Self-Storing Sliding Hydraulic Booster For Trailer

Abstract

A spread axle assembly for a trailer has the ability to pivot about itself to achieve a storage configuration that advantageously shortens the overall length of the trailer and reduces tire wear. It also has the ability to extend between a close position in which the rear axle of the trail is proximate to its axle and one or more spread or extended positions for better distribution of a load carried by the trailer.

Claims

1. A self-storing spread axle assembly for carrying part of a load carried by a trailer, the assembly comprising: a rear portion having an axle; a front portion for attachment to the trailer; a pivot; and a hydraulic cylinder attached to the front portion and the rear portion and arranged to pivot the rear portion around the pivot and above the front portion as the hydraulic cylinder goes from an extended state to a compact state.

2. The assembly of claim 1 further comprising a stand for holding the rear portion above the front portion.

3. The assembly of claim 1 wherein the pivot is a first pivot, and the assembly further comprises a second pivot around which the rear portion pivots relative to the front portion, the second pivot arranged to allow the rear portion to pivot up or down to compensate for unevenness of a surface supporting the assembly.

4. The assembly of claim 1 further comprising a pivot permitting the axle to turn right or left relative to the front portion.

5. The assembly of claim 5 further comprising a latch mechanism for locking the axle in a position substantially perpendicular to a longitudinal direction of the trailer.

6. The assembly of claim 1 wherein the front portion further comprises a plurality of beams extending longitudinally substantially parallel to a longitudinal direction of the trailer.

7. A trailer for transporting a load, the trailer comprising: a coupler for attachment to a tractor, the coupler located at a front end of the trailer; a rear axle for wheels, the rear axle for supporting the load; an axle assembly located behind the rear axle, the axle assembly comprising an axle for supporting the load; and a telescopic beam extending over the rear axle and attached to the axle assembly, the telescopic beam permitting the distance between the rear axle and the axle to be selectively adjusted.

8. The trailer of claim 7 wherein the telescopic beam has an aperture corresponding to a distance of 13′1″ or 14′1″ between the rear axle and the axle.

9. The trailer of claim 8 further comprising a latch mechanism for the aperture in the beam.

10. The trailer of claim 9 further comprising hose supports selectively insertable in the apertures.

11. The trailer of claim 7 wherein the telescopic beam comprises an external beam and an internal beam slidable within the external beam.

12. The trailer of claim 11 wherein the internal beam is attached to the axle assembly.

13. The trailer of claim 12 wherein the trailer comprises a first slide wheel for contacting a top surface of the internal beam proximal an outlet of the external beam where the internal beam enters the external beam, the first slide wheel facilitating the telescoping of the telescoping beam.

14. The trailer of claim 13 wherein the trailer comprises a second slide wheel for contacting a bottom internal surface of the external beam proximal an end of the internal beam and attached to the internal beam, the second slide wheel facilitating the telescoping of the telescoping beam.

15. The trailer of claim 7 wherein the telescopic beam is a first telescopic beam and the trailer further comprises a second telescopic beam extending over the rear axle and attached to the axle assembly.

16. The trailer of claim 15 wherein the trailer comprises a frame attached to the coupler and the rear axle, the frame comprising the first and second telescopic beams.

17. The trailer of claim 7 wherein the trailer has rear wheels attached to the rear axle and the axle assembly further comprises a rear portion having the axle; a front portion attached to the telescopic beam; a pivot; and a hydraulic cylinder attached to both the front portion and the rear portion and arranged to flip the rear portion around the pivot and above the front portion and above the rear wheels as the hydraulic cylinder goes from an extended state to a compact state.

18. A method of storing and transporting a spread axle assembly of a trailer on the trailer, the spread axle assembly comprising (1) a rear portion having an axle, (2) a front portion attached to the trailer, (3) a pivot, (4) a hydraulic cylinder attached to both the front portion and the rear portion, the method comprising: pulling the rear portion towards the front portion with the hydraulic cylinder causing the rear portion to pivot around the pivot and to be positioned over the front portion.

19. The method of claim 18 further comprising attaching a stand to hold the rear portion over the front portion.

20. The method of claim 19 further comprising transporting the trailer with the rear portion over the front portion.

21. A method of adjusting the distance between the rear axle of a trailer and an axle of a spread axle assembly, the trailer having (1) a coupler for attachment to a tractor, the coupler located at a front end of the trailer and (2) a telescopic beam extending over the rear axle and attached to the spread axle assembly; the method comprising: telescoping the telescopic beam in or out until a desired distance is achieved; and locking an inner beam of the telescopic beam relative to the outer beam of the telescopic beam.

22. The method of claim 21 wherein telescoping the telescopic beam comprises setting a brake on the spread axle assembly and towing the trailer towards or away from the spread axle assembly.

23. The method of claim 21 wherein the locking comprises inserting a deadbolt into the telescopic beam.

24. The method of claim 21 wherein the inner beam has a plurality of spaced apart apertures, wherein the locking comprises inserting a deadbolt into one of the apertures.

25. The method of claim 24 further comprising inserting a support into one of the apertures and supporting a hydraulic hose, an air hose or an electrical wire extending from the trailer to the spread axle assembly with the support.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is an elevation view of a tractor pulling a lowboy trailer with a booster in an extended position carrying a load.

[0024] FIG. 2 is an elevation view of the lowboy trailer shown in FIG. 1 (without wheels) with the booster in the extended position.

[0025] FIG. 3 is an elevation view of a rear portion of the trailer shown in FIG. 1 with the booster in a storage position.

[0026] FIG. 4 is an elevation view of the rear portion shown in FIG. 3 with the booster in the close coupled position.

[0027] FIG. 5 is an perspective view from above and from the left of the rear portion shown in FIG. 3 with the booster in the extended position. The wheels on the right side have been omitted for clarity.

[0028] FIG. 6 is an elevation view of the rear portion shown in FIG. 5 with the rear axle articulated downwards.

[0029] FIG. 7 is an elevation view of the rear portion shown in FIG. 5 with the rear axle articulated upwards.

[0030] FIG. 8 is a plan view from above of the booster shown in FIG. 1 without the rear axle and wheels.

[0031] FIG. 9 is a plan view from above of the booster shown in FIG. 1 without the rear axle and wheels.

[0032] FIG. 10 is a plan view from below of the booster shown in FIG. 1 without the rear axle and wheels.

[0033] FIG. 11 is a cross-sectional perspective view from the side along line 11-11 shown in FIG. 8.

[0034] FIG. 12 is a perspective view of a hose support shown in FIG. 5.

[0035] FIG. 13 is a perspective view of the front end of a beam shown in FIG. 5.

[0036] FIG. 14 is a cross-sectional perspective view from the side along line 14-14 shown in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

[0037] FIG. 1 illustrates the left side of a tractor 20 pulling a trailer 22 having a spread axle assembly 24 and carrying a load 26 (shown schematically as a box) on a surface 28 (such as a road or ground if off road). The right side is substantially similar to the left side. Tractor 20 may be any kind of tractor include ones suitable for on-road use and ones for off-road use (not including railroads). Typically, tractor 20 has a steering axle 30 attached to two steering wheels 32 including tires 33 and one or more drive axles 34, each attached to four drive wheels 36 including tires 37, and a suitable trailer hitch 38 for attaching tractor 20 and trailer 22 together.

[0038] With reference to FIGS. 1 and 2, trailer 22 may be any suitable trailer including a lowboy trailer or an open deck or platform trailer. As illustrated in the figures, trailer 22 is a lowboy trailer which is frequently used for hauling large and heavy equipment particularly construction and mining equipment. At its front end 39, trailer 22 has a gooseneck 40 having a hitch coupler such as a kingpin for coupling with trailer hitch 38. Gooseneck 40 may be removable allowing a load 26 to drive onto trailer 22 (and trailer deck 42). Typically, there can also be conventional electrical, air or hydraulic connections, wires or hoses (not shown) between the tractor 20 and trailer 22 for operating the brakes, brake lights, etc. and extending to spread axle assembly 24. Trailer 22 has a support surface or trailer deck 42 supporting load 26 and one or more trailer axles 44, typically two or three axles 44, attached to trailer wheels 46 including tires 47. The last of axles 44, or rear trailer axle, is denoted by reference numeral 44r.

[0039] With particular reference to FIGS. 1, 2, 5 and 8, trailer 22 has a trailer frame 48 extending over axles 44 and through gooseneck 40 and includes two or more parallel beams 50. The hitch coupler is attached, preferably mounted, to frame 48. Beams 50 are of the box type, preferably having 4 closed sides for most of their length. Inside each beam 50 is a beam 52, which can also be of the box type, which can be slid in and out of beam 50. The combination of one beam 50 and one beam 52 may be considered to constitute a single telescopic beam that can telescope in and out. Beams 52 are shown extended out in FIGS. 1, 2, and 5-8 and retracted in FIGS. 3 and 4. Beams 52 have spaced apertures 54 which in conjunction with a latch mechanism 56 locks the extension of beams 52 relative to beams 50. Latch mechanism 56 is attached to frame 48 and can be a conventional air-operated deadbolt latch having a bolt 56a that closely fits apertures 54 and can be withdrawn or inserted into an aperture 54. A switch 57 may be used to operate the bolt. Preferably, there are two latch mechanisms 56, one for each beam 52. The bolt can be secured in the locked position by a clevis pin. Preferably, the bolt extends through both beam 50 and beam 52. Latch mechanism 56 could also be a solenoid, a manually operated or hydraulically operated deadbolt latch.

[0040] As shown in FIGS. 5 and 8, there is a hose support 58 inserted into one of apertures 54. Additional hose supports 58 may be used as necessary. As shown in FIG. 12, hose support 58 has a loop 60 through which conventional air and hydraulic hoses and electrical wires (not shown) can be run so that such hoses and wires can extend from rear axle 44r to spread axle assembly 24. Hose support 58 is held in place in an aperture 54 by loop 60 on one side and by a pin 62 on the other side. Removal of pin 62 allows hose supports to be removed and placed in appropriate apertures 54 depending on the degree of extension or retraction of beams 52.

[0041] To facilitate the telescoping of beams 50 and 52, preferably two slide wheels are provided. As can be best seen in FIGS. 5 and 11, located close to each outlet 63 of beam 50, where beam 52 enters beam 50, is a slide wheel 64 which is in contact with a top surface 65 of beam 52. As can be best seen in FIG. 13, at the end 69 of beam 52 is a slide wheel 66. Slide wheel 66 is located inside beam 50. It contacts an inner bottom surface 67 of beam 50.

[0042] Behind rear axle 44r is a rear bumper 68 in case spread axle assembly 24 is disconnected from trailer 22.

[0043] Turning now to spread axle assembly 24, which is shown in greater detail in FIGS. 3-10, beams 52 are attached to a front portion 70 of spread axle assembly 24. Front portion 70 has a cross bar 72, which are attached to beams 52. Spread axle assembly 24 also has one or more upper hinges 74 and one more lower hinges 76, a rear portion 78, and a hydraulic cylinder 80. Hinges 74 and 76 connect front portion 70 and rear portion 78 together and permit rear portion 78 to pivot vertically relative to front portion 70. Hinges 74 and 76 have pivot axes 75 and 77, respectively, that are substantially perpendicular to a longitudinal direction 104 of trailer 22. Preferably there are two upper hinges 74, each having removable upper pivots or hinge pins 82, which are substantially horizontally aligned. Preferably there are two lower hinges 76, each having removable lower pivots or hinge pins 84, which are substantially horizontally aligned.

[0044] Hydraulic cylinder 80 is pivotally attached to cross bar 72 and pivotally attached to rear portion 78. Hydraulic cylinder 80 is of conventional construction and has conventional parts including a piston and a piston rod 85. Piston rod 85 is shown connected to rear portion 78, but the cylinder could be reversed such that piston rod 85 is attached to cross bar 72. Hydraulic cylinder 80 is in an extended state as shown in FIG. 4 and in a compact state in FIG. 3. Piston rod 85 is attached to rear portion 78 by a clevis 122 and a pin 124. Clevis 122 has two positions (a close position 126a and a distal position 126b) for pin 124. Each position 126 is formed by a pair of opposed apertures in clevis 122.

[0045] Rear portion 78 has a triangular frame 86, a rear frame 88, and one or more axles 90. Rear frame 88 is pivotally attached to triangular frame 86 by pivot 92, which is substantially vertically aligned when trailer 22 is on level ground, allowing axle 90 to turn left or right relative to triangular frame 86 and front portion 70. Rear frame 88 has a central triangular frame portion 93. Axle 90 is attached to rear frame 88 by a suspension 94. Suspension 94 may be a spring suspension, an air-ride suspension, a hydraulic suspension or a combination. As shown, suspension 94 is an air-ride suspension having air bags 95. The hydraulic system for spread axle assembly 24 (and suspension 94) includes hydraulic accumulator 96, hydraulic cylinder 80, and related conventional hydraulic hoses, tubing, etc. (not shown). In FIGS. 8-10, axle 90 has been omitted for clarity, but cradles 98, which are part of suspension 94, for axle 90 are shown. Conventionally, trailer 22 or tractor 20 has a hydraulic power pack (not shown) which can be used for operating hydraulic cylinder 80 and charging suspension 94. The hydraulic system of spread axle assembly 24 also has a hydraulic lock valve 99 (shown schematically) for isolating the hydraulic system of spread axle assembly 24 from the hydraulic system of the rest of trailer 22.

[0046] At the very back of spread axle assembly 24 is located a rear light bar 100.

[0047] Rear portion 78 has a latch mechanism 102 for locking axle 90 in a position substantially perpendicular to longitudinal direction 104 (substantially horizontal and in the plane of the paper in FIG. 1) of trailer 22. Latch mechanism 102 is located proximal to the tip of central triangular frame portion 93. Latch mechanism 102 includes a deadbolt 106 which can extend through and closely fits an aperture 108 in triangular frame 86 and an aperture 110 in rear frame 88. Deadbolt 106 may be air-operated using air switch 111 (shown schematically), hydraulically operated, manually operated or electrically-operated such as a solenoid.

[0048] Spread axle assembly 24 also has one or more stands 112 (two shown) which are pivotally attached to one of front portion 70 and rear portion 78 and removably attached to the other by a clevis pin 114 or similar. Axle (or axles 90) have wheels 116 (typically four per axle) having tires 118.

[0049] In operating trailer 22, the operator, without any assistance, will be able to easily change spread axle assembly 24 from a storage position shown in FIG. 3, to a close coupled position (see FIG. 4), to a spread or extended position (see FIG. 5), and to positions between the close coupled position and the spread or extended position. Additionally, after the appropriate non-storage position is selected the spread axle assembly may be operated in selected to a hydraulic booster configuration to carry a portion of load 26 and allowing pivoting up and down due to surface unevenness as shown in FIGS. 6 and 7.

[0050] When it is desired to move to booster from the stored position (see FIG. 1), a conventional hydraulic power pack (not shown) on trailer 22 or tractor 20 is started. Stands 112 are un-pinned, i.e., clevis pin 114 is removed from stands 112. The hydraulic controls of the power pack are used to extend out piston rod 85 causing rear portion 78 to pivot around upper pivots 82 and to lower to the ground. Once piston rod 85 is fully extended and tires 118 on surface 28, lower hinge pins 84 are installed in lower hinges 76. The trailer hydraulic power pack can then be shut off. Spread axle assembly 24 is in the close coupled position (see FIG. 4).

[0051] If it is desired to move spread axle assembly 24 to a spread or extended position, the brakes are set on axle 90/wheels 116. The bolts of latch mechanisms 56 are released from apertures 54 with switch 57 after removing the clevis pin. Tractor 20 is slowly moved forward towing trailer 22 forward and extending beams 52 (or telescoping the telescopic beams out) until they are close to the desired position. Switch 57 is activated. The tractor and trailer are slowly moved until the bolts of latch mechanisms 56 engage the appropriate apertures 54. Apertures 54 are located advantageously along beams 52 to achieve, for example, a distance 120 of 13.1 and 14.1 feet between rear axle 44r and axle 90. Shorter distances are also advantageous for reducing the overall length of trailer 22 such as 12′1″, 11′1″, 10′1″, 9′2″ and a close position. Optionally, hose supports 58 can be inserted into apertures 54 and hoses and wires supported by hose supports 58.

[0052] Before spread axle assembly 24 is used, it is preferable to allow pivoting around pivot 92 to eliminate or reduce skidding of tires 118 around corners. To do so, deadbolt 106 is disengaged from at least one of aperture 108 and aperture 110 using air switch 111. The trailer can now be operated with spread axle assembly 24 as a fixed booster.

[0053] If it is desired to operate the spread axle assembly 24 as a hydraulic booster, the hydraulic power pack is started and pin 124 is removed from distal position 126b. Using the hydraulic controls of the hydraulic power pack, piston rod 85 is moved inwardly and pin 124 is inserted into close position 126a thereby reattaching piston rod 85 to rear portion 78. Next, upper pivots or hinge pins 82 are removed. Using the hydraulic controls, hydraulic accumulator 96 is charged pushing axle 90 downwardly relative to rear frame 88 thereby shifting an increasing amount of the weight of load 26 to axle 90 until the desired loading on axle 90 is achieved. Once the desired loading has been reached, hydraulic lock valve 99 is closed to prevent pressure loss. Spread axle assembly 24 can now be operated as a hydraulic booster. Hydraulic cylinder 80, which remains in hydraulic communication with hydraulic accumulator 96, gives axle 90 increased travel to keep axle loadings consistent over uneven roads (see FIGS. 6 and 7). It is possible to achieve an additional 18″ of total travel up and down in the booster configuration.

[0054] If it is desired to return spread axle assembly 24 from its hydraulic booster configuration to the stored position (see FIG. 1), hydraulic lock valve 99 is opened. The hydraulic pressure in hydraulic accumulator 96 is relieved using the hydraulic controls. The hydraulic power pack is started and upper hinge pins 82 are installed in upper hinges 74. Deadbolt 106 is engaged with both aperture 108 and aperture 110 using air switch 111 to prevent pivoting around pivot 92, which could be dangerous during transport.

[0055] The connection of piston rod 85 to clevis 122 is adjusted. First, pin 124 is removed. Next, using the hydraulic controls, piston rod 85 is moved outwardly and piston rod is reattached to clevis 122 by inserting pin 124 into distal position 126b. The brakes are set on spread axle assembly 24. The bolts of latch mechanisms 56 are released from apertures 54 with switch 57. Trailer 22 is towed by tractor 20 backwards, telescoping the telescopic beams in until the spread axle assembly gently hits the rear of trailer stops. Switch 57 is activated, engaging latch mechanisms 56 thereby locking beams 52 in the closed position. Next lower hinge pins 84 are removed. Using the hydraulic controls, piston rod 85 is retracted pulling rear portion 78 toward front portion 70 causing rear portion 78 to rise. Stands 112 are pinned to using clevis pins 114. The hydraulic power pack is shut off. The trailer can now be operated with the booster in the stored position (see FIG. 3).

[0056] As can be seen, the invention overcomes deficiencies discussed in the background. Additionally, hydraulic cylinder 80 is advantageously used to improve the suspension of the spread axle assembly.

[0057] Definitions: As used in this application, substantially vertical and substantially horizontal directions mean that when trailer 22 is on horizontal and level surface 28, e.g., the ground, that the directions are vertical and horizontal, respectively, subject to manufacturing tolerances and normal wear and tear including uneven tire wear. In any case, substantially vertical and substantially horizontal should not deviate more than 5 degrees from vertical or horizontal, respectively. Similarly, substantially perpendicular or substantially parallel reflect manufacturing tolerances and normal wear and tear, but should not deviate more than 5 degrees from perpendicular or parallel, respectively.

[0058] While the invention has been described with respect to certain embodiments, as will be appreciated by those skilled in the art, it is to be understood that the invention is capable of numerous changes, modifications and rearrangements, and such changes, modifications and rearrangements are intended to be covered by the following claims.