FR2498138A1 - DEVICE FOR ACTUATING A TRAIN OF SUPPORTS, IN PARTICULAR FOR SEMI-TRAILERS - Google Patents

Abstract

The invention relates to a device for actuating a support train, in particular for semi-trailers. IN THIS ACTUATOR 10 FOR A TRAILER OF SEMI-TRAILER SUPPORTS HAVING TWO ARMS 14 THAT CAN BE DEPLOYED OR RETRACTED AND A TRANSVERSAL SHAFT 17 EXTENDING BETWEEN THESE LATTERS, PROJECTING LATERALLY BEYOND A FOOT AND CAN BE MANEUVER SO AS TO DEPLOY OR RETRACT THE SAID ARMS 14 ACCORDING TO ITS DIRECTION OF ROTATION, A CRANKCASE 30 IS PROVIDED FOR A ROTATING BODY, MEANS 31 FOR MOUNTING THIS CRANKCASE NEAR ONE OF THE ARMS, MEANS FOR CONNECTING THE 'ROTATING ORGAN WITH CROSS-SHAFT 17 OUTSIDE ARM 14 AND MECHANICALLY ACTUATED MEANS AND CARRIED BY CRANKCASE 30 TO DRIVE THE ROTATING ORGAN IN ROTATION. APPLICATION ESPECIALLY TO TRAILER VEHICLES AND SEMI-TRAILERS.

Description

The present invention relates to an actuating device for the train

  of trailer supports of a combined vehicle tractor trailer. Usually such a trailer has two laterally spaced brackets of the support train which extend downward from the front of the trailer and contact the ground to support the trailer in an elevated position.

  when the latter is detached from the towing vehicle.

  When the trailer is coupled to the towing vehicle, the legs of the support train are retracted upwards.

  way that they do not contact the ground, whereas

  Morque is pulled by the towing vehicle.

  In most trailers, the legs of the support train are connected by a laterally extending transverse shaft that spreads the feet as it pivots in one direction and retracts the feet as it pivots in the opposite direction. The transverse shaft is usually connected to a two-speed gearbox located on the outside of one of the feet and can be rotated optionally at a high speed or at a low speed by means of a gearbox. crank operated manually and

  attached to the input shaft of the gearbox.

  It was felt that manual actuation of

  It takes a considerable time and requires considerable effort. For this reason, actuators actuated by a motor have been provided for pivoting the transverse shaft in either direction so as to extend or retract the legs of the support train. Such a device for actuating the support train, controlled by a motor, is described in the patent

  of United States of America No. 4,116,315 and uses a

  reciprocating pneumatic actuating device, which is controlled by the same source of compressed air as that used to actuate the brakes of the combined tractor-trailer combination. Another actuation device

  sunrift train, at the regional level, was co-sponsored

  made by Northwest Manufacturing Corporation of Camanche (Iowa, United States of America) under the trademark "GEAR MATE". This actuating device comprises a gear box with two speeds making it possible to rotate the transverse shaft at a high speed.

or at a low speed.

  The general object of the present invention is to provide a novel and improved actuation device

  of the support train which, compared to earlier

  It can be installed faster and more conveniently on the trailer and at the same time is more compact, lightweight, reliable and economical. In more detail, an object of the invention is to provide a device for actuating the support train, which is able to be easily mounted on the trailer without requiring first a removal, then a

  replace one of the feet of the support train.

  Another object of the invention is to provide a device for actuating the support train, able to pivot the transverse shaft either at high speeds or at low speeds without requiring the incorporation of a gear box. two-speed gears in the device

actuation itself.

  Another object of the invention is to achieve

  the objectives indicated above, by a simple connection

  the actuating device of the support train directly to the existing crank shaft of the trailer and using the existing gearbox of the

  trailer to enable the drive

  drag in rotation the transverse shaft either at speeds

  high, or at slow speeds.

  Another object of the invention is to provide a

  actuating device of a support train, in the-

  the reciprocating movement of the pneumatic actuator is converted into a rotational movement solely by means of a relatively compact construction of ratchet wheels, pawls and gears

and simple.

  The invention also consists in providing for new

  means for actuating and deactivating the pawls so that the reciprocating pneumatic actuator can selectively pivot the cross shaft in either direction.

  Other objects of the present invention are

  to provide a cyclic operating valve, extremely

  reliable and effective, with a view to achieving a reversal

  automatic and cyclic operation of the pneumatic actuator

  with reciprocating movement, to provide a

  reliable control that can be operated by hand to achieve

  connect and unplug the device

  of actuation, and to provide a control valve which de-

  automatically connect the actuating device when

  that the feet of the support train reach their positions

fully retracted.

  These objects as well as other objects and advantages of the present invention will become apparent from the

  detailed description which will follow considered in liaison

  with the accompanying drawings, in which - Figure 1 is a partial perspective view

  a typical trailer equipped with a new device

  designed to operate a train of

  the particular features of this invention

  tion; - Figure 2 is a cross-sectional view

  partial scale, taken in

  Fig. 3 is a cross-sectional view taken substantially along line 3-3 of Fig. 2 and showing the actuator set to retract the feet of the support train. ; FIG. 4 is a partial view of parts shown in FIG. 3 and shows some parts of the actuator in other positions, during the removal of the feet, FIG. 5 is a view similar to FIG. Figure 3 but showing the actuator set to extend the feet of the support train; FIG. 6 is a partial view of parts shown in FIG. 5 and shows certain parts of the

  actuating device in other positions, when

  that the feet are deployed; - Figures 7 and 8 are sectional views

  partial cross-section on a larger scale, taken

  following lines 7-7 and 8-8 of Figure 5; and FIG. 9 is a schematic view of the cyclic operating valve, the control valve and the pneumatic actuator and shows the circuit

tire associated with them.

  As shown in the figures for purposes of illustration, the invention is implemented in an actuating device 10 intended to deploy and to

  retract the trailer support train there from a

  seems combined tractor-trailer vehicle (ie a semi-trailer). The support train is part of the

  trailer itself and has two skates or feet 12 dis-

  laterally. These are mounted to

  able to pivot on the lower ends of

  14 which are slidably housed in vertical sleeves 15 secured by mounting brackets 16 at the front end of the trailer. The feet and arms are retracted upwards when the trailer is coupled to the towing vehicle so as to prevent the

  feet do not touch the ground while towing the trailer.

  than. When the trailer must be uncoupled from the vehicle

  With the tractor, the feet and arms are extended downward to lift the trailer upward from the fifth wheel of the towing vehicle.

and leave the trailer alone.

  A rotary member constituted in the form of a

  transverse shaft 17 extends laterally between the

  15 near the upper end of the arms 14 and acts so as to deploy the arms when it pivots in one direction and to retract when it pivots in

  the opposite direction. Different types of mechanisms can

  work with the shaft to extend or retract the arms when the shaft is rotated. In this particular case, a nut 18 (FIG. 2) is fixed rigidly to the upper end of each arm and is screwed onto a lead screw.

  19 which is mounted in such a way as to

  15. Interengaging bevel gears 20 are attached to the shaft 17 and to the upper end of the screw 19 and rotate the screw in one direction.

  or in the other depending on the direction of rotation of the shaft.

  When the screws are turned, the nuts move downward or upward to extend or retract

arms.

  Conventionally, the transverse shaft 17 constitutes the output member of a gearbox 21 which is

  attached to the outside of one of the sleeves.

  the gearbox is formed by a crank shaft 22 (FIG. 2), extending outwardly and of which

  the inner end is in this case formed by a man-

  chon 23. The latter carries a large pinion 24 and a small pinion 25 and is mounted so as to slide on a shaft 26 inside the gearbox 21. When the crank shaft 22 is pushed towards the outside, the large pinion 24 meshes with a small pinion 27 located on the transverse shaft 17, as shown in Figure 2, so that when the crank shaft rotates to a

  given speed, the transverse shaft is rotated

  at a faster speed, but with a couple of

  relatively weak. This is the position setting to

  high speed of the gearbox 21, which is usually

  it is used to achieve a rapid withdrawal arms 14 when the trailer 11 must be lowered and the power required is low. When the arms must be deployed in such a way as to lift the

  trailer, the crank shaft 22 is pushed back inside-

  This is caused by causing the sleeve 23 to slip on the shaft 26 and causing the small pinion 25 situated on the sleeve to mesh with a large pinion 28 situated on the transverse shaft 17. During the rotation of the shaft 26 while the gearbox is at its lower speed setting, the transverse shaft is rotated at a relatively slow speed, but with

  a relatively high input torque so as to develop

  the power needed to deploy the arms and

  lift the trailer. In many trailers, a crank (no

  shown) is attached to the outer end of the

  crank 22 and can be turned by hand so as to rotate the transverse shaft 17 and to deploy and retract the arms 14. In order to avoid the expense from the time point of view and from the point of view of efforts, required to manually operate the crank, some trailers are equipped with actuators actuated by a motor, which are adapted to rotate the shaft

  transversal in one direction or the other so as to

  Automatic deployment and removal of arms.

  In one of its aspects, the present invention provides for the use of a new and improved mechanically controlled actuation device of the support train.

  characterized by the fact that the action device

  ment is attached to and acts directly on the tree to

  22, instead of being connected to the transverse shaft 17 at a certain point along the latter. As a result, the actuating device can be installed in an easily accessible location outside one of the arms 14 and can be mounted quickly on the trailer 11 without requiring the removal of the arm 14 and the sleeve 15. In addition, the actuating device 10 uses the existing gearbox 21 to provide a passage between a high speed setting and a low speed setting, and therefore the actuating device itself does not need to be cluttered with a separate transmission mechanism

at two speeds.

  More specifically, the action device

  10 comprises a housing 30 preferably disposed outside the gear box 21 and adapted to be rigidly attached to the adjacent sleeve 15 with a mounting bracket 31 (Figure 1). According to the present invention,

2498 138

  the outer end of the crankshaft 22 extends laterally through the side walls of the housing 30

  and terminates outside the outer sidewall.

  A sleeve 32 (FIG. 3) is telescopically mounted on the outer end of the crank shaft and is rigidly connected thereto by means of a pin 33 which extends radially through the sleeve and the shaft.

  crank. A pad 34 is firmly attached to the interior

  of the sleeve 32 and can rotate with the latter. The cushion lodges, with a game allowing a rotation, a

  coupling device 34a which is surrounded partially

  by a flexible protective cover 35. A lever of change

  speed assembly 37, which is rotatably connected in the vicinity of its center point, as indicated at 38, to the outer side wall of the housing 30,

  is connected with the possibility of pivoting and sliding

  36 at the lower end of the delivery device.

  34. When the shift lever pivots counterclockwise from the position shown in FIG. 2, it acts via the coupling device 34a, the bushing 34, the sleeve 32 and pin 33 for pushing the crank shaft 22 inwardly and adjusting the gearbox 21 at the reduced speed. Reverse pivoting of the lever adjusts the gearbox to its high speed as shown in FIG.

  because of the presence of the pad 34, the rotation of the armature

  crank 22 is not transmitted to the device

coupling 34a and the lever 37.

  In addition, according to the invention, a member (FIGS. 2 and 3) driven mechanically rotates via the pin 33 so as to rotate in one of the two directions the crankshaft 22, which acting through the gearbox 21 and the transverse shaft 17 so as to extend or retract the arms 14. In this case, the member 40 is formed in the form of a tubular hub disposed at The inner housing 30 is rotatably mounted in such a manner that bearing bearings 41 are carried by the side walls of the housing. The hub 40 is telescopically fitted onto the crankshaft 22 and the sleeve 32 and

  is provided with two slots or keyways 42 diametre

  The spindle and key grooves are axially opposed and accommodate the projecting ends of the spindle 33. Due to the presence of the spindle and the keyways, the rotation of the hub 40 is transmitted to the crankshaft 22. simultaneously, the crank shaft can slide axially relative to the hub when the lever 37 pivots to pass the gearbox 21

  from high speed to low speed.

  In accordance with the present invention, a gearwheel 44 (FIGS. 2 and 3) is attached to the hub and preferably is integral with the hub as shown in FIG. 2. A unidirectional ratchet wheel 45 (FIG. 3) is arranged next to the toothed wheel 44 and made in one piece with this wheel and the hub. Inside the casing 30 is disposed a second gear wheel 46 (FIG.

  3) which meshes with the wheel 44. A single ratchet wheel

  directional 47 is formed integrally with a face of the toothed wheel 46 and the two wheels are formed integrally with a hub 48 which is journalled so as to be pivotable in bushings 49 (Figure 1) supported by the side walls of the housing 30. The ratchet wheels 45 and 47 are arranged in a common plane and the teeth of each wheel are directed in

the same direction.

  With the ratchet wheels 45 and 47 coagulate

  ratchets 50 and 51 (FIG.

  each an edge with multiple teeth. Each guest

  quet is mounted on an alternating drive member 52 so as to move substantially tangentially with respect to the associated ratchet wheel. In addition, each pawl is rotatably mounted to the drive member by means of a journal pin 53 and is swingable up and down between active and inactive positions relative to the ratchet wheel. associated with it. When each pawl is tilted upward into its active position, its teeth contact

  the teeth of the associated ratchet wheel (for example, the

  quet 51 in Figure 4). The teeth of each pawl are released from the teeth of the ratchet wheel and spaced downwardly relative thereto when the pawl is tilted downwards to its inactive position, as

  is indicated for example by the pawl 50 in FIG.

  Leaf springs 54, mounted cantilevered, are dis-

  placed below the pawls and have free ends which bear against the lower faces of the pawls near the free ends of the latter so as to push the pawls upwards in their active position. The opposite end of each spring is anchored in the upper face of the lower part of the drive member 52. In this case, the driving member is in the form of a U-shaped profile, the bottom is carried by rollers 55 which extend between the side walls of the housing 30. The pawls are located between the side walls of the drive member 52 in the form of a U-shaped profile.

  Provision is made for communi-

  selectively latching each of the pawls 50 and 51 between its active and inactive positions, a pawl being brought into its active position when the other pawl is brought into its inactive position. In this case, these devices comprise the lever 60 (FIGS. 1 and 3), which is attached to a pin

  61 (Figures 3 and 7), which is carried with

  The outer end of the spindle protrudes outwardly through the outer side ply and is rigidly connected to an elongated handle 62 which forms a constituent part of the lever. As shown in FIG. 3, the lever 60 also includes two arms 63 and 64 extending into opaque diesels and are disposed above rollers 65 and 66 attached to the pawls and 51 and extending outwardly from of these. When the handle 62 is rotated counterclockwise to bring it into the position shown in FIG. 3, the arm 63 contacts the roller located on the pawl 50 and pushes the latter downwards in its direction. inactive position, the roller being received inside a notch 67 located in the outer face of the drive member 52. Simultaneously the arm 64 pivots upwardly away from the roller 66 located on the pawl 51 in order to allow the latter to rotate

  upward to come into his active position, being

  pushed by the underlying spring 54. The clockwise pivoting of the handle in the position shown in FIG. 5 causes the arm 64 to push the pawl 51 down to its inactive position and the arm 63 to allow the pawl 50 to pivot. elastically upward in its active position. If the handle 62 is centered between the represented positions

  in FIGS. 3 and 5, the arms hold the two

  50 and 51 in a neutral position, in which none of the pawls contact the ratchet wheel 45 or 47 which

  is associated. The handle can be maintained, with possibility

  releasing unit, in each of its positions by means of a latch which is here formed by two leaf springs 70

  (Figure 8). The springs are fixed at 71 to the side wall

  outer casing 30 and their lower ends

  laterally spaced, enclose the arm 63. The

  frictional contact between the springs 70 and the arm 63

  a holding force that holds the handle 62 in

  the position in which she rotated.

  To operate with a reciprocating motion

  the drive member 52, a pneumatic actuator

  73 is operatively connected to one end.

  mity of the drive member. In this case, the pneumatic actuating device comprises a cylinder 74 (Figures 1, 3 and 9) located outside the housing 30 and fixed to the front end thereof. A rod 75, one end protruding rearward of the cylinder and which is fixed to the front end of the drive member,

  is housed with the possibility of sliding in the cylinder.

  The other end of the rod is attached to a piston 76 dis

  placed inside the cylinder and located next to a dia-

  flexible diaphragm 77 which divides the cylinder into a front chamber and a rear chamber. When compressed air is admitted into the front chamber, the piston 76, the rod 75

  and the drive member 52 are driven backward.

  When the air is exhausted from the front chamber, a spring

  helical 78 retracts the piston, the rod and the

dragging forward.

  When the arms 14 are to be retracted, the shift lever 37 is usually tilted counterclockwise in the position shown in FIG. 2 so as to place the gearbox 21 in its speed position. high. Similarly, the handle 62 is tilted counterclockwise in the position shown in Figure 3, so as to place the pawl 51 in its active position and the pawl 50 in its inactive position. Compressed air is then alternately sent to and evacuated from the front chamber of the cylinder 74 so as to drive the drive member 52 forward and retract to

  the front of this drive member. When the body of

  Thirdly, the ratchet teeth 51 mesh with the teeth of the ratchet wheel 47 so as to rotate the ratchet wheel 47 and the toothed wheel 46 in a clockwise direction (FIG. 4). The toothed wheel 46 rotates the toothed wheel 44 and the crank shaft 22 counterclockwise so as to cause the arms 14 to be withdrawn at a relatively fast speed. When the drive member 52 advances, the. inactive ratchet 50 simply moves empty in front of the ratchet wheel 45 so as to leave the toothed wheel 44 free to be driven by the toothed wheel 46. When the drive member is retracted, the ratchet 51 disengages from the ratchet wheel 45. geared drive position with ratchet wheel 47

  and therefore the two gears remain momentarily

  rest until the driving member is again advanced so as to cause the ratchet wheel 47 and gear wheel 46 to be driven by the

ratchet 51.

  To deploy the arms 14, the handle 62 is rotated clockwise in the position shown in Figure 5 so as to place the pawl 51 in its inactive position and the pawl 50 in its active position. In most cases, the lever 37 is usually left in the high speed position when the arms are initially deployed in such a way that this deployment can take place at a high speed.

fast speed.

  When compressed air is admitted into the cy-

  lindre 74 to advance the drive member 52, the pawl 50 contacts and drives the ratchet wheel 45 so as to rotate the toothed wheel 44 in the direction of clockwise (see Figure 6). As a result, the crankshaft 22 is rotated clockwise so as to deploy the arms 14. The idle ratchet 51 moves empty in front of the ratchet wheel 47 during the advance stroke. of the drive member 52, and the gear wheel 46 simply turns empty. When the drive member is retracted, the pawl 50 disengages from its drive meshing with the ratchet wheel 45 so that the two gears

are momentarily stopped.

  Once the feet 12 contact the ground, the lever 37 can be turned anti-clockwise so as to adjust the gearbox 21 to its low speed high torque position. Therefore, with the continued actuation of the drive member 52, the high torque required to lift

  the trailer 11 is applied to the transverse shaft 17.

  If there is no available air supply

  to actuate the cylinder 74, it is possible to actuate

  the operation device 10. This operation is carried out by placing the inverting handle 62 in the positb.on dézirée, by installing an adapter (not shown) on the crank, in the hub 48 and in

  turning the hand crank in the proper direction.

  From the foregoing, it will be apparent that the present invention provides the art with a new and improved device for operating a train of supports, which can be installed on the trailer without requiring the removal of the one of the arms 14 and sleeves for access to the transverse shaft 17. Since the actuating device acts via the crank shaft 22 and the gearbox 21, the device Actuation 10 does not need to be equipped with a two-speed transmission system. The reciprocating movement of the drive member 52 is converted into a rotational movement for driving the transverse shaft 17 by means of the gears 44 and 46, the ratchet wheels 45 and 47 and the ratchets 50 and 51 which are arranged compactly inside the housing 30. By simply pivoting the lever 60, it is possible to actuate one of the pawls, the other pawl can remain unactivated so as to allow the reversal of the direction of rotation. Therefore, the actuating device is

  easy to install and can be of relatively compact, lightweight and economical construction.

  According to another aspect of the invention, the actuating device 10 is equipped with a cyclic operating valve 80 (FIG. 9) which is extremely reliable and efficient, making it possible to automatically alternate intake and exhaust of the compressed air in and out

  of the cylinder 74. In addition, the cyclic operating valve

  that is controlled by an on-off valve 81 extreme-

  reliable, which is characterized in particular by its

  ability to automatically disconnect the action device

  after the arms 14 have been brought in;

  in their fully retracted position.

  As shown in Figure 9, the valve

  cyclic operation 80 includes a body 82 which is

  on the lower side of the housing 30, inside the latter, a drawer 85 is mounted in a bore 83 formed

  in the body, so as to be able to slide into this.

  Sure that the seal is provided by an O-ring 84. The slide 85 has a forwardly projecting rod 86 of reduced diameter, mounted with a radial clearance in a passage 87 which constitutes an extension.

  drilling. An intake passage 88 for the supply air

  (for example air at a pressure of about 700 k Pa is formed in the body 82 and opens into the passage 87, while an outlet passage 90 leads to the outside of the body and communicates with the chamber before the cylinder 74 via a pipe 91. A

  outlet passage 92 is also provided in one end.

  mity of the body 82 and opens into the atmosphere. The passages 87, 90 and 92 are all able to communicate with a room

  93 located near the front end of the body.

  An elastomeric valve element 94, having a rear face 95 and a front face 96 whose diameters are greater than the diameters of the passages 87 and 92, respectively, is

  disposed within the chamber 93 and is attached to the rod 86.

  When the valve member 94 is moved to the right (Figure 9), the face 96 of the valve closes the outlet passage 92, while the face 95 of the valve opens the passage 87 and establishes a communication between the passage of the valve. 88 admission and the cyclider 74 via the chamber

  93, 90 and 91. A shift in

  Valve 94 to the left has the effect that the

  the valve closes the passage 87 so as to cut off the

  the intake air towards the cylinder 74 and simultaneously the face 96 of the valve opens the passage 92 so that the air in the cylinder can escape into the atmosphere via of the

  conduit 91, passage 90, chamber 93 and passage 92.

  A rod 98 (FIGS. 3 and 9), the rear end of which is slidably supported by a plate 99 curved upwards from the bottom wall of the casing 30, is read from the drawer 85 and extends at the back of the latter. An L-shaped member or a stirrup 100 (FIGS. 7 and 9) having a cross-section

  inverted U shape is rigidly attached to the underside

  upper part of the drive member 52, the lower end of the yoke 100 being bent astride the. rod as shown in Figure 7. The lower end of the yoke is - clamped between two washers 101 and 101 (Figure 9), which are fitted with possibility of sliding on the rod 98. A coil spring 103 is fitted on the rod and is located between the washer 102 and a third washer 104 which is fitted so as to slide on the rod and which abuts against the rear end of the slide 85. Another coil spring

  is pushed over the stem in the vicinity of the

  101 and can enter a housing 106 formed in a block 107 which is fixed rigidly to the end

back of the stem.

  It is assumed that the piston 76 of the action device

  73 is fully retracted, as shown in FIG. 9, and the inlet compressed air is supplied to the cyclic operating valve 80 through the passage 88. When the piston is fully retracted, the The drive 52 is in a retracted position, which causes the stirrup 100 to act through the washer 102, the spring 103 and the washer 104 to hold the slide 85 in an open position shown on FIG. 9. With the tifoir then in this position, the face 96 of the valve closes the outlet passage 92 while the face 95 of the valve opens the passage 87. Consequently, compressed air is sent to the chamber before the cylinder 74 through the passages 88 and 87, the chamber 93, the passage 90 and the pipe 91. The piston 76 is therefore offset

  towards the back so as to advance the body of

flow 52.

  When the drive member 52 advances, the stirrup 100 and the washer 101 slide back along the rod 98 and move away from the spring 103 and consequently the mechanical force to maintain the

  drawer 85 in its open position is removed. How-

  In this case, the drawer remains in this position due to the action of the compressed air present in the chamber 93 acting against the face 95 of the valve and exerting a force directed to the right on the slide. Therefore, the piston 76 and the drive member 52 continue to

move backwards.

  When the drive member 52 approaches the end of its advance stroke, the spring 105 enters the housing 106 located in the block 107 and contacts the bottom of the housing before the washer 101 contacts the block. As the drive member continues to advance, the spring 105 is compressed between the washer 101 and the bottom of the housing 106. The washer 101 then contacts the block 107 and consequently the latter is pushed back towards

  the rear and acts through the rod 98 of

  It is also possible to move the spool 85 to the left against the force exerted on the valve face 95 by the pressure in the chamber 93. Therefore, the face 95 of the valve moves toward the passage 87 of the valve. so as to close the flow of the intake air towards the cylinder 74 and, simultaneously, the face 96 of the valve departs from the outlet passage 92 by opening the latter. By

  therefore, the air is discharged out of the cylinder through

  pipe 91, passage 90, chamber 93 and passage 92 to stop any continuation

  the displacement of the drive member 52 to the rear.

  When the face 96 of the valve first opens the outlet passage 92, the compressed spring 105 acts between the washer

  101 and block 107 so as to shift rapidly the

  85 to the left on its full stroke and thus to ensure a total opening of the outlet passage 92 and a total closure of the intake passage 87. The spring 78 therefore begins to retract the piston 76 and the organ

  52 in a forward direction.

  At the beginning of the withdrawal of the training

  52, the yoke 100 begins to slide forward along the rod 98. The washer 101 and the spring 105 follow this movement back of the caliper because as shown in Figure 1, the housing 30

  and the cyclic operating valve 80 arranged in the

  the inner casing are inclined downwards and forwards and therefore the gravity is exerted by causing a displacement of the washer 101 and the spring 105 forward along the rod 98. When the caliper 100 away from the block 107, the mechanical force for maintaining the slide 85 in its closed position is no longer exerted on the rod 98. However, the drawer is held in its closed position by the pressure of the air in the passage 87. This pressure acts against the surface of a piston 108, formed at the junction of the slide 85 and the rod 86.

  piston surface 108 is greater than the effective surface area

  the face 95 of the valve when this face is applied

  In this way, the force developed by the pressure acting on the piston 108 to push the slide 85 to the left is greater than the opposing force developed by the pressure acting on the face 95 of the piston. valve and therefore, the drawer remains closed when the drive member 52 retracts. When the drive member 52 approaches the end of its withdrawal stroke, the stirrup 100 pushes the washer 102 against the spring 103 which, in turn, presses the washer 104, so as to avoid the forced application of a load in the form of a sudden shock. After being compressed, the spring 103 tends to act in the manner of a

  rigid connection and therefore the mechanical force

  The slide 85, through the spring, overcomes the pressure acting against the piston 108 so that the slide moves rapidly to the right in its open position (FIG. 9) so as to open the passage 87 and close the passage 92. and thereby trigger another cycle. When the passage 87 is open the effective surface of the face 95 of the valve is greater than the surface of the piston 108 and therefore the pressure in the chamber 93 tends to push the slide 85 to the right

in its open position.

* Therefore, the cyclic operating valve

  that 80 automatically admits compressed air into the cylinder 74 and discharges compressed air therefrom in a manner synchronized with the displacement of the drive member 52 due to the action of the actuated valve by the drive member when the latter reaches

  the end of each race. The race of the organ of

  trailing is definitely more important than running

  valve 85, but the air acting on the

  faces 95 and 108 is used to keep the cyclic operating valve 80 open or closed during

  the movement of the drive member between the ends

  mended of his race. As a result of the action of the springs 103 and 105, the displacement of the valve is ensured and no load in the form of a sudden shock is imposed on the valve 80 or the casing 30 when the drive member 52

  stops and changes direction of movement. The function valve

  cyclic basis melting so extremely reliable and without irregularity, and with a lifetime

useful important.

  As mentioned previously, the on-off valve 81 controls the admission of compressed air

  in the cyclic operating valve 80 and, in accordance with

  In accordance with the present invention, the actuator 73 is automatically disconnected once the arms 14 are fully retracted. As shown in FIG. 9, the start-stop valve 81 has a body 110 which is mounted below the bottom wall of the housing at a right angle to the body 82 of the cyclic operating valve 80. outlet passage 111 is formed in the body 110 and communicates with the inlet passage 88 of the cyclic operating valve 80 so as to send compressed air to this valve, the passage 111 also communicating with a chamber 112 located in the body 110. Similarly is formed in the body 110 an intake passage 113 which communicates with the chamber 112 by means of an axial passage 114 located in the body. The intake passage 113 is connected to a conduit 115 which, in turn, is connected to a source

  compressed air (for example the same source as that used

  to pressurize the brake system of the trailer 11).

  A drawer 116 (FIG. 9) is mounted with possibility

  sliding tee inside a bore 117 formed in the body 110 and its sealing is obtained by means of an O-ring 118. On one end of the slide 116 is formed a rod of reduced diameter 119, which is accommodated with a certain radial clearance in the passage 114. The rod carries a valve element 120 having faces 121 and 122, the face 121 of the valve being able to close the passage

  114 so as to seal the passageway

  112 of the chamber 112 and the passage 111. The face 122 of the valve can be applied against the end of a housing 123 and close passages 124 formed in the housing and communicating with a chamber 125 located inside this housing. last and which is vented through an outlet passage 126 through the housing. The housing 123

  is attached to the inner end of the body 110 of the valve.

  A button 130 (FIG. 9) that can be pushed back

  internally so as to open the valve 81 and be pushed back

  externally in order to close this valve, is

  attached to the outer end of the slide 116. A flexible cover

  131 is mounted between the body 110 of the valve and the

  outer trough of the drawer 116 so as to prevent

  dust and the like to enter the bore 117.

  When the button 130 is pressed internally by hand, the member 120 of the valve is moved to the left (FIG. 9) so that the face 121 of the valve opens the passage 114 and the face 122 of the valve closes. passage 124. As a result, the intake air from line 115 is fed to cyclic operating valve 80 through passages 113 and 114, chamber 112, and passageway 111 so as to operating the actuating device 73. Since the passages 124 are closed by the face 122 of the valve, the intake air can not escape through the

exit passage 126.

  When the actuating member is to be unplugged, the button 130 (i.e. to the right in FIG. 9) is externally pulled out so as to move the valve member 120 and to cause the opening of the passages 124 through the face 122 of the valve and simultaneously closing the passage 119 by the face 121 of the valve. Since the passage 114 is closed, the intake air inlet to the cyclic operating valve 80 is cut off. Although the intake air pressure in the passage 114 acts against the face 121 of the valve and tends to move the element

  valve 120 to the left, this same pressure also acts

  against a bearing 135 located at the junction of the slide 116 and the rod 119. The effective surface of the bearing 135 is greater than the effective surface of the face 121 of the valve when the latter is closed and therefore the intake air keeps the valve 81 closed. related

  open passages 124 ventilate chamber 112 through

  mediate the outlet passage 126 and therefore the chamber is released from any pressure tending to open the valve. To achieve the automatic closure of the valve 81 when the arms 14 are fully retracted, a piston 136 (Figure 9) is disposed within the chamber 125 and its outer end can momentarily contact the face 122 of the valve and move the valve. valve member 120 outwards (or to the right in FIG. 9) so as to close the valve 81. On the inner end of the piston 136 there is provided a head 137 which normally applies, closing it against a passage 138 located in the inner end of the housing 123. The surface of the head 137 is significantly larger than the surface

  of the passage 138. A coil spring 139 is engaged

  above the piston 136 and is compressed between the housing 123 and the head 137 so as to push the latter to the left in a closed position relative to the passage 138. The passage 138 communicates with the front chamber of the cylinder 74 via a pipe 140 that

  extends between the housing 123 and the cylinder.

  When the arms 14 must be retracted upwards, the driver of the truck must simply push the button 130 to move the valve member 120 so that the face 121 of the valve opens the passage 114 and the face 122 of the valve contact the end of the housing 123 (see Figure 9). When the compressed air enters the cylinder 74 in order to retract the arms 14, the pressure in the passage 114 keeps the valve member 120 in the position shown in FIG. 9 since the pressure acts against the surface

  relatively large face 121 of the open valve.

  Therefore, the driver does not need to continue pressing the button 130 to hold the valve 81 open

  and therefore can leave the side of the trailer 11.

  Once the arms 14 have been fully retracted, the pressure rises in the cylinder 74 to a value (for example 245k2a) greater than that (14QkP.a) required to advance the actuating member 52. while the arms knows during retraction. The increased pressure inside cylinder 74 is transmitted to passage 138 via line 140 and. acts against the head 137 so

  to move the piston 136 outward or to the right.

  As soon as the head opens the passage 138, the pressure existing in the latter acts against the total surface of the head so as to push back abruptly and quickly

  the piston 136 to the right. The extré-

  The right side of the piston contacts the valve face 122 and pushes the valve member 120 to the right so as to close the valve 81 to shut off the flow of compressed air to the cylinder 74 and disconnect it from the valve.

  automatically makes the actuating device 73.

  that the pressure prevailing in the cylinder 74 and in the pipe 140 is annihilated, the spring 139 pushes the piston 136 in the position shown in Figure 9 so as to close the passage 140. It should be noted that there is no seal between the head 137 and the chamber 125 and that consequently air in the chamber can freely escape into the atmosphere through

  through the ventilation passage 126 when the res-

  Fate 139 pushes the piston 136. That is why there is no risk that air is trapped between the head 137 and the inner or left end of the housing 123, which

  could cause irregular operation of the piston 136.

  When the arms 14 are withdrawn, the pressure of the air developed in the cylinder 74 is not sufficient to

  overcome the force of spring 139 and therefore the

  remain in the position shown in the figure

  9 until the arms reach their full position.

  retracted and cause the establishment of pressure

  in the cylinder. When the arms are deployed, the pressure

  in the cylinder is established when the feet 12

  contact the ground and begin to lift the trailer 11.

  Therefore, the driver must manually hold the button 130 depressed so as to prevent the piston 136 from closing the valve 81 until the trailer has been raised to the desired height. However, as explained above, it is not necessary for the driver to take care of the valve 81 once the withdrawal

arms started.

Claims (12)

  An actuating device for the support train of a semitrailer having two extendible and retractable arms (14) spaced laterally and between which extends a transverse shaft (17) projecting laterally outwardly. of one of the arms (14), said transverse shaft (17) being operable to extend or retract the arms (14) according to its direction of rotation, characterized in that the actuating device (10) comprises a housing (30), means (31) for mounting the housing (30) in a position close to one of the arms. (14), a rotatable member (40) carried by the housing, means (21) for operably connecting the rotatable member (40) to the transverse shaft (17) at a location laterally outwardly said arm (14), and mechanically actuated means (33, 42, 74, 80) carried by said housing (30) to selectively rotate said member (40) in a clockwise direction a   shows, either in the opposite direction of the clockwise.   2. Actuating device according to the claim   1, characterized in that the connecting means comprise a gear mechanism (21) having a crank shaft (22) connected to the rotatable member (40) and having an output member meshing with the shaft.   crank (22) and connected to the transverse shaft.   3. Actuating device according to the claim   2, characterized in that the rotary member (40) has a tubular hub dimensioned to be fitted on one end of the crank shaft (22) and in that said connecting means (33, 42) connect the hub has said end of the crankshaft (22), so that it can rotate with it while being able to slide axially through relation to the tree.   4. Actuating device according to the claim   1, characterized in that it further comprises a first   first and second rotary gear wheels (44, 46)   reciprocally, one of which (44) can be connected to the rotary member (40) to rotate the rotary member, a first and a second unidirectional ratchet wheel (45, 47) rotatable with said first and second second gears (44, 46) and having teeth rotated in the same direction, first and second ratchets (50, 51) associated with the first and   second ratchet wheels (45, 47), mechanically actuated means   comprising a drive member 152), means (62) for reciprocatingly driving said drive member (52) on feed and return strokes, said first and second pawls (50, 51) being mounted on the drive member (52) to reciprocate the drive member (52) and to move relative to   the drive member (52) between active positions.   and inactive relative to aax said first and second wheels   ratchet (45, 47) and each of said pawls (50, 51) for   to be rotated in such a way as to   ratchet wheel (45, 47) associated with it, but only   when the pawl is in its active position and the drive member (52) is moved over its advance path, and means (60) selectively operable and movable between a first position causing the passage first and second pawls (50, 51) in their active and inactive positions, and a second position causing the passage of the first and second   ratchets in their inactive and active positions respectively tively.   5. Actuating device according to the claim   4, characterized in that the pawls (50, 51) are mounted on said drive member (52) so as to pivot between said active and Cixotile positions, in that. that resiliently bendable means (54) act between the drive member (52) and each pawl 50, 51) and push the pawl into its operative position, in that said means (60) can be actuated in such a manner that selectively comprise a lever mounted to oscillate between first and second positions and have arms (63, 64) for pivoting one of said pawls (50, 51) into its inactive position and releasing the other pawl so that it pivots into its active position when the lever (60) pivots in one of its positions, said arms pivoting the other pawl into its inactive position and releasing the first pawl so that it comes by pivoting into its active position when the lever pivots. in the other of his positions.   6. Actuating device according to the claim   5, characterized in that it further comprises a locking device (61, 70) for maintaining, with the possibility of releasing, said lever (60) in each of his positions.   7. Actuating device according to the claim   6, characterized in that the locking device (61, 70) comprises two leaf springs (70) enclosing one of the arms (63, 64) and frictionally contacting the arm.   8. Actuating device according to the claim   4, characterized in that the first and second gears (44, 46) are made in one piece with   said first and second ratchet wheels (45, 47).   9. Actuating device according to the claim   1, characterized in that the mechanically actuated means   (33, 42, 74, 75, 80) comprise a cylinder (74), a rod (75) slidably mounted in the cylinder and movable in a first direction when a pressurized fluid is admitted into the cylinder. one end of the cylinder (74), means operable to move the rod (75) in the opposite direction when the pressurized fluid is discharged from said end of the cylinder (74), means (52) mounted between said rod (75); 75) and the rotatable member (40) to selectively rotate said member clockwise or counter-clockwise when the rod (75) is moved in at least one direction. one of said directions, a cyclic operating valve (80) adapted to be selectively energized by a fluid under pressure and having a slide (85) movable on a predetermined stroke between a first position of admission of the fluid under pressure into said ext cylinder end (74) and a second evacuation position   fluid under pressure outside said end of the cylinder   dre, a member (76) connected to the rod (75) and movable therewith on a stroke which is greater than the travel of the slide (85) of the valve (80), said member (76) being able to act when gets closer to one or the other   ends of its stroke, so as to modify the posi-   the valve (85) of the valve, and means (95, 108) thereon and responsive to the fluid under pressure for holding the valve spool in the first position when said member (76) moves between the ends   its course in the said first direction and for maintaining   position the valve drawer (85) in the second position   said member (76) moves between the ends   of his race in the opposite direction.   10. Actuating device according to the claim   9, characterized in that said last-mentioned means comprise first and second opposing faces (95, 108) on the valve spool (85) and subjected to the fluid under pressure, in that the first ( 95) has a free surface greater than the free surface of the second face (108) when the valve spool is in one of its positions and having a free surface smaller than the free surface of the second surface   when the valve spool is in its other position.   11. Actuating device according to the claim   9, characterized in that it further comprises a manually operable and selectively movable control valve (81) between an open position, in which the pressurized fluid is supplied to the cyclic operating valve (80). , and a closed position cutting off the supply of the compressed fluid to said cyclic operating valve (80), and means responsive to the pressure in one end of the cylinder (74) for automatically moving the control valve (81) therein bringing into the closed position after said valve   control (81) was manually placed in its position.   open and in the case of an increase to a predetermined value of the prevsion prevailing in said end of the cylinder (74).   12. Actuating device according to the claim   1, characterized in that the mechanically controlled means   (33, 42, 74, 75, 80) comprise a cylinder (74), a   rod (75) mounted so as to slide in the cylinder   and being movable in a first direction when the compressed fluid is admitted into one end of the cylinder (74), means operable to move the rod (75) in the opposite direction as the compressed fluid is discharged from the end of the cylinder (74), means (52) mounted between the rod (75) and said rotatable member (40) for selectively rotating said member in a clockwise or counter-clockwise direction when the rod (75) is moved in   at least one of said directions, an operating valve   cyclic element (80) adapted to be selectively energized by a compressed fluid, said cyclic operating valve (80) being displaced between a first position, wherein the pressurized fluid is admitted to said end of the cylinder (74), and a second position in which the pressurized fluid is discharged out of said end of the cylinder (74), means connected to the rod (75) operable to move   following a back-and-forth movement the operating valve   cyclically (80) between said positions, when the rod (75) is moved back and forth,   a control valve (81) operable manually   selectively movable between an open position, delivering fluid under pressure to the valve   cyclic operation (80) and a closed position   feeding the pressurized fluid to the cyclic operating valve (80) and means responsive to the pressure in said cylinder end (75) to automatically move the control valve (81) to its closed position after this valve The control device has been manually moved into the open position, and in the case of a pressure change in said extrarity of the cylinder (75) setting the pressure to a predetermined value.