frequently required by law to be appropriately covered. U.S. Patent Specification No. 4 725 090 describes a tarpaulin support apparatus for supporting a tarpaulin over a bed of a truck comprising a slat having a central portion that extends between a first side wall of the truck and a second side wall of the truck, a first end portion extending from the end of the central portion downwardly over and adjacent to the first side wall of the truck, and a second end portion extending from the other end of the central portion downwardly over and adjacent to the second side wall of the truck, slat support means for supporting the slat on the side walls of the truck, and attachment means for attaching the tarpaulin to the slat. The present invention is characterized in that the slat support means includes a first slat support platform mounted on the first end portion of the slat, the first slat support platform having a bottom wall adapted to rest on and to slide on the top of the first side wall of the truck, and a second slat support platform mounted on the second end portion of the slat, the second slat support platform having a bottom wall adapted to rest on and to slide on the top of the second side wall of the truck. A preferred apparatus in accordance with the invention for mechanically covering and uncovering the bed of a truck will completely enclose and cover the truck bed area allowing no opening. The advantages and features of the apparatus are that it reduces driver fatigue in covering the truck bed and also reduces risk of injury considerably. The driver can place the tarpaulin over the load in the truck bed by turning a hand crank placed near the cab door. Turning the crank in one direction moves the tarpaulin over the load. Turning the crank in the reverse direction removes the tarpaulin from over the load. The device will fit most dump trucks on the market today. One advantage is that it is not over-width (96 inches). The system works similarly to a curtain rod. It has a support member on each side, which is also used as a guide rail for tarpaulin supports to slide on. It has a pulley on each end of the guide rail and a cable is attached around the two pulleys - one assembly on each side of the truck bed. The cable runs through a number of wooden slats (the actual number depends on the length of the truck bed). The slats have holes drilled near the ends to allow the cable to slide freely through them. The rear most slat is attached to the cable so when the cable is moved in either direction the slat moves with it. With the attached slat to the rear of the truck, the remainder of the slats are spaced about two feet apart - between the front pulleys and the rear most slat. The tarpaulin being presized for the truck, is fastened at the front end near or in line with the front cable pulleys. It is spread over the slats and fastened to the prespaced slats. The slats have a small metal device attached to the end allowing the tarpaulin to come down over the sides of the truck bed 4 to 6 inches to completely cover the truck bed. With tarpaulin in place and fastened, it simply covers or uncovers the load by rotating the cable. The cable assembly is rotated by a simple chain drive assembly. The two front cable pulleys are attached rigidly to a cross shaft. On this shaft is attached a chain sprocket. Near the left hand door of the truck cab is attached another sprocket of the same size as the one on the tarpaulin cross shaft. The sprocket is attached under the cab shield by the front of the truck bed by means of a pair of bearings - short shaft - and a fabricated bracket. The two sprockets are connected with a suitable roller chain. A hand crank handle is fashioned to fit over the drive sprocket shaft. The crank handle is designed so it is removable when not in use, thus not sticking out beyond legal width of truck bed. The crank shaft has a simple locking device to prevent tarpaulin moving from forward or rear position until unlocking of shaft allowing it to turn. It should be noted that the tarpaulin extends over the sides of the truck to completely enclose the covered contents. An important feature of this invention is that the tarpaulin covers and seals or encloses the top portion of the side walls, front and rear walls of the truck bed when in the extended covering position. This is done by securing the sides of the tarpaulin to L-shaped tarpaulin supports attached to the end of each slat. These tarpaulin supports extend downwardly over the sides of the truck bed and hold the tarpaulin over the truck bed. A cable tension adjusting mechanism is provided which will easily and simply vary the tension of the operating cables of the device. Driver fatigue and injuries are reduced by allowing the manipulation of the device from near the truck cab. The truck covering device is installable on most trucks, so that all lateral operating mechanisms are completely covered by the truck frame and body. The invention will be described in more detail by way of example, with reference to the drawings in which: Figure 1 is a perspective view of a dump truck upon which has been installed a tarpaulin support apparatus in accordance with the present invention. Figure 2 is a perspective view taken along line 2-2 of Figure 1. Figure 3 is a perspective view taken along line 3-3 of Figure 1. Figure 4 is a view taken along line 4-4 of Figure 2. Figure 5 is a lateral view of Figure 4. Figure 6 is a view taken along line 6-6 of Figure 2. Figure 7 is a view taken along line 7-7 of Figure 2. Figure 8 is a cross-sectional view taken along line 8-8 of Figure 3. Figure 9 is a top view taken along line 9-9 of Figure 3. Figure 10 is a detail perspective view of the mounting of one of the slats supporting the cover, and Figure 11 shows part of Figure 10 on an enlarged scale. Figure 12 is a lateral view taken along line 12-12 of Figure 1 showing tarpaulin cover attached to the cab shield. Figure 13 is a lateral view taken along line 13-13 of Figure 1 showing attachment of the stationary tarpaulin cover on the rear of the truck bed. Figure 14 is a lateral view of the optional electrical drive system which may be utilized in place of the hand crank system. DETAILED DESCRIPTION Referring to the drawings and in particular to Figure 1, 10 represents a conventional dump truck having a bed 12 with two side walls 14, a rear wall 16 and a front wall 18. A cab shield 20 extends from the front wall 18 to partially cover the truck cab roof 22. Two hollow lateral support members 24 extend from the cab shield 20 along the top portion of the side walls 14 to the rear wall 16. A plurality of slats 26 extends transversely between the lateral support members 24. These are covered and attached to a flexible tarpaulin 28 by means of screws extending through the tarpaulin 28 and into the slats 26. A plurality of L-shaped lateral tarpaulin supports 32 are attached to each end portion of each slat 26 by bolts 36 and extend downwardly over the edge of hollow lateral support members 24. Tarpaulin 28 is attached to the end portion of lateral tarpaulin supports 32 by means of lateral bolts 34 extending through both lateral tarpaulin support 32 and tarpaulin 28. Tarpaulin 28 also extends from the cab shield 20 to the rear wall 16, supported by slats 26 positioned at about two foot intervals along the support members 24. Tarpaulin 28 in attached to cab shield 20 by clamp member 21, as shown in Figure 12, which extends the width of the cab shield 20. Clamp bolts 23 extend through tarpaulin 28, clamp member 21 and into cab shield 20 to clamp tarpaulin 28. Thus in its extended phase, the tarpaulin 28 extends completely over the top of truck bed 12 and over the side of the side walls 14 to completely enclose the contents of bed 12. As may be seen, L-shaped lateral tarpaulin supports 32 extend over the top of tarpaulin 28, over the sides of hollow lateral support members 24 and are secured to slats 26 by means of bolts 36. Referring to Figures 1 and 13, a channel member 27 welded to each side wall 14, extends across the bed 12. Rear retaining member 31 (usually wood) is bolted to channel member 27 by bolts 29. Stationary tarpaulin cover 35 (Figure 13) extends from retaining member 31 to the outer portion of rear wall 16 where it is bolted by rear wall bolts 41 which pass through a transverse rear retaining strip 43 and into rear wall 16. The other end portion of stationary tarpaulin cover 35 is transversely bolted to retaining member 31 through a top retaining strip 45 which extends across the truck bed 12. When the tarpaulin 28 is in its extended position, rear slat 60 and tarpaulin 28 extend over rear retaining member 31 and stationary tarpaulin cover 35, thus sealing or shielding the rear portion of bed 12 from the outside. Likewise the front portion of tarpaulin cover 28 is clamped to cab shield 20 sealing or shielding the front portion of bed 12 from the outside. Hence, in its extended position tarpaulin 28 completely seals or encloses bed 12 on the front, rear and sides. The mechanism for extending and retracting the tarpaulin 28 is as follows: Referring to Figures 2, 6, 7, 8 and 9, two forward pulleys 38 connected by a hollow shaft 40 are attached to lateral portions of cab shield 20 by means of forward pulley brackets 42. Forward pulleys 38 are attached to a short shaft 44 extending through a bearing 46 and attached to hollow shaft 40 by means of a shaft pin 48 which extends through hollow shaft 40 and short shaft 44. As shown in Figures 3, 8, and 9, rear pulleys 50 are attached to either side of the rear portion of hollow lateral support members 24 by means of brackets 52. Rear pulleys 50 are attached to rear brackets 52 by means of rear bearing bolt 56 extending through rear bearing 54 within rear pulley 50. A looped cable 58 (Figs. 9 and 13) extends ground forward pulleys 38 and rear pulleys 50 in a loop-like fashion and are attached to rear slats 60 by means of threaded rods 62 and nut 63. Threaded rods 62 are hollowed out, the ends of cable 58 inserted and sweat welded together. Threaded rods 62 then extend through rear slat 60. Nut 63 is screwed on threaded rod 62 to bear against rear slat 60 and tighten cable 58. The tensions on cable 58 may be varied by turning nuts 63. The upper loop of cable 58 extends through each slat 26 around forward pulley 38 and rear pulley 50 and through hollow lateral support members 24. As may be seen, the tension on the cables 58 may be adjusted by adjusting the nut 63 positioned on threaded rod 62. It should be noted that forward pulleys 38 and rear pulleys 50 are fully contained within the lateral truck frame and do not extend laterally therefrom. This has distinct advantage in lessening damage to these pulleys and also contains the pulleys within the legal width of the truck which is regulated frequently by state law. Pennsylvania state law requires the truck width to be no more than 96 inches. The forward and rearward movement of the tarpaulin 28 over the top of the truck bed 12 is controlled by a hand crank device 64 (Figures 2, 4, 5 and 6), and is mounted upon the forward position of front wall 18 by means of mounting bracket 66. A crank shaft 68 extends through two bearings 70 which are attached to mounting bracket 66. A chain sprocket 72 is positioned on crank shift 68 between bearings 70. Removable hand crank 74 has a hollow tube portion 75 attached which slides easily over the end portion of crank shaft 68. Notches 77 in the end of tubs portion 75 engage a permanent shaft pin 76 which extends outwardly from crank shaft 68. Thus the hand crank can be inserted on crank shaft 68 to engage shaft pin 76 and turn the crank shaft 68. Upon completion of use, the hand crank 74 is completely removed so as not to protrude laterally from the side of the truck 10. As shown in Figures 2 and 6, a looped chain 78 extends about the chain sprocket 72 and about an axle sprocket 80 positioned on short shaft 44. As may be seen, when the hand crank 74 rotates chain sprocket 72, chain 78 will rotate axle sprocket 80 and hollow shaft 40. Cables 58 will then cause rear slat 60 to extend or retract the tarpaulin 28. Alternatively, an electric motor 82 may be substituted for hand crank device 64 (Figure 14). Electric motor 82 is of a reversible type which may be activated by motor switches (not shown) to extend or retract the tarpaulin 28 as did the hand crank device 64. Electric motor 82 has a motor sprocket 84 and motor chain 86 connected to an auxiliary sprocket 88 upon crank shaft 68. In operation either hand crank 74 or electric motor 82 may be used to rotate crank shaft 68 which in turn rotates shaft 40. Shaft 40 then rotates forward pulleys 38 which cause cable 58 to extend or retract attached rear slat 60. Rear slat 60 extends or retracts the tarpaulin 28 to cover or uncover the truck bed 12. It should be noted that the upper sides of truck bed 12 are completely covered by the tarpaulin 28 extending over L-shaped lateral tarpaulin supports 32. Likewise the truck bed 12 is completely covered and sealed or shielded by tarpaulin 28 at the front portion of the truck by the attachment of the tarpaulin 28 to the cab shield 20. The rear of the truck is likewise sealed or shielded and covered by stationary tarpaulin 35 which seals or shields the truck bed 12 in the rear portion. The truck bed 12 is thus completely sealed or shielded from the outside when the tarpaulin 28 has been extended completely over the truck bed 12. No other known similar invention accomplishes this total sealing or shielding. Total covering and sealing or shielding is important in covering such truck loads as asphalt or other volatile mixtures as well as sand, gravel and the like. Some states (Pennsylvania ) require that the truck bed of asphalt containing trucks be completely covered and sealed or shielded from the outer atmosphere. Truck had sealing or shielding devices which do not create this total seal or shield may not legally operate in such states. Further, the present invention is contained solely within the lateral limits of the truck bed 12. No protruding devices extend laterally from the truck 10, hence the legal width of the truck is not compromised nor are extending parts damaged. In operation hollow tube 75 of removable hand crank 74 is placed over crank shaft 68 allowing notches 77 to engage shaft pin 76. Assuming that the truck cover is in the open position, removable hand crank 74 is turned, turning shaft 68 and attached chain sprocket 72, turning chain 78 which rotates short shaft 44, hollow shaft 40 and forward pulleys 38. Attached cable 58 than moves pulling rear slat 60 and attached tarpaulin 28 toward the rear of the truck bed 12. Rear slat 60 and attached tarpaulin 28 pass over stationary tarpaulin cover 35 and abut rear pulleys 50 thus sealing or shielding the rear of bed 12. L-shaped lateral tarpaulin supports 32 and attached tarpaulin 28 extend downwardly over the outer side walls 14 completely covering and sealing or shielding the interior of bed 12 from the outside. Reversing the direction of the removable hand crank 74 will cause cable 58 to pull rear slat 60 and attached tarpaulin 28 toward the front wall 18, thus exposing the interior of bed 12. Although the invention has been applied specifically to truck beds, it is contemplated that it may be used to cover other enclosures as well, such as bins, cans or containers, or used as roof covering for buildings, trailers or the like. Referring now to Figures 10 and 11, there is shown a tarpaulin support apparatus 101 for supporting tarpaulin 28 over truck bed 12. A plurality of tarpaulin support apparatuses 101 take the place of the slats 26 shown in Figure 1. Tarpaulin support apparatus 101 comprises a slat 103, slat support platforms 105 and 107 mounted on slat 103, and a lateral tarpaulin support 109 mounted on the end of each slat 103 over the tarpaulin 28 and extending downwardly over and adjacent to the side walls 14 of the truck 10 for holding the side portions 111 of the tarpaulin 28 close to the side walls 14 of the truck 10. Slat 103, which is preferably made of one-inch square hollow metal tubing, has a central portion 113 that extends between the side walls 14 of truck 10. A first end portion 115 of slat 103 extends from one end of the central portion 113 downwardly over and adjacent to one of the truck side walls 14, and a second end portion 117 of slat 103 extends from the other end of the central portion 113 downwardly over and adjacent to the other truck side wall 14. Slat support platforms 105 and 107 provide means for supporting slat 103 on the top of side walls 14 of the truck 10. Each of slat support platforms 105 and 107 comprises three six-inch long, one-inch square hollow metal tubings 119 welded together. Slat support 105 is welded to the slat first end portion 115 and slat support platform 107 is welded to the second slat end portion 117. Slat support platforms 105 and 107 have a bottom portion 121 that is adapted to rest on and to slide on the top of truck side walls 14. Each slat support platform 105 and 107 is provided with a pair of bores 123 that extend through slat support platforms 105, 107, and that are adapted to receive operating cables 125. Bores 123 are provided with a hollow sleeve insert or nipple 127 which receives the frictional forces provided from cables 125,126. Preferably, the sleeve inserts 127 are made from metal such is a copper and brass composite. The lateral tarpaulin supports 109 act as a means for holding the tarpaulin 28 on the slats 103. Tarpaulin 28 is held in place by being sandwiched between a lateral tarpaulin support 109 and a slat 103, the lateral tarpaulin support 109 and slat 103 being secured together by a plurality of self-drilling screws 129. Lateral tarpaulin supports 109 also act as side holding means for holding the tarpaulin side portions close to the side walls of the truck and for minimizing the space between the tarpaulin side portions and the side walls of the truck to limit the passage of air into and from the truck bed via the space between the tarpaulin side portions and the side walls of the truck while permitting the tarpaulin to be extended and retracted freely over the truck bed. As shown in Fig. 11, a bolt, with a corresponding nut and washer, is used to secure the lower side portion of tarpaulin 28 between lateral tarpaulin support 109 and slat 103. However, a self-drilling screw 129 may also be used in its place. Preferably, slat 103, slat support platforms 105 and 107, and lateral tarpaulin supports 109 are made of aluminum or steel. Preferably, slat first and slat second end portions 115 and 117, and the corresponding lateral tarpaulin supports 109, extend approximately six inches below slat support platforms 105, 107 and twelve inches above slat support platforms 105, 107. The slat central portion 113 is preferably bow-shaped. Accordingly, under this configuration, the truck bed is provided with approximately an additional foot in height of storage space above the side walls 14 of truck 10. The actual dimensions, however, may be varied to obtain the desired storage dimensions. In operation, the slats 103, together with tarpaulin 28 attached thereto, are extended and retracted over the truck bed 12 using substantially the same operating mechanisms previously described. However, under this embodiment, cable 125 extends twice through slat support platform 105, and operating cable 126 extends twice through slat support platform 107 and, except for the rear slat 103, in a sliding relationship. Rear slat 103, as shown in Fig. 11, has the end portions of cables 125, 126 secured to it with the use of a lock washer and nut 131 screwed onto the ends of the cables which are provided with threaded rods. Referring to Fig. 10, a one-inch wide, three-eighths-inch thick plastic strip 131, such as one made of polyethylene, is mounted on the top of each side wall 14 of the truck 10. A hole 133 is counterdrilled every seven inches in the top of the truck side walls 14, and the plastic strip 131 is secured to the top of the truck aids walls 14 by pan-head metal screws 135 screwed into the holes 133. This strip 131 reduces the frictional forces between the slats and the top of the truck side walls as the tarpaulin is extended and retracted over the truck bed.

Claims: A tarpaulin support apparatus (101) for supporting a tarpaulin (28) over a bed (12) of a truck (10) comprising a slat (103) having a central portion (113) that extends between a first side wall (14) of the truck (10) and a second side wall (14) of the truck (10), a first end portion (115) extending from the end of the central portion (113) downwardly over and adjacent to the first side wall (14) of the truck (10), and a second end portion (117) extending from the other end of the central portion (113) downwardly over and adjacent to the second side wall (14) of the truck (10), slat support means for supporting the slat (103) on the side walls (14) of the truck (10), and attachment means (109) for attaching the tarpaulin (28) to the slat (103), characterized in that the slat support means includes a first slat support platform (105) mounted on the first end portion (115) of the slat (103), the first slat support platform (105) having a bottom wall adapted to rest on and to slide on the top of the first side wall (14) of the truck (10), and a second slat support platform (107) mounted on the second end portion (117) of the slat (103), the second slat support platform (107) having a bottom wall adapted to rest on and to slide on the top of the second side wall (14) of the truck (10). A tarpaulin support apparatus (101) in accordance with claim 1, said attachment means (109) including a lateral tarpaulin support (109) mounted on the end of the slat (103) over the tarpaulin (28) and extending downwardly over and adjacent to the side walls (14) of the truck (10) for holding the tarpaulin (28) close to the side walls (14) of the truck (10). A tarpaulin support apparatus (101) in accordance with claims 1 or 2, the first and the second end slat support platforms (105,107) being provided with bores (123) adapted to handle operating cables (125). A tarpaulin support apparatus (101) in accordance with any preceding claim, the slat central portion (113) being bow-shaped. A tarpaulin support (101) in accordance with any preceding claim, the slat (103) being made of aluminum. A tarpaulin support apparatus (101) in accordance with any preceding claim, the slat (103) being made of steel. A tarpaulin support apparatus (101) in accordance with any preceding claim, the space between the tarpaulin (28) and the side walls (14) of the truck (10) being approximately three-quarters of an inch. Apparatus as claimed in any of the preceding claims, comprising front pulleys mounted to the front portion of the truck bed, an axle connecting the front pulleys, rear pulleys mounted to the rear portion of the truck bed, cables extending between the front pulleys and the rear pulleys in looping relationship, the slats extending between said cables and being attached thereto in a slipping relationship, cable connecting means for connecting the cables to a slat, and bi-directional rotating means for rotating the axle. Apparatus as claimed in claim 8, further including front enclosure means for enclosing the front of the truck bed. Apparatus as claimed in claim 9 the front enclosure means including a clamp member securing the front end portion of the tarpaulin to the front of the truck bed. Apparatus as claimed in any of claims 8 to 10, further including rear enclosure means for enclosing the rear of the truck bed. Apparatus as claimed in claim 11, the rear enclosure means including a rear retaining member attached to and extending between the side walls of the truck bed, and a stationary tarpaulin attached to the rear retaining member and to the rear wall of the truck bed. Apparatus as claimed in any of claims 8 to 12 in which the bi-directional rotating means includes a hand crank, a hand crank sprocket connected to said hand crank, an axle sprocket attached to said axle, and a chain connecting said hand crank sprocket to said axle sprocket. Apparatus as claimed in claim 13, in which the tarpaulin operating mechanism is substantially contained within the lateral width of said truck bed. Apparatus as claimed in claim 13, in which the rotating mechanism controlling the tarpaulin longitudinal movement is contained within the width of the truck bed.

Inventors: SEMION ROBERT, WEAVER ROBERT C, SEMION, ROBERT, WEAVER, ROBERT C.
Applicants: IMBT JOHN H, SEMION ROBERT, IMBT, JOHN H., SEMION, ROBERT
Application year: 1990
Main classification: B60P7
IPC codes: B60J7