AU712454B2 - Improved folding log trailer - Google Patents

Description

-1- P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventor: Address for service BLACKWOOD ENGINEERING PTY LTD Christopher Woodbridge in Australia: CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia Invention Title: IMPROVED FOLDING LOG TRAILER Details of Associated Provisional Application: PN9914 filed 17 May 1996 The following statement is a full description of this invention, including the best method of performing it known to us -2- IMPROVED FOLDING LOG TRAILER INTRODUCTION TO INVENTION This invention relates to flatbed and logging trailers and in particular to such trailers capable of being folded back onto the prime mover when empty for ease of transport.

BACKGROUND TO INVENTION Flatbed and logging trailers are open trailer units designed to carry heavy and bulky loads without necessarily relying on protective cover for said loads. Such trailers have a distinct advantage over covered trailers in providing ease of loading and unloading in addition to weight reductions.

A further advantage of such trailer types is the ability to incorporate a folding mechanism to allow the empty trailers to be collapsed upon themselves and folded up for compact transport of the empty trailer unit.

Such folding trailers are known; however, the existing folding trailers have certain disadvantages.

In particular, existing folding trailers comprise a two part body hinged at or about midway along their length with two hydraulic rams or other activating devices also positioned midway so as to traverse the hinge mechanism and adapted to fold by causing the two parts of said trailer to fold about the mid hinge thereby lifting the middle hinged section of the trailer above the ground. As the folding of such trailers progresses that part attached to the turntable of the prime mover passively pivots causing the trailer to lift up until the wheels of the trailer are drawn up to the rear of the prime mover. However, at this point, such trailers cannot proceed further to draw the folded trailer off the ground and up onto the prime mover. The prime mover must be reversed to cause the folded trailer to mount the prime mover.

Accordingly, the current mechanisms suffer from an inability to complete the folding operations over center and therefore, it is necessary for current folding trailers to be fully folded by the assistance of the attached primer mover reversing to complete the fold and mount the trailer. Such manipulations are time consuming, awkward and dangerous. Furthermore, the mid hinge positioning of the hydraulic rams forces the 12 May 1997 MAW:PP:#20696.CAP -3rams to lift both halves of the folding trailer thereby placing unnecessary strain on the rams.

OBJECT AND STATEMENT OF INVENTION One object of this invention is to provide an improved folding trailer.

Accordingly, in one aspect, the invention provides a folding trailer comprising a foldable trailer body having a first body part and a second body part wherein said first body part incorporates an axle assembly at a first end thereof and said second body part is adapted for articulated and hinged fitting to a prime mover, or the link trailer of a double B, at a first end thereof and the second ends of both body parts are hinged together for pivotal movement between an unfolded position with said first and second body parts forming a substantially unitary trailer body and a primary o• folded position with said first and second body parts folded onto each other and a So" secondary folding position with the combined first and second body parts inturn folded back onto said prime mover or link trailer wherein said folding movements are effected by the single active pivoting of said second body part about said first i" •"end at the hinged fitting at the turntable of said prime mover or link trailer and the passive movement of said first body part following the second body part so as to cause said first body part and said second body part to be folded onto each other and further causing the combined first and second folding body parts to be folded back onto said prime mover or link trailer thereby mounting the entire trailer assembly onto the prime mover or link trailer.

The hinged fitting preferably includes an intermediate nutation bracket fitted between the second body part and the turntable with the nutation bracket being passively pivoted to the turntable and adapted for movement over a limited arc relative to said turntable and the first end of the second body part is actively pivoted to the nutation bracket at a position removed from the passive pivot.

The active pivoting is preferably effected by a hydraulic ram connected to the nutation bracket and the second body part.

12 May 1997 MAW:PP:#20696.CAP -4- The juxtapositioning of the active pivot, passive pivot and connection of the hydraulic ram is preferably chosen to allow the full primary folding of the trailer to be effected without any substantial movement of the passive pivot. Such a juxtaposition could have the active pivot positioned forward of the passive pivot which, in turn, is positioned forward of the point of fitting of the hydraulic ram to the nutation bracket.

The invention will now be described in detail with reference to a particularly preferred embodiment as shown in the accompanying Figures 1 to 6 and the prior art shown in Figure 7.

Figure 1 shows the extended bi-folding trailer fitted to a prime mover.

Figure 2 shows the trailer initiating the folding action.

go o Figure 3 shows the trailer in a semi-folded state.

Figure 4 shows the trailer fully folded and retracted or mounted on a prime mover.

*.i Figures 5 to 7 show working detail of the folding mechanism and turntable.

Figure 8 shows plan detail of the folding mechanism and turntable.

Figures 9 and 10 show the fully folded and mounted trailer fitted to a Bdouble.

Figure 11 shows a schematic representation of prior art bi-folding trailers.

Referring briefly to the prior art, Figure 11 shows the current system used to S.I activate bi-folding trailers by way of centrally located dual hydraulic rams. The prior art bi-folding trailers share many features with the trailer of the invention including two body parts; a first body part 1 having an axle assembly and provision for wheels 2 at a first end 3 and a second body part 4 which is adapted for articulated attachment at a first end 3 via the turntable 5 to a prime mover or other driving means. Both the first and second body parts are hinged together at their respective second ends 6 by way of a hinge means 7 so as to allow the first and second body parts of the trailer to fold up. The turntable 5 also incorporates a hinge or pivot 8 to allow the two body parts of the folding trailer to freely hinge up about the turntable. The current method used to activate such folding trailers incorporates MAW:PP:#20696.CAP 12 May 1997 dual hydraulic rams 9 which attach to the respective second ends of both halves of the trailer and bridge the hinge 7 such that activation of the rams causes the two body parts to lift or fold up about the hinge connection 7 and thereby to fold up so far as the full extension of the hydraulic rams shown in Figure 11 will allow.

However, at the point shown in Figure 1IB, the hydraulic rams have reached full extension and are unable to fold the two body parts further and particularly are not able to cause the folded trailer to "mount" the prime mover. At this stage, it is necessary for the prime mover to reverse up to fully fold the two halves of the trailer together and cause the fully folded assembly to ride up on to the prime mover as shown in Figure 1 IC. The need to rely on the prime mover to fully load such current folding trailers presents a limitation to such prior art devices.

DETAILED DESCRIPTION OF THE INVENTION In the description of the invention, the term "active pivot" means a pivot about which a force is exerted to cause the pivoted means to move. The term "passive pivot" means a pivot about which a force is not required to directly cause the pivoted means to move but where the pivoting action is caused by shift in weight or pressure about the pivot point.

The invention has relocated a single hydraulic ram 9 as shown in Figure I to the second body part 4 so as to actively pivot the second body part about the hinge or active pivot 11 which connects the first end 3 of the second body part 4 to the turntable 5. The relocation of the hydraulic ram completely alters the mechanics of =oo I the folding action and allows the consecutive primary folding action and secondary folding or mounting action to be accomplished by the action of one ram without the need for the prime mover to reverse.

Figure 1 shows the fully extended trailer comprising a foldable trailer body made up of two halves being a first body part 1 and a second body part 4. The first body part has an axle and wheel assembly 2 positioned at a first end 3 with a hinge 7 provided at a second end 6 for hinged fitting thereof to a second body part 4 at a second end 6 thereof. The first end 3 of the second body part is provided with a hinged engagement to the turntable 5 fitted to the chassis of the prime mover. The MAW:PP:#20696CAP 12 May 1997 -6second body part is activated by an hydraulic ram 9 for pivoting about the active pivot 11.

Referring to Figure 2, from the position of being extended, the folding of the trailer is affected by activating the hydraulic ram 9 to extend which causes the lifting or elevation of the second body part of the trailer 4 relative to the prime mover 13.

The connection of the first and second body parts at hinge 7, causes the first body part to passively follow the active elevation of the second body part 1 with the wheels 2 remaining in contact with the ground and allowing the two parts of the trailer configuration to fold up and move toward the prime mover 13 as shown in Figure 3. The continued extension of the hydraulic ram 9 is shown in Figure 4 with the resultant folding of the second body part 4 and first body part 1 onto each other :as a primary fold and additionally, both first and second folded body parts are *--secondarily folded, as a unit, so as to mount the prime mover 13 with the wheels of the first body part 2 removed from the ground such that the whole trailer is now S" 15 fully supported on the prime mover and not in contact with the ground thereby allowing the prime mover to proceed without being in any way encumbered by the folded trailer. The particular details of the complete folding action are shown with reference to Figures 5 to 7 where the details of the connection of the second body o..

***part to the turntable of the prime mover are shown.

Referring firstly to Figure 5, the turntable 5 is fitted to the chassis of the prime mover 13 in the usual manner. However, the turntable incorporates an intermediate nutation bracket 10 between the articulation plate of the turntable which is connected to the prime mover 13, and the active pivot point 11 where the folding trailer is hinged to the turntable. The nutation bracket is passively pivoted to the articulation plate of the turntable 5 at 12 such that the nutation bracket is capable of passively moving through a small arc relative to the chassis of the prime mover 13.

At full extension, during normal operation of the trailer and during the majority of the process of folding the fully extended trailer, the nutation bracket assumes a neutral pivoting position and function as shown in Figures 1 to 3, 5 and 12 May 1997 MAW:PP:#20696.CAP -7- 6; and only at the secondary folding action shown in Figures 4 and 7, where the first body part and second body part are, in fact, folded as far as possible and the wheels 2 of the first body part have lifted off the ground that the nutation bracket is passively activated by the movement of the combined folded trailer over the center of the pivot 12 allowing the folded trailer to rock forward under its own weight so as to fully and securely mount the prime mover. The passive rocking of the folded trailer, using the flexibility of the nutation bracket, allows the folded trailer to securely mount the prime mover without requiring the hydraulic ram to extend over center of the active pivot.

The unfolding or extending of the trailer involves essentially the reversal of the actions effected in the previously discussed folding action. From the fully folded o• and mounted position, the hydraulic ram 9 is activated and begins to retract, pulling >-"with it the folded first and second body parts and causing, as a first action, the returning of the nutation bracket to the neutral pivot position as the center of gravity of the folded trailer shifts about the passive pivot 12; from there, the hydraulic ram continues to retract causing the second body part to pivot away from the prime mover until the wheels of the first body part 2 contact the ground when the continued retraction of the ram causes the second body part and first body part to straighten by the passive movement of the first body part away from the prime mover following the action of the hydraulic ram and the unfolding of the hinge 7.

The extension action is finished when the hydraulic ram 9 is fully contracted and the S"first and second body parts adopt a linear and extended configuration.

Referring now to Figure 8, a plan view is provided of the prime mover/turntable mechanism. The relative positions of the hydraulic ram 9, its location 17 on the articulation plate of the turntable 5, the position of the passive pivot 12 of the nutation bracket 10 and the position of the active pivot 11 of the second body part 4 are shown juxtaposed sequentially in order to provide maximum mechanical advantage for the hydraulic ram 9.

MAW:PP:#20696.CAP 12 May 1997 -8- Figures 9 and 10 show the folding trailer of the invention applied to a double B type system. The folding trailer is attached to the rear trailer 15 of the double B in a similar manner to the attachment to a prime mover. The folding trailer can be made to mount the rear trailer as shown in Figure 10 to allow the double B to operate as a single articulated trailer.

The invention provides a unique, compact, reliable and safe mechanism for use in bi-folding trailers which provides many advantages over the known prior art.

In particular, the ability of the trailer to be fuilly folded and activated without the particular interaction of the prime mover provides a far more efficient and reliable operation of the trailer requiring less particular or peculiar skills of the driver of the prime mover which in turn provides a much safer unit. In addition, the positioning S: of the hydraulic ram at the environment of the prime mover and the positioning of the ram within the mechanisms of the turntable, provide physical protection and minimise the exposure of this important part of the mechanism in clear contrast to the prior art where the hydraulic rams are located in the middle of the trailer and .exposed to physical and environmental abuse. Furthermore, the unique mechanism of the invention, particularly incorporating the preferred embodiment of the nutation bracket provides particular mechanical advantage to the action of the trailer and maximises the efficiency of the hydraulics of the mechanism and thereby improve the life of the whole mechanism.

0 MAW:PP:#20696.CAP 12 May 1997

Claims (4)

1. A folding trailer comprising a foldable trailer body having a first body part and a second body part wherein said first body part incorporates an axle assembly at a first end thereof and said second body part is adapted for articulated and hinged fitting to a prime mover at a first end thereof and the second ends of both body parts are hinged together for pivotal movement between an unfolded position with said first and second body parts forming a substantially unitary trailer body and a primary folded position with said first and second body parts folded onto each other and a secondary folding position with the combined first and second body parts are inturn folded back onto said prime mover wherein said folding movements are effected by the single active pivoting of said second body part about said first end at the hinged i fitting at the turntable of said prime mover and the passive movement of said first body part following the second body part so as to cause said first body part and said second body part to be folded onto each other and further causing the combined first and second folding body parts to be folded back onto said prime mover thereby mounting the entire trailer assembly onto the prime mover wherein said hinged fitting :includes a nutation bracket intermediate of said second body part and said tumrntable such that the nutation bracket is passively pivoted to said turntable and adapted for movement over a limited arc relative to said turntable and the first end of said second 20 body part is actively pivoted to said nutation bracket at a position removed from said •passive pivot.

2. A folding trailer according to claim 1, wherein said second body part is activated by a hydraulic ram fitted to said second body part and said nutation bracket so as to cause the second body part to pivot relative to said nutation bracket and said turntable.

3. A folding trailer according to claim 2 wherein said active pivot is positioned forward of said passive pivot and said hydraulic ram is fitted to said second body part at one end and to said nutation bracket at a position aft of said passive pivot at the other end.

4. A folding trailer according to claim 3 wherein the juxtaposition of said MAW:NP:#20696.RS 1 15 September 1999 active pivot, said passive pivot and the fitting of the hydraulic ram to the nutation bracket allows the hydraulic ram to effect said primary folding of the trailer without activating the passive pivot of the nutation bracket. A folding trailer according to any one of claims 1 to 4 substantially as hereinbefore described with particular reference to the accompanying drawings. DATED: 15 September 1999 CARTER SMITH BEADLE Patent Attorneys for the Applicant: BLACKWOOD ENGINEERING PTY LTD o MAW:NP:#20696.RS1 15 September 1999