CA1202651A - Tandem trailer system - Google Patents
Tandem trailer systemInfo
- Publication number
- CA1202651A CA1202651A CA000420019A CA420019A CA1202651A CA 1202651 A CA1202651 A CA 1202651A CA 000420019 A CA000420019 A CA 000420019A CA 420019 A CA420019 A CA 420019A CA 1202651 A CA1202651 A CA 1202651A
- Authority
- CA
- Canada
- Prior art keywords
- trailer
- chassis
- wheels
- beams
- pair
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Body Structure For Vehicles (AREA)
- Regulating Braking Force (AREA)
Abstract
TANDEM TRAILER SYSTEM
ABSTRACT OF THE DISCLOSURE
An intermediate trailer for use between a standard tractor and a standard trailer, the intermediate trailer having a chassis mounted at its rear end, consisting of a first portion which is fixed to the trailer and a second portion which is slidable relative to the first portion from a first position under the trailer to a second position extending rearwardly of the trailer, the second portion having wheels mounted thereon.
ABSTRACT OF THE DISCLOSURE
An intermediate trailer for use between a standard tractor and a standard trailer, the intermediate trailer having a chassis mounted at its rear end, consisting of a first portion which is fixed to the trailer and a second portion which is slidable relative to the first portion from a first position under the trailer to a second position extending rearwardly of the trailer, the second portion having wheels mounted thereon.
Description
~Z~3t~>~
In the transportation industry, the use of tandem trailer rigs has become very important, mainly because of its cos-t~effectiveness. This is because such an arrangement uses only one driver and one tractor at a time, while the load carrying capacity is twice as great. The main difficulty experienced in the past with the using two trailers in tandem is the method by which they are joined together. If, for instance, one uses a standard bogie, there are two arti:cul.ations, one of which is under the rear end of the front trailer and one of which is under the front end of the rear trailer. S:uch a double articulation is dangerous, because it permits:several kinds of buckling and similar motions between the two. tr.ai.lers, thus leading to accidents. In my patents 3,933,374 and 4:,030,171, I suggested that a solution to this dangerous problem could be brought about by use of an extension protruding beyond the rear of the front trailer. While this arrangement is generally satisfactory, it has the drawb.ack that.the intermediate trailer is almost entirely committed to use in tandem rigs and has very little use for running single. Further-20 more, it is difficult to back. up to a loading dock even whenit is provided with the hinged platform shown in the patent..
These and other difficulties e~perienced wlth.the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding obj:ect of:the invention to provide a tandem trailer system in which .the connection between the trailers provides a single point of pivot or articulation.
~2t~Z~i53L
Another object of this invention is the provision of a tandem trailer system in which the connection between the trailers remains permanently with one of the trailers and, therefore, is not subject to pilferage or vandalism, as is true when a bogie is left by itself~
It is another object of the instant invention to provide a tandem trailer system in a special forward trailer, which special trailer can be used by itself.
It is another object of the instant invention to provide a tandem trailer system in a special forward trailer, which special trailer can be used by itself.
A still further object of the invention is the provision of a tandem trailer system in which the connection between the trailers remains permanently with the front trailer, which front trailer, nevertheless, can be moved close to a loading dock~
It is a further object of the invention to provide a tandem trailer system which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
With these and other obj.ects in view, as will be apparent to..those skilled in the art, the invention resides in the combination of parts set forth in the speci~ication and covered by claims appended hereto.
In general, the invention consists of a trailer unit adapted to be drawn behind a highway tractor and behind which unit:can be drawn a second standard trailer. The unit consists of a cargo. container and a chassis on which the container is mounted. The.chassis has a first upper portion and a second lower portion, the second portion being ~Z(~i51 longitudinally slidable relative to the first portion from a first position generally co-extensive with the firs-t portion to a second position where it extends beyond the end of the cargo container. A first attaching means is associated with the front end of the container for connection to the highway tractor and a second attaching means is associa-ted with -the second portion of the chassis, so that, when the second portion is in second position, another trailer can be attached to it.
Wheels are mounted on the said second portion of the chassis.
More specifically, a pair of locking pins are mounted on the second portion for transverse movement to engage apertures in the first portion when the second portion is in the first or second position; the pins, thereforet serve -to hold the first and second portions against relative sliding movement in the first and second position. The wheels are provided with pneumatic brakes and the locking pins are provided with a pneumatic actuator cylinder. A selector valve is provided to connect a source of pressure air selectively to the brakes or the cylinder, so that the locking pins are released when the brakes are locked and the pins are engaged when the brakes are free. The lower portion is provided with three pairs of wheels, the wheels being mounted so that one pair is at the front end of the lower portion, one pair is at the rear end, and one pair is in the middle; the second attaching means is a fifth wheel located between the middle and rear pair of wheels.
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings r in which:
FIG. 1 is a side elevational view of a trailer unit embodying the principles of the present invention showing two trailers operating in tandem, FIG. 2 is side elevational view of a front trailer at a loading dock, FIG. 3 is a side evelational view of the trailer unit using only one trailer, FIG. 4 is a rear elevational view of the trailer unit taken on the line IV IV of FIG. 3, FIG~ 5 is a transverse vertical sectional view of the trailer unit taken on the line V-V of FIG. 3, FIG. 6 is an enlarged sectional view of a portion of the apparatus, FIG. 7 is a horizontal sectional view of the apparatus, FIGS. 8 and 9 are schematic cross-sectional views of.the invention, showing locking means in two different conditions, FIG. lO is an enlarg.ed transverse sectional view of a portion of the apparatus showing a locking pin in use, FIG. 11 is a schematic circuit view of pneumatic apparatus: used in the trailer unit.
FIG. 12 is a side elevational view of a portion of the trailer unit, FIG. 13 is a transverse vertical sectional view of a portion of the trailer unit, ~a, _ ~z~
FIG~ 14 is a side elevational view of a portion of the trailer unit, FIGa 15 is a plan view of the trailer unit during turning, and FIG~ 16 is a side elevational view of the trailer unit.
Referring first to FIG~ 1~ which best.shows the general features of the invention, the trailer unit, indicated generally by the reEerence numeral 10, is shown as being drawn behind a highway tractor 11. The trailer unit in turn, is drawing a second trailer unit 12 behind ltself. The trailer unit 10 consists of a cargo container 13, at the rear end of which is.carried a chassis 14~ The chassis has a first upper portion 15 and a second lower portion 16. The second portion 16 is longitudinally slidable relative to the first portion 15 from a first position in which it is generally co-extensive with the first portion to a second portion in which it extends beyond the end of the.cargo container 13, as shown in FIG~ 1~
A first at-taching means 17 extends downwardly from the forward portion of the container 13 for connection to the fifth wheel .20 of the tractor 11. A second attaching means 18 in the form of a fifth wheel is associated with the second portion 16 of the chassis, so that, when the second portion is in the second position, another trai.ler 12 can be attached to it. A set 19 of whe~els is mounted on the said second portion of the: chassis.
FIG~ 2 shows the manner in which the container 13 can be unloaded. The second portion 16 remains in the .second position, but a platform is provided to allow a l.ift truck or similar unloading apparatus to be carried into the container.
FIG~ 3.shows the manner in which the container 13 can be moved over the road by its:elf behind the tractor 11.
5:~L
The second portion 16 is in the first position, that is to say, is co-extensive with the first portion of the. chassis. At that time the attaching means 18 lies under the container and the wheels 19 are entirely beneath the container.
Referring next to FIGS. 4, 5, and 6, which shows the details of the fi.rst portion 15 and the second porti~on 16, it:can be seen that the first portion 15 is provided with two spaced, parallel I-beams 21 and 22. The second portion 16 consists of two similar I-beams 23 and 24 held in spaced, parallel relationship. As shown in FIG. 6, the undersurface 25~of:the I-beam 21 rests on the~ upper surface 26 of the I-beam 16, while a similar relationship takes place between the I-beams 22 and 24. Guides 27 are attached to the I-beams 23 and 24 and form part of the second portion 16; these guides . envelope the bottom inner flanges of the upper I-beams.21 and.22.
.As shown in FIGS. 7, 8, and 9, a pair of lock.ing pins.28 and.29 are mounted on the second portion 16 for . transverse movement to engage apertures 31 of the first portion 15 when the .second portion 16 is in the first or s~econd position.
. These pin~ serve to hold the first and second portions against relati.ve:sliding movement when in the said first or second positions.
FIG. 10 shows the details of the locking pin:28 and.the manner in which.it engages an aperture 31.
Referring to FIG. 11, it can be seen that the wheels 19 are provided with pneumatic brakes 32, while the locking pins:28 and:29 are provided with a pneumatic actuator cylinder 33. . A se:lector valve 34 is provided to conn~ect a source of pressure air selectively to the brakes 32 or the cylinder 33 ~L~ 65:~L
so that the locking pins are released when the brakes are locked and the pins are engaged when the brakes are free. The brakes are provided with the conventional system, including a valve 46, for use when running over the road.
FIG~ 6 shows the provision of slide pads, formed preferably of Teflon, attached to the upper surface 26 of the I-beams 23 and 24 to facilitate sliding motion between the first and second portions. The ~uides:27 are also provided with side pads 36 to facilitate relative sliding of the I-beams 26 and 22.
As is par-ticularly evident in FIG o 1~ the lower portion 16 is provided with three pairs of wheels 37, 38 and 39, these making up the set 19 of wheels. The wheels are mounted so that.the one pair 37 is located at the ront of the lower portion 16, one pair 39 is at the rear end, and one pair 38 lies between them substantially closer to the set 37.
A second attaching means 18 in the form of a fifth wheel is located between the middle and rear pair of wheels 3g and 39, repectively.
As is particularly evident in FIG. 2, a platform 41 is provided between the. cargo container 13 and the rear end of the chassis 14. The platform can be moved so that it extends only a short distance beyond the rear end of the container.
The platform is hingedly. connected to the.chassis near the rear end of the cargo container and normally lies against the container door 42. A cable 43 is. connected to the platform to.control its movement. Legs are provided to support the platform against movement even if considerable weight is placed on it.
FIG. 12 shows the manner in which a leaf spring 47 is mounted on the second portion 16 of the chassis. It overlies and supports the axle 48 of the wheel set 39 in such a way that
In the transportation industry, the use of tandem trailer rigs has become very important, mainly because of its cos-t~effectiveness. This is because such an arrangement uses only one driver and one tractor at a time, while the load carrying capacity is twice as great. The main difficulty experienced in the past with the using two trailers in tandem is the method by which they are joined together. If, for instance, one uses a standard bogie, there are two arti:cul.ations, one of which is under the rear end of the front trailer and one of which is under the front end of the rear trailer. S:uch a double articulation is dangerous, because it permits:several kinds of buckling and similar motions between the two. tr.ai.lers, thus leading to accidents. In my patents 3,933,374 and 4:,030,171, I suggested that a solution to this dangerous problem could be brought about by use of an extension protruding beyond the rear of the front trailer. While this arrangement is generally satisfactory, it has the drawb.ack that.the intermediate trailer is almost entirely committed to use in tandem rigs and has very little use for running single. Further-20 more, it is difficult to back. up to a loading dock even whenit is provided with the hinged platform shown in the patent..
These and other difficulties e~perienced wlth.the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding obj:ect of:the invention to provide a tandem trailer system in which .the connection between the trailers provides a single point of pivot or articulation.
~2t~Z~i53L
Another object of this invention is the provision of a tandem trailer system in which the connection between the trailers remains permanently with one of the trailers and, therefore, is not subject to pilferage or vandalism, as is true when a bogie is left by itself~
It is another object of the instant invention to provide a tandem trailer system in a special forward trailer, which special trailer can be used by itself.
It is another object of the instant invention to provide a tandem trailer system in a special forward trailer, which special trailer can be used by itself.
A still further object of the invention is the provision of a tandem trailer system in which the connection between the trailers remains permanently with the front trailer, which front trailer, nevertheless, can be moved close to a loading dock~
It is a further object of the invention to provide a tandem trailer system which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
With these and other obj.ects in view, as will be apparent to..those skilled in the art, the invention resides in the combination of parts set forth in the speci~ication and covered by claims appended hereto.
In general, the invention consists of a trailer unit adapted to be drawn behind a highway tractor and behind which unit:can be drawn a second standard trailer. The unit consists of a cargo. container and a chassis on which the container is mounted. The.chassis has a first upper portion and a second lower portion, the second portion being ~Z(~i51 longitudinally slidable relative to the first portion from a first position generally co-extensive with the firs-t portion to a second position where it extends beyond the end of the cargo container. A first attaching means is associated with the front end of the container for connection to the highway tractor and a second attaching means is associa-ted with -the second portion of the chassis, so that, when the second portion is in second position, another trailer can be attached to it.
Wheels are mounted on the said second portion of the chassis.
More specifically, a pair of locking pins are mounted on the second portion for transverse movement to engage apertures in the first portion when the second portion is in the first or second position; the pins, thereforet serve -to hold the first and second portions against relative sliding movement in the first and second position. The wheels are provided with pneumatic brakes and the locking pins are provided with a pneumatic actuator cylinder. A selector valve is provided to connect a source of pressure air selectively to the brakes or the cylinder, so that the locking pins are released when the brakes are locked and the pins are engaged when the brakes are free. The lower portion is provided with three pairs of wheels, the wheels being mounted so that one pair is at the front end of the lower portion, one pair is at the rear end, and one pair is in the middle; the second attaching means is a fifth wheel located between the middle and rear pair of wheels.
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings r in which:
FIG. 1 is a side elevational view of a trailer unit embodying the principles of the present invention showing two trailers operating in tandem, FIG. 2 is side elevational view of a front trailer at a loading dock, FIG. 3 is a side evelational view of the trailer unit using only one trailer, FIG. 4 is a rear elevational view of the trailer unit taken on the line IV IV of FIG. 3, FIG~ 5 is a transverse vertical sectional view of the trailer unit taken on the line V-V of FIG. 3, FIG. 6 is an enlarged sectional view of a portion of the apparatus, FIG. 7 is a horizontal sectional view of the apparatus, FIGS. 8 and 9 are schematic cross-sectional views of.the invention, showing locking means in two different conditions, FIG. lO is an enlarg.ed transverse sectional view of a portion of the apparatus showing a locking pin in use, FIG. 11 is a schematic circuit view of pneumatic apparatus: used in the trailer unit.
FIG. 12 is a side elevational view of a portion of the trailer unit, FIG. 13 is a transverse vertical sectional view of a portion of the trailer unit, ~a, _ ~z~
FIG~ 14 is a side elevational view of a portion of the trailer unit, FIGa 15 is a plan view of the trailer unit during turning, and FIG~ 16 is a side elevational view of the trailer unit.
Referring first to FIG~ 1~ which best.shows the general features of the invention, the trailer unit, indicated generally by the reEerence numeral 10, is shown as being drawn behind a highway tractor 11. The trailer unit in turn, is drawing a second trailer unit 12 behind ltself. The trailer unit 10 consists of a cargo container 13, at the rear end of which is.carried a chassis 14~ The chassis has a first upper portion 15 and a second lower portion 16. The second portion 16 is longitudinally slidable relative to the first portion 15 from a first position in which it is generally co-extensive with the first portion to a second portion in which it extends beyond the end of the.cargo container 13, as shown in FIG~ 1~
A first at-taching means 17 extends downwardly from the forward portion of the container 13 for connection to the fifth wheel .20 of the tractor 11. A second attaching means 18 in the form of a fifth wheel is associated with the second portion 16 of the chassis, so that, when the second portion is in the second position, another trai.ler 12 can be attached to it. A set 19 of whe~els is mounted on the said second portion of the: chassis.
FIG~ 2 shows the manner in which the container 13 can be unloaded. The second portion 16 remains in the .second position, but a platform is provided to allow a l.ift truck or similar unloading apparatus to be carried into the container.
FIG~ 3.shows the manner in which the container 13 can be moved over the road by its:elf behind the tractor 11.
5:~L
The second portion 16 is in the first position, that is to say, is co-extensive with the first portion of the. chassis. At that time the attaching means 18 lies under the container and the wheels 19 are entirely beneath the container.
Referring next to FIGS. 4, 5, and 6, which shows the details of the fi.rst portion 15 and the second porti~on 16, it:can be seen that the first portion 15 is provided with two spaced, parallel I-beams 21 and 22. The second portion 16 consists of two similar I-beams 23 and 24 held in spaced, parallel relationship. As shown in FIG. 6, the undersurface 25~of:the I-beam 21 rests on the~ upper surface 26 of the I-beam 16, while a similar relationship takes place between the I-beams 22 and 24. Guides 27 are attached to the I-beams 23 and 24 and form part of the second portion 16; these guides . envelope the bottom inner flanges of the upper I-beams.21 and.22.
.As shown in FIGS. 7, 8, and 9, a pair of lock.ing pins.28 and.29 are mounted on the second portion 16 for . transverse movement to engage apertures 31 of the first portion 15 when the .second portion 16 is in the first or s~econd position.
. These pin~ serve to hold the first and second portions against relati.ve:sliding movement when in the said first or second positions.
FIG. 10 shows the details of the locking pin:28 and.the manner in which.it engages an aperture 31.
Referring to FIG. 11, it can be seen that the wheels 19 are provided with pneumatic brakes 32, while the locking pins:28 and:29 are provided with a pneumatic actuator cylinder 33. . A se:lector valve 34 is provided to conn~ect a source of pressure air selectively to the brakes 32 or the cylinder 33 ~L~ 65:~L
so that the locking pins are released when the brakes are locked and the pins are engaged when the brakes are free. The brakes are provided with the conventional system, including a valve 46, for use when running over the road.
FIG~ 6 shows the provision of slide pads, formed preferably of Teflon, attached to the upper surface 26 of the I-beams 23 and 24 to facilitate sliding motion between the first and second portions. The ~uides:27 are also provided with side pads 36 to facilitate relative sliding of the I-beams 26 and 22.
As is par-ticularly evident in FIG o 1~ the lower portion 16 is provided with three pairs of wheels 37, 38 and 39, these making up the set 19 of wheels. The wheels are mounted so that.the one pair 37 is located at the ront of the lower portion 16, one pair 39 is at the rear end, and one pair 38 lies between them substantially closer to the set 37.
A second attaching means 18 in the form of a fifth wheel is located between the middle and rear pair of wheels 3g and 39, repectively.
As is particularly evident in FIG. 2, a platform 41 is provided between the. cargo container 13 and the rear end of the chassis 14. The platform can be moved so that it extends only a short distance beyond the rear end of the container.
The platform is hingedly. connected to the.chassis near the rear end of the cargo container and normally lies against the container door 42. A cable 43 is. connected to the platform to.control its movement. Legs are provided to support the platform against movement even if considerable weight is placed on it.
FIG. 12 shows the manner in which a leaf spring 47 is mounted on the second portion 16 of the chassis. It overlies and supports the axle 48 of the wheel set 39 in such a way that
2~
the axle underlies the pivotal axis of the second attaching means 18.
FIG, 13 shows the manner in which the second attaching means 18 is located within the space defined by the first portion 15 of the chassis. This feature permits it to reside under.the container 13 when the second portion i5 nested under the container, as shown in FIG. 3.
FIG. 14 shows the manner in which the second portion 16 o~ the chassis is provided with a leaf spring 49 to support the axle 51 of the front wheels 37. A leaf spring 52 with a stabilizer.53 is used to support the axle 54 associa-ted with the intermediate wheels 38.
In FIGS. 15 and 16 are shown the cables 55 carried by the second portion 16 to supply electrical current and pressure air to the rear trailer 12. These cables are carried on a rod 56 which is connected to the second portion 16 through a flexible spring 57. The dimensions of the cables 55, rod 56, and spring 57 are selected to permit them to lie between the I-beams.23 and 24 of the second portion 16 when it is in the first position under the first portion 15, as indicated in broken lines. FIG. 15 shows the manner in which the location of the s.econd attaching means 18 is selected to allow the forward corners o.f the rear trailer 12 to avoid contact during turning with the rear o~ the front railer 13.
.The operation and advantages of the present invention will now be readily understood in view of the above description.
In FIG. 1, which shows two trailers 12 and 13 in tandem, it can be seen that the only connection between them is at the at-taching means 18, which means that a single pivot joins the trailers and the dangers of articulation about two pivots is ~2~5`~
not present, There is no bogie that would be left behind when the rear trailer is dropped off at its destination or when a portion of the highway is reached in which tandem operation is forbidden. Normally~ the unloading of the container 13 wouId take place in the manner shown in FIG. 2 with the platform 41 in horizontal position, having been lowered to that position by means of a cable 43. A plate 44 rests on the fifth wheel 18 and legs 45 are provided to give additional support for the platform. This allows a forklift truck to enter the. container from -the dock.
At the time when the rear trailer has been dropped off it is possible to use the trailer 13 and the tractor 11 by themselves. At that time, the apparatus takes the condition shown in FIG. 3.
In order to move.the lower portion 16 from one position to another, it is possible to use the braking system shown in FIG. 11. If the valve 34 is operated to move the actuating cylinder 33, the locking pins 28 and.29 are in l:ocked position and the brakes 32 are free, so that the apparatus 20 can roll on the wheels 37, 38 and 39 without difficulty. When it is necessary to move the lower portion 16 from one position to the other, this is done also by means of the valve 34.
If, for instance, the portion 16 is shown in the condition shown in FIG. 1 and it is desired to move it to the first position shown in FIG. 3, i-t is only necessary to move the valve 34 to a second position in which the brakes 32.receive pressure air, thus locking them against rolling. At .that time the cylinder 33 is released, thus allowing the springs in the system to pull the locking pins.28 and 29 out of their position 31. .When this is done, the tractor and the container 13 are _g_ ~Z~5~
moved backwardly. Since the wheels brakes 32 in the wheels 19 are locked in place this causes the firs-t portion 15 of the chassis 14 to slide rearwardly over the second portion 16.
~ventually, a limiting position is reached, as shown in FIG. 3, and the valve 34 is changed back to the position shown in FIG. 11 where the actuating cylinder 33 causes the locking pin to move into place and lock them in the first or front condition, the wheels are, therefore, free. Tractor ll and the container 13 are then free to move over the road as a single unit. The normal brake system is operative on the brakes 32 at that time.
As shown in FIGS. 12 and 14, the axles 48,.51 and.54 are mounted above their respective springs by use of shackles.
This allows the use of standard size wheels, even though the second attaching means 18 is located at a low enough level to permit the rear trailer 12 to be a standard trailer unit.
FIG. 15 indicates the manner in which the entire unit, incl~l~;ng the tractor 11, the front trailer 13, and the rear trailer 12,. can turn on a very small radius. More specif.ically, the front corners of the rear trailer 12 clear the rear end of the front trailer 13 by substantial amounts during turning.
FIG. 16 shows clearly the way in which the cables 55 on their support rod.56 and spring.57 are pressed downwardly into a storage position when the second portion 16 slides from its rear, s.econd position to. its front, first position. When.the rever:se movement ta]~es place, the cables spring upwardly into the.functional position for: connection to the.coupling element on.the front end of the:rear trailer 12. An alarm is provided that .is. energized when .the pins are released and r~m~'n~
6~
operative when moving the sliding elements from one posi-tion to the other.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. I-t is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly . come within the scope: claimed~
. The invention having been thus de.scribed, what is claimed as new and desired to s.ecure by Letters Patent is:
the axle underlies the pivotal axis of the second attaching means 18.
FIG, 13 shows the manner in which the second attaching means 18 is located within the space defined by the first portion 15 of the chassis. This feature permits it to reside under.the container 13 when the second portion i5 nested under the container, as shown in FIG. 3.
FIG. 14 shows the manner in which the second portion 16 o~ the chassis is provided with a leaf spring 49 to support the axle 51 of the front wheels 37. A leaf spring 52 with a stabilizer.53 is used to support the axle 54 associa-ted with the intermediate wheels 38.
In FIGS. 15 and 16 are shown the cables 55 carried by the second portion 16 to supply electrical current and pressure air to the rear trailer 12. These cables are carried on a rod 56 which is connected to the second portion 16 through a flexible spring 57. The dimensions of the cables 55, rod 56, and spring 57 are selected to permit them to lie between the I-beams.23 and 24 of the second portion 16 when it is in the first position under the first portion 15, as indicated in broken lines. FIG. 15 shows the manner in which the location of the s.econd attaching means 18 is selected to allow the forward corners o.f the rear trailer 12 to avoid contact during turning with the rear o~ the front railer 13.
.The operation and advantages of the present invention will now be readily understood in view of the above description.
In FIG. 1, which shows two trailers 12 and 13 in tandem, it can be seen that the only connection between them is at the at-taching means 18, which means that a single pivot joins the trailers and the dangers of articulation about two pivots is ~2~5`~
not present, There is no bogie that would be left behind when the rear trailer is dropped off at its destination or when a portion of the highway is reached in which tandem operation is forbidden. Normally~ the unloading of the container 13 wouId take place in the manner shown in FIG. 2 with the platform 41 in horizontal position, having been lowered to that position by means of a cable 43. A plate 44 rests on the fifth wheel 18 and legs 45 are provided to give additional support for the platform. This allows a forklift truck to enter the. container from -the dock.
At the time when the rear trailer has been dropped off it is possible to use the trailer 13 and the tractor 11 by themselves. At that time, the apparatus takes the condition shown in FIG. 3.
In order to move.the lower portion 16 from one position to another, it is possible to use the braking system shown in FIG. 11. If the valve 34 is operated to move the actuating cylinder 33, the locking pins 28 and.29 are in l:ocked position and the brakes 32 are free, so that the apparatus 20 can roll on the wheels 37, 38 and 39 without difficulty. When it is necessary to move the lower portion 16 from one position to the other, this is done also by means of the valve 34.
If, for instance, the portion 16 is shown in the condition shown in FIG. 1 and it is desired to move it to the first position shown in FIG. 3, i-t is only necessary to move the valve 34 to a second position in which the brakes 32.receive pressure air, thus locking them against rolling. At .that time the cylinder 33 is released, thus allowing the springs in the system to pull the locking pins.28 and 29 out of their position 31. .When this is done, the tractor and the container 13 are _g_ ~Z~5~
moved backwardly. Since the wheels brakes 32 in the wheels 19 are locked in place this causes the firs-t portion 15 of the chassis 14 to slide rearwardly over the second portion 16.
~ventually, a limiting position is reached, as shown in FIG. 3, and the valve 34 is changed back to the position shown in FIG. 11 where the actuating cylinder 33 causes the locking pin to move into place and lock them in the first or front condition, the wheels are, therefore, free. Tractor ll and the container 13 are then free to move over the road as a single unit. The normal brake system is operative on the brakes 32 at that time.
As shown in FIGS. 12 and 14, the axles 48,.51 and.54 are mounted above their respective springs by use of shackles.
This allows the use of standard size wheels, even though the second attaching means 18 is located at a low enough level to permit the rear trailer 12 to be a standard trailer unit.
FIG. 15 indicates the manner in which the entire unit, incl~l~;ng the tractor 11, the front trailer 13, and the rear trailer 12,. can turn on a very small radius. More specif.ically, the front corners of the rear trailer 12 clear the rear end of the front trailer 13 by substantial amounts during turning.
FIG. 16 shows clearly the way in which the cables 55 on their support rod.56 and spring.57 are pressed downwardly into a storage position when the second portion 16 slides from its rear, s.econd position to. its front, first position. When.the rever:se movement ta]~es place, the cables spring upwardly into the.functional position for: connection to the.coupling element on.the front end of the:rear trailer 12. An alarm is provided that .is. energized when .the pins are released and r~m~'n~
6~
operative when moving the sliding elements from one posi-tion to the other.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. I-t is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly . come within the scope: claimed~
. The invention having been thus de.scribed, what is claimed as new and desired to s.ecure by Letters Patent is:
Claims (6)
- Claim 1 continued...
(f) a pair of locking pins mounted on the second portion for transverse movement to engage apertures in the first portion when the second portion is in the first or the second position and to hold the first and second portions against relative sliding movement when in the first or second position, the wheels being provided with pneumatic brakes, the locking pins being provided with a pneumatic actuator cylinder, and (g) a selector valve provided to connect a source of pressure air selectively to the brakes or the cylinder, so that the locking pins are released when the brakes are locked and the pins are engaged when the brakes are free. - 2. Trailer system as recited in claim 1, wherein slide pads are provided between the facing surfaces of the flanges of the I-beams, and wherein the guides are provided with slide pads on their surfaces that engage the flanges of the I-beams of the upper portion of the chassis.
- 3. Trailer system as recited in claim 1, wherein the lower portion is provided with three sets of wheels, the wheels being mounted so that one pair is at the front end of the lower portion, one pair is at the rear end, and one pair is located between the other two sets of wheels, and wherein the second attaching means is a fifth wheel located above the set of wheels located at the rear end of the lower portion.
- 4. Trailer system as recited in claim 1, wherein the first attaching means is a king pin suitable for connection to a fifth wheel and the second attaching means is a fifth wheel.
- 5. Trailer system as recited in claim 1, wherein electrical and pneumatic cables extend through the upper portion and are attached to a wand extending upwardly from the lower portion, the lower end of the wand being attached to the lower portion through a spring, so that the cables and wand can be bent downwardly when the lower portion is moved from the second position to the first position.
- 6. Trailer system as recited in claim 1, wherein the second attaching means is located on the lower portion far enough rearwardly that the front end of the second trailer unit can swing relative to the cargo container during turning without striking the rear end of the cargo container.
1. Trailer system to be drawn behind a highway tractor and behind which can be drawn a second trailer unit, comprising:
(a) a cargo container, (b) a chassis on which the container is mounted, the chassis having a first upper portion and a second lower portion, the second portion being longitudinally slidable relative to the first portion from a first position generally co-extensive with the first portion to a second position where it extends beyond the end of the cargo container, the first upper portion of the chassis consisting of a pair of I-beams held in spaced, parallel relationship for attachment to the container, the second lower portion of the chassis consisting of a similar pair of I-beams connected together in spaced, parallel relation-ship and underlying the first portion, so that the undersurface of the lower flange of each I-beam of the first portion is supported on the upper surface of the upper flange of the corresponding I-beam of the second portion, a plurality of guides being fixed to the I-beams of the second portion and embracing the lower flanges of the I-beams of the first portion, (c) a first attaching means associated with the front end of the container for connection to the highway tractor, (d) a second attaching means associated with the second portion of the chassis, so that, when the second portion is in the second position, another trailer can be attached to it, (e) wheels mounted on the said second portion of the chassis,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000420019A CA1202651A (en) | 1983-01-21 | 1983-01-21 | Tandem trailer system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000420019A CA1202651A (en) | 1983-01-21 | 1983-01-21 | Tandem trailer system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1202651A true CA1202651A (en) | 1986-04-01 |
Family
ID=4124412
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000420019A Expired CA1202651A (en) | 1983-01-21 | 1983-01-21 | Tandem trailer system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1202651A (en) |
-
1983
- 1983-01-21 CA CA000420019A patent/CA1202651A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6394734B1 (en) | Trailer having actuatable tail ramp | |
| CA2099290C (en) | Dockable container chassis | |
| CA1288113C (en) | Load positioning container chassis | |
| US4993737A (en) | Load-bearing multi-position drawbar arrangement and suspension system | |
| CA1316185C (en) | Trailer suspension system | |
| US7503742B2 (en) | Vehicle and equipment transport vehicle | |
| CA1088123A (en) | Multiple hook-up, movable axle, container cargo trailer | |
| US5860668A (en) | Semitrailer having an extendible dolly | |
| US4526395A (en) | Tandem trailer system | |
| US20090123260A1 (en) | Tilting bed trailer | |
| US6135700A (en) | Transport vehicle deck lowering mechanism | |
| EP1557345A2 (en) | Trailers for carrying containerised loads | |
| US2933053A (en) | Railway car for transporting trailer bodies | |
| US5018593A (en) | High lift tag axle for trucks | |
| US8262118B2 (en) | Vehicle power unit and body unit system | |
| US4400004A (en) | Tandem trailer system | |
| US6050578A (en) | Log trailer load booster | |
| US4111450A (en) | Multiple hook-up, movable axle trailer with removable track extensions, slidable kingpin, and pivotal axle assemblies | |
| US4153169A (en) | Loading-unloading capability for cargo box transport vehicle | |
| US4117906A (en) | Linear travel device for self-propelled articulated vehicle | |
| US4673191A (en) | Tandem trailer system | |
| CA1202651A (en) | Tandem trailer system | |
| US5988664A (en) | Apparatus for towing a disabled truck tractor | |
| US6505891B1 (en) | End dump fifth wheel trailer | |
| US6231064B1 (en) | Automotive transport tractors, semi-trailers, trailers and combinations thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |