Portable ramp assembly

[0001] The invention relates to ramps, especially to lightweight portable ramps that can be used in pick-up type trucks, as disclosed in U.S. Pat. No. 6,042,923. This patent describes a pair of ramps which are movable into and out of an opening in an, otherwise, enclosed envelope that is secured to the bed of a pick-up truck. It can be appreciated that dust and dirt can collect in such an envelope to hinder and obstruct movement of the ramps.

[0002] The invention relates to improvements in such portable ramps to overcome such problems and others which will become apparent to those skilled in the art.

[0008] With general reference to the drawing for like parts, and particular reference to FIG. 1, there is shown a pick-up truck 5 which has a flat bed 6 that is defined by three upstanding sides 7-9 and a tailgate 10 of the truck 5. There are a pair of similar, rear wheel fenders 11 which extend from the opposing side walls 7 and 9 towards each other to reduce the flat bed 6 from a rectangular shape to a dumbbell-like configuration.

[0009] A portable ramp assembly 15 is designed to be positioned on the flat bed 6, and is laterally sized to fit between the opposing wheel fenders 11, and is longitudinally sized to fit between the cab wall 8 and the opposing tailgate 10, when the tailgate 10 is closed in an upright position.

[0010] With particular reference to FIG. 2, the portable ramp assembly 15 comprises a housing 16 which has a rectangular, solid flat top plate 17 which is secured to, and supported in parallel relation with, the flat bed 6 by a pair of similarly sized, outer, solid flat side walls 18 and 19 and a similarly sized, solid flat inner wall 20 that is equally spaced between the outer side walls 18 and 19. The walls 18-20 are substantially coextensive with the length of the top plate 17. The outer side walls 18 and 19 have similarly sized, short flat flanges 21 and 22 which extend towards each other in parallel relation with the top plate 17 from adjacent opposing free marginal edges 23 and 24 of the outer side walls 18 and 19. The inner wall 20 has similarly sized, short flat flanges 25 and 26 which extend from the free marginal edge 27 of the inner wall 20 in opposing directions towards the opposing flanges 21 and 22 of the outer side walls 18 and 19. The short flanges 21,22,25 and 26 are coextensive with the length of the walls 18-20, and are in the same plane which is parallel to the plane of the top plate 17. The inner wall 20 divides the housing 16 laterally into two side-by-side, longitudinally extending and partially enclosed twin compartments 28 which have open ends 29, adjacent the tailgate 10, and opposing closed ends 30 adjacent the cab wall 8, when the housing 15 is properly positioned on the flat bed 6. The twin compartments 28 also have open bottoms 31, except for the short flanges 21,22,25 and 26. A plurality of similarly sized thin, but sufficiently rigid straps or cross ties 32 may be, optionally, secured to the short flanges 21,22,25 and 26 transversely of the housing 16 and longitudinally spaced thereon to make the housing 16 even more rigid, if desired.

[0011] The twin compartments 28 are designed to slidably receive a pair of similar ramps 35, each of which comprises a rectangular cover plate 36 which is randomly perforated with holes 37 to preferably provide a non-skid outer surface 38 which is less susceptible to the accumulation of dust and dirt. In some instances, the outer surface 38 of the ramps 35 can be smooth, or provided with a non-skid painted material. The perforated cover plates 36 are each secured at right angles to a pair of similarly sized, parallel side walls 41 and 42 which are coextensive with the length of the cover plates 36. The side walls 41 and 42 of each of the ramps 35 have a pair of opposing marginal edges 43 and 44 at which are disposed a pair of short flanges 45 and 46 which are in the same plane which is parallel to the plane of the cover plate 36. The short flanges 45 and 46 of the ramps 35 are supported on, and movable along, the adjacent short flanges 21,22,25 and 26 of the housing 16 in which the ramps 35 are stored.

[0012] A pair of hard and durable, similarly sized plastic guides 47 are disposed between the short flanges 45 and 46 of each of the ramps 35 and the supporting short flanges 21,22,25 and 26 of the housing 16. The plastic guides 47, as seen in FIG. 2, have rectangular cross sections, and are preferably secured to the short flanges 45 and 46 of the ramps 35 by any suitable means, e.g. screws or nuts and bolts. The plastic guides 47 terminate in closely spaced relation to the adjacent walls 18-20 of the housing 16 to help laterally guide the ramps 35 as they move along the short flanges of the housing 16. Further, the plastic guides 47 are at least partially longitudinally coextensive with the short flanges 45 and 46 of the ramps 35 to facilitate smooth movement of the ramps 35, rather than provide short plastic guides 47 to the short flanges 45 and 46 of the ramps 35 adjacent the leading and trailing ends 48 and 49 of the ramps 35.

[0013] The housing 16 is detachably secured to the truck bed 6 by any suitable means, e.g. similar L-shaped brackets 50 located at the four outside corners of the housing 16.

[0014] It should be apparent to one skilled in the art, that the portable ramp assembly 15 can be more easily, and less costly, fabricated from conventional components, as follows. The housing 16 is made of an aluminum top plate 17 which is from one quarter inches to one half inches thick and has a maximum width W of about forty-eight inches and a maximum length of about six or eight feet, depending on the length of the flat bed 6 which is about eight feet for a big pick-up truck 5, and about six feet for a small pick-up truck 5. The top plate 17 is welded to two outer side walls 18 and 19 which are standard four inch aluminum channel sections which have one-half inch thick webs and one-quarter inch thick short flanges. Further, the inner wall 20 can be two, four inch channel sections bolted or welded together in back-to-back relation, or it can be a single, conventional four inch I-beam which also has a one-half inch web and four outstanding short flanges which are one-quarter inches thick. The housing 16 and any cross-ties 31, if used, are preferably made of aluminum to make the housing 16 as light as possible, so that it can be easily lifted into and out of the flat bed 6 of a pick-up truck 5. It should also be appreciated that the housing 16 can be designed to hold a single ramp 35, a pair of twin ramps 35 as described herein, and even three separate ramps 35 in a forty-eight wide housing 16, if desired.

[0015] The ramps 35 can also be made of aluminum and customized to precisely fit within the side-by-side twin compartments 30 of the above-described forty-eight inch wide aluminum housing 16. However, stock lengths of prefabricated, perforated, two inch thick steel ramps 35 can be purchased in standard widths. For example, a stock ten inch wide prefabricated, steel ramp and a stock twelve inch wide prefabricated, steel ramp can be bolted or welded together in side-by-side relation to form a single ramp 35 which can be slidably mounted in each of the twin compartments 30 of the forty-eight inch wide housing 16. Such stock ramps 35 come with two differently sized perforations or holes 37 in the outer ramp surfaces 38 which can be smooth or non-skid which can be achieved by special paints or the perforations or holes 37. For example, the larger perforations or holes 37 are about one and one-quarter inch, in diameter, and the smaller holes are about one-quarter inch in diameter. The larger holes 37 are preferred, because dust, dirt and other debris are less likely to accumulated in them. The ramps 35 can each be made of one single section, or two dissimilar length sections which are hinged together, as seen in FIG. 3. For example, one piece ramps 35 can be used in applications where there is no tailgate, or when the tailgate 10 is removed or unhitched and moved out of interfering relation with the positioning of the ramps 35. Rather than unduly burden the user with such details, the portable ramp assemblies 15 are made with hinged ramps 35, so that the tailgate 10 can be generally aligned with the truck bed 6 to help support the ramps 35. In such cases, each ramp 35 is comprised of a short section 51 which is substantially as long as the tailgate 10 is wide, and a longer section 52 which [s rotatably mounted on the outer exposed end of the short section 51 by any suitable hinge 53, e.g. a piano-type hinge where the intermeshed knuckles 54 of the hinge 53 have a common pivot pin 55 and act as a relatively smooth transitional surface between the adjacent outer exposed surfaces 38 of the short and long sections 51 and 52 of each ramp 35. The outermost free or leading ends 56 of the long ramp sections 52 are at angles to provide better contact and smoother transition with a flat surface, and are provided with handholds 57, whereby the ramps 35 can be grabbed and pulled from the housing 16. The plastic guides 47, secured to the undersides of the short flanges 45 and 46 of each stock steel ramp 35, act to prevent corrosion from developing between the dissimilar metals of the aluminum of the housing 16 and the steel of the ramps 35.

[0016] It should be apparent from the above description that there is an abrupt offset or difference of about one to two inches between the outer exposed surface 17 of the housing 16 and the adjacent outer exposed surfaces 38 of the ramps 35, when the ramps 37 are fully extended from the housing 16. This situation is alleviated or highly improved when the ramps 35 are pulled from the housing, by the provision of four identical, unique lifting and stop (L&S) blocks 60, as best seen in FIGS. 3 and 4, in combination with certain adaptations made to the housing 16 and short ramp sections 51 of the ramps 35. Each one of the L&S blocks 60, when properly positioned in a level housing 16, has a ramp 61 which is inclined upwardly from the horizontal at an angle A of about fifteen degrees, and leads upwardly to a level platform 62 which is about one inch long and terminates at a one-half inch vertically offset stop 63 which is about one-half inches long. The L&S blocks 60 are made of any suitable tough wearing material such as steel or an aluminum alloy, and are about one-half inches thick, and are secured to the walls 18-20 of the housing 16 adjacent the outermost front end 64 of the housing 16, closest the tailgate 10, by any suitable means, e.g. screws or bolts. Each L&S block 60 has a bottom level surface 65 which is about six and three-eights inches long and is spaced about one and one-eighth inches from, and in parallel relation with, the short flanges 21, 22, 25 and 26 of the housing 16. The L&S blocks 60 each have a vertical flat back 66 which is about one and three-quarters inches long, and which is flush with the adjacent housing front end 64, when the L&S blocks 60 are secured to the housing 16.

[0017] The adaptations referred to in the previous paragraph include the provision of a forty-five degree chamfer 67 along the front top edge 68 of the top plate 16, and a solid, one-half inch diameter cylindrical steel bar or rod 69 which is welded in transverse relation across the innermost trailing or tail end 70 of each one of the short ramp sections 51. The rods 69 each have a pair of similar opposing ends 71 which extend or project beyond the adjacent opposing sides 41 and 42 of each ramp 35 for engaging the adjacent pair of L&S blocks 69 to slide upwardly along the block ramps 61 onto the platforms 62 where they come to rest after engaging the stops 63. The tops of the rods 69 are in general alignment with the outer, exposed perforated surface 38 of each of the short ramp sections 51. When the short ramp sections 51 are in such positions, the outer exposed surfaces 36 of the short ramp sections 51 are in close alignment with the underside of the top plate 17 of the housing 16. Thus, the reason for the chamfer 67 on the front edge 68 of the housing 16, i.e. to ramp the small offset between the adjacent outer exposed surfaces 16 and 51 of the housing 16 and ramps 35. The trailing end 70 of each of the short ramp sections 51 is cut away at a forty-five degree angle just below the steel rod 69 to remove a special ramp portion 72 which allows the leading end 56 of each ramp 35 to be tilted upwardly to allow the rod 69 to pass under and bypass the L&S blocks 60, whereby the ramps 35 can be removed from the housing 15, if desired. A dotted rod 69 is shown in FIG. 3 in a first position for initial engagement with the block ramp 61, and a second position where the rod 69 is escaping from the housing 16 between the bottom surface 65 of the L&S block 60 and the adjacent short flanges of the housing 16.

[0018] When short and long ramp sections 51 and 52 are used, it has been found advantageous to provide plastic guides 47 on the short flanges 45 and 46 of the short ramp sections 51 in combination with short plastic guides 47, shown in dotted line in FIG. 3, which are secured on the short flanges 21,22,25 and 26 of the housing 16 adjacent the open front end thereof. The normal size of the plastic guides 47 is such that they will not interfere with the escape of the short ramp sections 51 from the housing 16.

[0019] A number of similar hooks or eyes 73 can be strategically mounted on the housing 16 for receiving ropes or elastic tie downs with hooks for firmly holding down to the housing 16, such things as furniture. It can be appreciated that two relatively deep pockets are formed fore and aft of the rear tire fenders 11, when the housing 16 is, in position, on the truck bed 6. Such pockets are undesirable, because they are places where dirt and debris can accumulate This problem can be eliminated by securing atop the flat top plate 17, a second metal plate or piece of painted or waterproof plywood 74 which is shaped to completely cover the truck bed 6. A bead of calking can be used to seal the joints between the plywood 73 and adjacent sides of the truck bed 6 and the rear tire fenders 11, if desired.

[0020] The invention has been described in relation to a portable ramp assembly 15 which utilizes a housing 16 which is designed to accommodate two separate ramps 35. The invention can be used in housings 16 that are designed to hold one or more ramps 35, depending on the width of the housing 16. It should be mentioned that large pick-up trucks have an eight foot long flat bed which can accommodate an eight foot long housing 16 having one or more eight foot long ramps 35 which have been found to be ideally suited in the practice of this invention, as described. A problem arises when the invention is utilized in small pick-up trucks which have a flat bed which is only about six feet long. In such case, the length of the housing 15 and ramps 35 are not ideally sized, unless the six foot long ramps can be used with the tailgate 10 removed or in an unobstructing position. If not, the short six foot long ramps 35 must be lengthened by two feet to meet the ideal length of eight feet. This can best be done, for example, by mounting another short ramp section in telescoping relation within an open leading end of the longer ramp section of the six foot long ramp. In cases where the truck bed is higher, it will be necessary to provide even the eight foot long ramps 35 with telescoping ramp extensions so that the ramps 35 are at a desirable grade and not too steeply inclined.

[0021] Thus, there has been described a unique, lightweight, portable ramp assembly which is comprised of a housing and pair of ramps, and which can be attached to the flat bed of a pick-up truck, when such ramps are needed for loading such things as furniture or lightweight off the road vehicles onto the truck. The ramp assembly can be made of aluminum, steel, or plastic. However, for ease and simplicity of construction, the housing is built from conventional plate, channels and I-beams, and the ramps are preconstructed steel rams of standard lengths and widths and thickness. Special plastic guides are used to facilitate movement of the ramps within the housing. Also, unique blocks are used in the leading or front end of the housing to lift a specially adapted trailing end of each ramp to reduce any vertical offset which may occur between the outer exposed top surfaces of the housing and ramps.