IE72497B1 - A semi-trailer command steering system - Google Patents
A semi-trailer command steering systemInfo
- Publication number
- IE72497B1 IE72497B1 IE940952A IE940952A IE72497B1 IE 72497 B1 IE72497 B1 IE 72497B1 IE 940952 A IE940952 A IE 940952A IE 940952 A IE940952 A IE 940952A IE 72497 B1 IE72497 B1 IE 72497B1
- Authority
- IE
- Ireland
- Prior art keywords
- king pin
- ram
- cylinder
- trailer
- master
- Prior art date
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- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
A command steering system for a semi-trailer of the type having a wheeled chassis having a king pin and associated rubbing plate at a front of the trailer for engagement with the fifth wheel coupling on a tractor vehicle. The system (1) has a king pin (3) which is rotatably mounted on the trailer. The king pin (3) is connected to a control ram (11) for directing hydraulic fluid to a slave ram (18) for operating the slave ram (18) to steer wheels (22) on the trailer.
Description
A Semi-Trailer Command Steering System
This invention relates to a semi-trailer command steering system for positively steering wheels on the semi-trailer.
In a known semi-trailer steering system a turntable is provided in place of the standard rubbing plate assembly. The turntable is connected to a steering controller comprising rams which detect the turning of a tractor vehicle relative to the trailer. These turntable rams are connected to associated rams in the axle steering system which control a steering linkage to turn the wheels on the axle. This known system is of relatively complicated construction and is both expensive to produce and adds a considerable weight to the trailer.
The present invention is directed towards overcoming these problems .
The invention consists essentially in providing a rotatable kingpin on a trailer which is used to control a steering axle assembly on the trailer.
According to the invention there is provided a command steering system for a semi-trailer of the type comprising a wheeled chassis and having a king pin and associated rubbing plate at a front of the chassis for complementary releasable engagement with a fifth wheel coupling on a tractor vehicle, the command steering system comprising at least one steering axle for mounting on the chassis, a king pin which is rotatably mounted on the semi-trailer chassis, the king pin rotatably mounted in a housing by means of a bearing, the king pin having a tongue for engagement with the fifth wheel coupling of the tractor vehicle for releasably locking the king pin in engagement with the fifth wheel coupling while allowing rotation of
4 9 7
- 2 the king pin on the semi-trailer, a master ram mounted on the trailer chassis, the king pin being connected to the master ram for operation of the master ram in response to rotation of the king pin on the semi-trailer, the master ram being connected to a complementary slave ram mounted at the steering axle for operation of the slave ram to turn wheels on the steering axle, the slave ram being connected to the wheels for turning the wheels on the steering axle to steer the wheels as the trailer turns.
In one embodiment of the invention, the slave ram comprises a double-acting ram mounted on the steering axle, the slave ram having a cylinder mounted on the steering axle with an associated piston mounted within the cylinder on a piston rod which projects outwardly at both ends of the cylinder, each end of the piston rod being connected to steering arms on the steering axle for turning the wheels on the steering axle.
Preferably, the cylinder is pivotally mounted on the steering axle and is slidable perpendicularly to the axis of the steering axle.
Preferably, the master ram and slave ram are operable to turn the wheels on the steering axle in the opposite direction to the tractor vehicle.
In another embodiment the master ram comprises a cylinder part and a piston part, the king pin being connected to one part for moving said part relative to the other part in response to king pin rotation on the trailer.
In a further embodiment the piston part is slidable relative to the cylinder part along an axis which is substantially parallel to the rotational axis of the king pin.
In another embodiment the king pin is connected to the master ram by a cam means for operation of the master ram.
In another embodiment the cam means comprises a circumferential cam surface on the king pin which engages with one or more radially arranged rams forming the master ram for operation of said master ram.
In another embodiment the cam means comprises a flanged cam plate on the king pin having a cam surface on a face of the cam plate which engages one or more rams forming the master ram for operation of said master ram.
In another embodiment the cam means comprises a sleeve coaxially mounted fast on the king pin, the sleeve having a cam groove on its outer surface, a cam follower engaging in the groove and connected to the master ram for sliding the piston part relative to the cylinder part in response to rotation of the king pin on the trailer.
In another embodiment the cam follower is connected to the cylinder part.
In another embodiment the cylinder part is mounted between spaced-apart end plates, a pair of pistons projecting outwardly at opposite ends of the cylinder part to abut the end plates, axial movement of the cylinder relative to said end plate operating the master ram.
In another embodiment an annular cylinder is provided with associated annular pistons.
In another embodiment the king pin is connected to the master ram by a screw movable axially on the king pin in response to rotation of the king pin for operation of the master ram.
In another embodiment the master ram comprises a cylinder having a diaphragm mounted within the cylinder dividing the cylinder into two fluid chambers, the master ram being connected to the king pin for flexing the diaphragm in response to rotation of the king pin for operation of the master ram.
In another embodiment the cylinder is mounted on the king pin, the king pin passing centrally through the cylinder and the diaphragm, an outer periphery of the diaphragm being fixed to a side wall of the cylinder, a central portion of the diaphragm being attached to a sleeve which is mounted on the king pin, the sleeve being connected to the king pin for movement along the king pin in response to rotation of the king pin.
In another embodiment the master ram is a double-acting ram having a cylinder with a piston mounted on a piston rod which projects outwardly of the cylinder, the piston rod being attached to a laterally extending arm on the king pin for movement of the piston through the cylinder in response to rotation of the king pin.
The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which :Fig. 1 is a schematic illustration of a semi-trailer command steering system according to the invention;
Fig. 2 is an elevational view of portion of the steering system;
Fig. 3 is a view similar to Fig. 2 of portion of another semi-trailer command steering system; and
Fig. 4 is a side elevational view of a trailer incorporating a steering system according to the invention;
Fig. 5 is a perspective view of a master ram forming portion of another semi-trailer command steering system;
Fig. 6 is an elevational view of the master ram of Fig. 5;
Fig. 7 is a sectional elevational view of the master ram of the Fig. 5;
Fig. 8 is an exploded perspective view of the master ram of Fig. 5;
Fig. 9 is another exploded perspective view of the master ram of Fig. 4;
Fig. 10 is an elevational view of a sleeve portion of the master ram;
Fig. 11 is a schematic sectional elevational view of a slave ram forming portion of the semi-trailer command steering system;
Fig. 12 is a perspective view showing the slave ram of Fig. 11 mounted on a trailer axle assembly; and
Figs. 13 - 16 are schematic illustrations showing examples of alternative methods of operating the steering controller by means of the rotatable king pin.
Referring to the drawings, and initially to Figs. 1 and 2 thereof, there is illustrated a semi-trailer axle steering system according to the invention indicated generally by the numeral 1. The system 1 has a turn detector 2 mounted on a kingpin 3 of a trailer to which the system 1 is fitted. The kingpin 3 is rotatably mounted in a housing 4 by means of bearings 5. A tongue or wedge 15 is mounted on the kingpin 3 for engagement with the fifth wheel coupling of the tractor vehicle to hold the kingpin 3 fast to the tractor vehicle.
The turn detector 2 comprises an arm 6 splined or keyed onto an upper end 7 of the kingpin 3. At an outer end 8 of the arm 6 a rod 9 is pivotally attached by a pivot pin
. The rod 9 forms portion of a steering controller formed by a double acting master ram 11 and passes through a cylinder 12 and carries a piston 13 within the cylinder
12. Suitable seals 14 are provided at each end of the cylinder 12 where the rod 9 projects through the cylinder 12. It will be noted that as the rod 9 passes through the cylinder 12 the effective area on each side of the piston 13 is the same, A slave ram 18 of similar construction to the master ram 11 is provided adjacent a steer axle 20 assembly of the trailer. The axle assembly 20 has steering arms 21 connected to wheels 22. A steering link rod 23 interconnects the arms 21. A rod 25 of the slave ram 18 is connected to one of the steering arms 21 to turn the wheels 22 together.
In use, with the trailer attached to a tractor vehicle, if the tractor vehicle turns the kingpin 3 will also turn thus moving the arm 6 which slides the piston 13 within the cylinder 12. Hydraulic fluid within the cylinder 12 is pressurised on one side of the piston 13 and is delivered to the slave ram 18 to provide a complementary movement of the rod 25 for steering the wheels 22 as the trailer turns. The wheels 22 will turn in the opposite direction to the tractor vehicle.
It will be appreciated that the invention provides a steering system of relatively simple construction comprising essentially of a rotatable kingpin on a trailer being used to control a steering axle assembly on the trailer.
Fig. 3 shows a rotating kingpin assembly 40 of another trailer steering system. In this case a kingpin 41 is rotatably supported in a housing 42 by tapered roller bearings 43.
Referring now to Figs. 4 to 12 there is illustrated another semi-trailer command steering system indicated generally by the reference numeral 50. A semi-trailer 30 is shown in Fig. 4 comprising a wheeled chassis 31. A rubbing plate 32 is provided at a front of the chassis 31 for engagement with a fifth wheel coupling of a tractor vehicle. The system 50 comprises a master ram 51 mounted above the rubbing plate 32 incorporating a rotatable king pin 54 which projects below the rubbing plate 32 and an associated slave ram 52 mounted on a trailer axle 53 for turning wheels 22 mounted on the axle 53.
The master ram 51 has a rotatable king pin 54 with associated tongue 55 for interlocking engagement with the fifth wheel coupling on a tractor vehicle.
The ram 51 has a lower mounting ring 57 which is generally welded to an upper face of the rubbing plate 32 of the
- 8 trailer 30. A pair of end plates 59,60 are mounted by means of bolts 61 to the mounting plate 57, the bolts 61 passing through holes in the plates 59,60 and engaging threaded holes 62 in the mounting plate 57. The plates 59,60 are spaced-apart by a pair of spacer blocks 64 mounted at opposite sides of the plates 59,60. An hydraulic cylinder block 66 is mounted between the plates 59,60. Two concentric sets of annular pistons 67,68 are slidably mounted in associated annular sockets in opposite ends of the cylinder block 66 effectively forming four hydraulic cylinders. Hydraulic pipes 74 connecting with each of the cylinders project outwardly of the cylinder block 66. Hydraulic pressure will keep the pistons 67,68 held against inner faces of the plates 59,60 while the cylinder block 66 can be raised and lowered in response to rotation of the king pin 54 to alter the volume of the cylinders thus directing hydraulic fluid to the slave ram 52 for operation of the slave ram 52. Each end plate 59,60 has a recessed minor edge 76,77 for mounting a cover (not shown) between the end plates 59,60. The king pin 54 is rotatably mounted in a centrally located bearing 78 on the lower end plate 59.
The king pin 54 has a splined portion 80 which drivably engages a cylinder control collar 81 secured on the splines by means of a retaining nut 82 which engages a threaded end 83 of the king pin 54. A helical groove 85 are provided in an outer surface of the collar 81. These grooves 85 are engaged by a pair of rods 86 forming cam followers which project inwardly through complementary slots in the cylinder block 66. The rods 86 project outwardly of the cylinder block 66 and slidably engage grooves 88 in the spacer blocks 64. Thus, upon rotation of the king pin 54, the collar 81 rotates each of the rods 86 run in the grooves 85 and depending on the direction of rotation of the king pin 54 thus raise or lower the cylinder 66 to operate the ram 51.
A plug 90 sits in upper end of the sleeve 81 and engages the top plate 60 to prevent sideways movement of the sleeve 81. The sleeve 81 and plug 90 locate within a central control opening 91 of the cylinder 66.
Referring to Fig. 11, the slave ram 52 is shown. This comprises an outer cylindrical body 95 through which a piston rod 96 passes. The body 95 is centrally divided by a trunnion 97 into two parts. Within each part a piston 99 mounted on the piston rod 96 divides each part into a pair of hydraulic cylinders. Ports 100 of each cylinder connect to the hydraulic pipes 74 of the cylinder 66. Free ends of the piston rod 96 connect to steering arms 102 of the axle assembly 53. The trunnion 97 is supported between a pair of mounting brackets 105 on the axle 53. A slot 106 in each bracket 105 allows forward movement of the trunnion 97 and rotational movement of the trunnion to accommodate movement of the ram 52 when steering wheels on the axle 53.
In use, the king pin 54 locks with the fifth wheel coupling on a tractor vehicle such that it will turn with the tractor vehicle. As the king pin 54 turns the ram 51 operates to direct hydraulic fluid to associated cylinders in the slave ram 52 for lateral movement of the piston rod 96 for controlled steering of the wheels on the axle 53.
It will be appreciated that in the embodiment described two ram sets are provided at the steering controller and at the steering axle, one set of providing backup in case of failure of the other ram set.
Fig. 13 shows an alternative steering controller 120 operated by a rotatable king pin 54. The steering controller 120 has a cylinder 121 through which the king pin 54 passes. A piston 122 is mounted on the king pin 54 by means of a collar 123. The collar 123 is attached to the king pin 54 by a screw thread such that upon rotation of the king pin 54 the collar moves axially along the king pin for moving the piston 122 within the cylinder 121 to control the steering.
Referring now to Fig. 14 another steering controller 130 is shown. In this case, a circumferential cam 131 on the king pin 54 with radially arranged pistons 132 in associated cylinders 133 for controlling the steering.
Referring now to Fig. 15 there is illustrated another steering controller 140. In this case a flanged cam plate 141 on the king pin 54 has cam formations 142 on a surface of the plate 141. The cam formations 142 move pistons 143 within associated cylinders 144 upon rotation of the king pin 54 for controlling hydraulic fluid supply to the steering axle.
Referring now to Fig. 16 there is illustrated another steering controller 150. The controller 150 comprises a cylinder 151 through which the king pin 54 passes. A diaphragm 152 is mounted between the king pin 54 and cylinder 151. An outer edge of the diaphragm 152 is clamped at the cylinder sidewall. An inner end of the diaphragm 152 is mounted on a sleeve 155 which is axially movable along the king pin 54 in response to rotation of the king pin 54. Movement of the diaphragm 152 directs oil between the controller 150 and the steering axle for controlling the steering axle.
It is envisaged that instead of having a rotatable kingpin on the trailer a similar effect could be created by having a fixed kingpin carrying a rotatable sleeve engagable with the fifth wheel coupling of a tractor vehicle to detect relative turning of the tractor and trailer and control trailer steering.
It is envisaged that a similar device could be used for command steer of a draw bar type trailer.
Claims (17)
1. A command steering system for a semi-trailer of the type comprising a wheeled chassis and having a king pin and associated rubbing plate at a front of the chassis for complementary releasable engagement with a fifth wheel coupling on a tractor vehicle, the command steering system comprising at least one steering axle for mounting on the chassis, a king pin which is rotatably mounted on the semi-trailer chassis, the king pin rotatably mounted in a housing by means of a bearing, the kin pin having a tongue for engagement with the fifth wheel coupling of the tractor vehicle for releasably locking the king pin in engagement with the fifth wheel coupling while allowing rotation of the king pin on the semitrailer, a master ram mounted on the trailer chassis, the king pin being connected to the master ram for operation of the master ram in response to rotation of the king pin on the semi-trailer, the master ram being connected to a complementary slave ram mounted at the steering axle for operation of the slave ram to turn wheels on the steering axle, the slave ram being connected to the wheels for turning the wheels on the steering axle to steer the wheels as the trailer turns.
2. A system as claimed in claim 1 wherein the slave ram comprises a double-acting ram mounted on the steering axle, the slave ram having a cylinder mounted on the steering axle with an associated piston mounted within the cylinder on a piston rod which projects outwardly at both ends of the cylinder, each end of the piston rod being connected to steering arms on the steering axle for turning the wheels on the steering axle.
3. A system as claimed in claim 2 wherein the cylinder is pivotally mounted on the steering axle and is slidable perpendicularly to the axis of the steering axle.
4. A system as claimed in any preceding claim wherein the master ram and slave ram are operable to turn the wheels on the steering axle in the opposite direction to the tractor vehicle.
5. A system as claimed in any preceding claim wherein the master ram comprises a cylinder part and a piston part, the king pin being connected to one part for moving said part relative to the other part in response to king pin rotation on the trailer.
6. A system as claimed in claim 5 wherein the piston part is slidable relative to the cylinder part along an axis which is substantially parallel to the rotational axis of the king pin.
7. A system as claimed in any preceding claim wherein the king pin is connected to the master ram by a cam means for operation of the master ram.
8. A system as claimed in claim 7 wherein the cam means comprises a circumferential cam surface on the king pin which engages with one or more radially arranged rams forming the master ram for operation of said master ram.
9. A system as claimed in claim 7 wherein the cam means comprises a flanged cam plate on the king pin having a cam surface on a face of the cam plate which 14 engages one or more rams forming the master ram for operation of said master ram.
10. A system as claimed in claim 7 wherein the cam means comprises a sleeve co-axially mounted fast on the king pin, the sleeve having a cam groove on its outer surface, a cam follower engaging in the groove and connected to the master ram for sliding the piston part relative to the cylinder part in response to rotation of the king pin on the trailer.
11. A system as claimed in claim 10 wherein the cam follower is connected to the cylinder part.
12. A system as claimed in claim 11 wherein the cylinder part is mounted between spaced-apart end plates, a pair of pistons projecting outwardly at opposite ends of the cylinder part to abut the end plates, axial movement of the cylinder relative to said end plate operating the master ram.
13. A system as claimed in any of claims 10 to 12 wherein an annular cylinder is provided with associated annular pistons .
14. A system as claimed in any of claims 1 to 6 wherein the king pin is connected to the master ram by a screw movable axially on the king pin in response to rotation of the king pin for operation of the master ram.
15. A system as claimed in any of claims 1 to 6 wherein the master ram comprises a cylinder having a diaphragm mounted within the cylinder dividing the cylinder into two fluid chambers, the master ram being connected to the king pin for flexing the diaphragm in response to rotation of the king pin for operation of the master ram.
16. A system as claimed in claim 15 wherein the cylinder is mounted on the king pin, the king pin passing 5 centrally through the cylinder and the diaphragm, an outer periphery of the diaphragm being fixed to a side wall of the cylinder, a central portion of the diaphragm being attached to a sleeve which is mounted on the king pin, the sleeve being connected to the 10 king pin for movement along the king pin in response to rotation of the king pin.
17. A system as claimed in any of claims 1 to 6 wherein the master ram is a double-acting ram having a cylinder with a piston mounted on a piston rod which 15 projects outwardly of the cylinder, the piston rod being attached to a laterally extending arm on the king pin for movement of the piston through the cylinder in response to rotation of the king pin.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IE940952A IE72497B1 (en) | 1993-12-03 | 1994-12-05 | A semi-trailer command steering system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IE930936 | 1993-12-03 | ||
IE940952A IE72497B1 (en) | 1993-12-03 | 1994-12-05 | A semi-trailer command steering system |
Publications (2)
Publication Number | Publication Date |
---|---|
IE940952A1 IE940952A1 (en) | 1995-06-14 |
IE72497B1 true IE72497B1 (en) | 1997-04-23 |
Family
ID=26319664
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
IE940952A IE72497B1 (en) | 1993-12-03 | 1994-12-05 | A semi-trailer command steering system |
Country Status (1)
Country | Link |
---|---|
IE (1) | IE72497B1 (en) |
-
1994
- 1994-12-05 IE IE940952A patent/IE72497B1/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
IE940952A1 (en) | 1995-06-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
FK9A | Application deemed to have been withdrawn section 23(9) | ||
MM4A | Patent lapsed |