CA1244852A - Weight transfer device for tractor trailer - Google Patents
Weight transfer device for tractor trailerInfo
- Publication number
- CA1244852A CA1244852A CA000530783A CA530783A CA1244852A CA 1244852 A CA1244852 A CA 1244852A CA 000530783 A CA000530783 A CA 000530783A CA 530783 A CA530783 A CA 530783A CA 1244852 A CA1244852 A CA 1244852A
- Authority
- CA
- Canada
- Prior art keywords
- air bag
- tractor
- weight transfer
- transfer device
- wheel
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D53/00—Tractor-trailer combinations; Road trains
- B62D53/04—Tractor-trailer combinations; Road trains comprising a vehicle carrying an essential part of the other vehicle's load by having supporting means for the front or rear part of the other vehicle
- B62D53/06—Semi-trailers
- B62D53/068—Semi-trailers having devices to equalise or modify the load between the fifth wheel and the rear wheels
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A weight transfer device for tractor trailer units includes an upward force-producing device mounted on a frame between the rear frame members of the tractor and behind the fifth wheel. The device is intended to transfer weight over the rear tractor drive wheels to increase their traction.
A weight transfer device for tractor trailer units includes an upward force-producing device mounted on a frame between the rear frame members of the tractor and behind the fifth wheel. The device is intended to transfer weight over the rear tractor drive wheels to increase their traction.
Description
:~2'~ 2 FIELD OF THE INVENTION
The present invention relates generally to devices adapted to distribute the weight of a tractor trailer more efficaciously.
BACKGROUND OF THE INVENTION
It is very well known in the art to provide devices of the above type. The desired effect o such devices is to shift weight to the front axle of the tractor away from the rear axle of the trailer,~in or~er ~ :-to meet legal load limitations on ~he various axles and toimprove handling of the tractor~ The devices in question are embodied by pneumatic means exerting upward force~n the forward end of the trailer. Till now, such devices have been located forwardly of the fifth wheel of the tractor.
However, it is not always advantageous to shift weight away from the driving wheels of the tractor. For example, a tractor trailer unit travelling on a rough dirt or sand forest road with insufficient weLght on the driving wheels of~the tractor~may undergo wheel jumping and/or dif-ferential breakdown. Poor traction is also produced on snow- or ice-covered roads, or on forest ro~ds. Poor traction necessitates the use of~e~ply-grooved tires which are expenslvej ox~chains which are time-consuming to Ln~tall and remove.
OBJECTS OF~ ~THE~ INVENTION
~ In view o the above, it is a prime~object of the present invention to provIde~a weight~transer device which avoids the~above problems. ~ ~ ~
~It~is another~object of the~present invention to prov~de a we~ght transfer dev~ce~of the~character described, whlch ~s~simple~ln~des~gn~and whiah will~fit aLl tractors.
SUMMARY~ OF~THE INVENTION
The~above and other advantages o~ the present ~ `
~Z4~SZ
invention are realized according to a preferred embodiment comprising an upward ~orce-producing means, preferably a vertically-expandable air bag which can be quickly exhausted on rough roads. A frame means is provided to support the force-producing means and to secure the latter to the rearward frame members of the tractor. The force-producing means is located no more than six inches rearwardly of the rearmost driving wheels of the tractor and behind the fifth wheel of the tractor. The top of the force-producing means has secured thereto a rotation plate provided with an antifriction means to allow lateral pivotal motion of the trailer about its kingpin relative to the tractor. The frame means serves also to stabilize the force-producing means, as will be disclosed below.
Controls for the force-producing means are preferably located in the tractor cab.
BRIEF DESCRIPTION OF THE DRAWINGS
The above will be more clearly understood by having referral to the preferred embodiment of the invention, illus-~0 trated by way of the accompanylng drawings, in which:
Figure 1 is a perspective view of the inventioninstalled on a tractor frame; and Figure 2 is a~side elevation of the invention, showing a tractor trailer unit in dashed outline.
Like numerals refer to like elements throughout the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
~ ~ .
~ In the~figures, the weight transfer device of the prèsent inventlon, indicated~at lj is installed at the rear portion of a~tractor 2. ~The latter includes a pair of rear-wardly-extending~pa~rallel frame msmbers 3, 4, cab 5, rear driving wheels~6, 7j and;a fifth wheel 8.
,s~
~ ~4~3S~
To the top of both frame members 3 and 4 are fixed inclined ramps 9, 10 to facilitate hitching of trailer 11 to tractor 2.
The frame of device 1 consists of a pair of paxallel transverse mounting bars 12 and 13, each secured at their opposite ends to fastening members 14 (only one being visible).
Members 14 are bolted at 15, or otherwise rigidly secured to the adjacent frame members 3 and 4. The middle portions of mounting bars 12 and 13 have rigidly secured thereto a supporting plate 16. Seated on the latter is a vertically-expandable air bag 17, which is fed by a compressed-air line 18. Controls in the cab (not shown) operate the air bag.
Secured to the upper end of the air bag 17 is a rotation plate 19, which has a forward edge 19'. Forward ~. , edge 19' has rigidly secured thereto~a pair of laterally-spaced brackets 20. Pivotally secured to each of the latter at 20a is a rigid stabillzing arm 21. The~middle portions of arms 21 are reinforced by a brace 22. The forward ends of arms 21 are pivotally attached~at 24 to lugs or brackets 25, in turn fixed to a transverse~member,23, the latter~
extending between ramps 9,~10 and frame memb~ers 3, 4 and releasably secured to the latter by lugs 9-i, lO'.~ Elements 20, 21, 22, 23,~24, and~;25~constitute~the~rest of the frame means.
~ As shown;in figure 2, each upwardly- forwardly--inclined ramp 9, lO~pre~ferably extends between the;~horizontal;plane=
defined by the~support pl=te~16 and~the~rot=tion~plate l9,~ at least when the ~expandab~le air bag~l7~ }s inflated~to its ~
operàtive conditian~of figure 2 via,pressurized~air~line 18.
Device l further consists ¢f~a pair of rollers 26 and 27.~These two rollers are each disposed along a respective radial~line extending from the center of the i~th wheel.
s~
Thus, as the trailer pivots about its kingpin when the air bag is operating, the rollers will engage a rigid wear-plate (not shown) fixed to the underside of the trailer to provide substantially frictionless contact between tractor 2 and trailer 11 during a turn.
The rollers embody the antifriction means. Pivotal connections 20a and 24 are parallel,horizontal and transverse of the truck. They allow rollers 26 to always be applied flat against ~he trailer wear-plate, despite changes in road inclination.
It will be readily apparent that, as the pressure exerted by the air bag is increased, the load exerted by the trailer is adjustably and partially trans-ferred rearwardly from the fifth wheel over the driving axle~(s~ of the tractor. The air bag is adapted to exert up to 10,000 pounds of force on the trailer.
It is to be noted that the improved tractor obtained by the device is not at the expense of~a weakened tractor frame. The device is easy to install and remove.
;~ - ' :
" f : ' ' ~ ;
The present invention relates generally to devices adapted to distribute the weight of a tractor trailer more efficaciously.
BACKGROUND OF THE INVENTION
It is very well known in the art to provide devices of the above type. The desired effect o such devices is to shift weight to the front axle of the tractor away from the rear axle of the trailer,~in or~er ~ :-to meet legal load limitations on ~he various axles and toimprove handling of the tractor~ The devices in question are embodied by pneumatic means exerting upward force~n the forward end of the trailer. Till now, such devices have been located forwardly of the fifth wheel of the tractor.
However, it is not always advantageous to shift weight away from the driving wheels of the tractor. For example, a tractor trailer unit travelling on a rough dirt or sand forest road with insufficient weLght on the driving wheels of~the tractor~may undergo wheel jumping and/or dif-ferential breakdown. Poor traction is also produced on snow- or ice-covered roads, or on forest ro~ds. Poor traction necessitates the use of~e~ply-grooved tires which are expenslvej ox~chains which are time-consuming to Ln~tall and remove.
OBJECTS OF~ ~THE~ INVENTION
~ In view o the above, it is a prime~object of the present invention to provIde~a weight~transer device which avoids the~above problems. ~ ~ ~
~It~is another~object of the~present invention to prov~de a we~ght transfer dev~ce~of the~character described, whlch ~s~simple~ln~des~gn~and whiah will~fit aLl tractors.
SUMMARY~ OF~THE INVENTION
The~above and other advantages o~ the present ~ `
~Z4~SZ
invention are realized according to a preferred embodiment comprising an upward ~orce-producing means, preferably a vertically-expandable air bag which can be quickly exhausted on rough roads. A frame means is provided to support the force-producing means and to secure the latter to the rearward frame members of the tractor. The force-producing means is located no more than six inches rearwardly of the rearmost driving wheels of the tractor and behind the fifth wheel of the tractor. The top of the force-producing means has secured thereto a rotation plate provided with an antifriction means to allow lateral pivotal motion of the trailer about its kingpin relative to the tractor. The frame means serves also to stabilize the force-producing means, as will be disclosed below.
Controls for the force-producing means are preferably located in the tractor cab.
BRIEF DESCRIPTION OF THE DRAWINGS
The above will be more clearly understood by having referral to the preferred embodiment of the invention, illus-~0 trated by way of the accompanylng drawings, in which:
Figure 1 is a perspective view of the inventioninstalled on a tractor frame; and Figure 2 is a~side elevation of the invention, showing a tractor trailer unit in dashed outline.
Like numerals refer to like elements throughout the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
~ ~ .
~ In the~figures, the weight transfer device of the prèsent inventlon, indicated~at lj is installed at the rear portion of a~tractor 2. ~The latter includes a pair of rear-wardly-extending~pa~rallel frame msmbers 3, 4, cab 5, rear driving wheels~6, 7j and;a fifth wheel 8.
,s~
~ ~4~3S~
To the top of both frame members 3 and 4 are fixed inclined ramps 9, 10 to facilitate hitching of trailer 11 to tractor 2.
The frame of device 1 consists of a pair of paxallel transverse mounting bars 12 and 13, each secured at their opposite ends to fastening members 14 (only one being visible).
Members 14 are bolted at 15, or otherwise rigidly secured to the adjacent frame members 3 and 4. The middle portions of mounting bars 12 and 13 have rigidly secured thereto a supporting plate 16. Seated on the latter is a vertically-expandable air bag 17, which is fed by a compressed-air line 18. Controls in the cab (not shown) operate the air bag.
Secured to the upper end of the air bag 17 is a rotation plate 19, which has a forward edge 19'. Forward ~. , edge 19' has rigidly secured thereto~a pair of laterally-spaced brackets 20. Pivotally secured to each of the latter at 20a is a rigid stabillzing arm 21. The~middle portions of arms 21 are reinforced by a brace 22. The forward ends of arms 21 are pivotally attached~at 24 to lugs or brackets 25, in turn fixed to a transverse~member,23, the latter~
extending between ramps 9,~10 and frame memb~ers 3, 4 and releasably secured to the latter by lugs 9-i, lO'.~ Elements 20, 21, 22, 23,~24, and~;25~constitute~the~rest of the frame means.
~ As shown;in figure 2, each upwardly- forwardly--inclined ramp 9, lO~pre~ferably extends between the;~horizontal;plane=
defined by the~support pl=te~16 and~the~rot=tion~plate l9,~ at least when the ~expandab~le air bag~l7~ }s inflated~to its ~
operàtive conditian~of figure 2 via,pressurized~air~line 18.
Device l further consists ¢f~a pair of rollers 26 and 27.~These two rollers are each disposed along a respective radial~line extending from the center of the i~th wheel.
s~
Thus, as the trailer pivots about its kingpin when the air bag is operating, the rollers will engage a rigid wear-plate (not shown) fixed to the underside of the trailer to provide substantially frictionless contact between tractor 2 and trailer 11 during a turn.
The rollers embody the antifriction means. Pivotal connections 20a and 24 are parallel,horizontal and transverse of the truck. They allow rollers 26 to always be applied flat against ~he trailer wear-plate, despite changes in road inclination.
It will be readily apparent that, as the pressure exerted by the air bag is increased, the load exerted by the trailer is adjustably and partially trans-ferred rearwardly from the fifth wheel over the driving axle~(s~ of the tractor. The air bag is adapted to exert up to 10,000 pounds of force on the trailer.
It is to be noted that the improved tractor obtained by the device is not at the expense of~a weakened tractor frame. The device is easy to install and remove.
;~ - ' :
" f : ' ' ~ ;
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A weight transfer device for a tractor trailer, said tractor having a pair of rearward parallel frame members and a fifth wheel, comprising: an upward vertically-expandable air bag located between said frame members at the rear portion of the latter and behind the fifth wheel of said tractor; a pair of mounting bars, transversely secured to the rear portions of both frame members; a support plate, rigidly secured to said mounting bars and to the lower end of said air bag, to support the latter; a rotation plate, secured to the top end of said air bag; a transverse member rigidly secured to said frame members forwardly of said air bag; and at least one longitudinal stabilizing arm, pivotally secured by first and second pivot members to said rotation plate and to said transverse member, res-pectively; anti-friction means between the top of said air bag and the lower surface adjacent thereto of said trailer, whereby actuation of said air bag transfers weight from said fifth wheel rearwardly over the traction wheels of said tractor;.
2. A weight transfer means as defined in claim 1, wherein there are two of said stabilizing arms.
3 A weight transfer means as defined in claim 2, wherein said anti-friction means consists of a pair of rollers mounted on top of said rotation plate and each, disposed along a radial line extending from the center of said fifth wheel.
4. A weight transfer device as defined in claim 3, wherein each frame member is provided with an upwardly-forwardly-inclined ramp forwardly of said rotation plate.
5. A weight transfer device as defined in claim 1, wherein said first and second pivot members define pivotal axes which are parallel, horizontal, and transverse to the longitudinal axis of the truck.
6. A weight transfer device as defined in claim 4, wherein each said upwardly- forwardly-inclined ramp extends between the horizontal planes defined by said support plate and said rotation plate, at least when said expand-able air bag is inflated to its operative condition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000530783A CA1244852A (en) | 1987-02-27 | 1987-02-27 | Weight transfer device for tractor trailer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000530783A CA1244852A (en) | 1987-02-27 | 1987-02-27 | Weight transfer device for tractor trailer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1244852A true CA1244852A (en) | 1988-11-15 |
Family
ID=4135064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000530783A Expired CA1244852A (en) | 1987-02-27 | 1987-02-27 | Weight transfer device for tractor trailer |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1244852A (en) |
-
1987
- 1987-02-27 CA CA000530783A patent/CA1244852A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |