MXPA01001690A - Fifth wheel lock release - Google Patents

Abstract

The object of the present invention is to provide a fifth wheel hitch release mechanism enabling a release handle to be effectively pulled with a small force. This fifth wheel hitch comprises a bifurcated hitch plate 16 defining both a tapered kingpin receiving opening 5 and a throat section 18, a pair of kingpin-receiving pivotal jaws 4 located at the throat section 18, a jaw fixing yoke 44 movable between a jaw fixing position and a jaw release position, a cam follower 62 provided at the yoke 44, a cam 70 having cam raceways 70a and 70b and attached to the hitch plate 16, a cam-actuating pull rod 78 for pivoting the cam 70 to displace the yoke 44 to the jaw release position, and a cam engagement pin 64 attached to the yoke 44 to inhibit the yoke 44 from moving too early to the release position.

Description

FIFTH WHEEL CLOSING RELEASE BACKGROUND OF THE INVENTION This invention relates to a coupling for the fifth wheel and in particular to a latching release actuating mechanism.

Fifth wheel hoists employing a straddle jaw fork for gripping the jaws of engagement around a master pin are described in US Pat. Nos. 4,428,595 4,106,793; 3,013,815; 3,485,513; 3,640,549; and 2,982,566.

This type of coupling has been found to be reliable in operation. One difficulty experienced, however, is the amount of manual pulling force required to release the latch. Most people have very little or no difficulty, but if the driver is small or a less robust constitution, the pull of the liberator can be annoying. As will be apparent from the aforementioned patents, the cam plate for the latching release mechanism is typically formed to have an internal cam track having secondary and primary pockets or notches for engagement by a cam follower of the roller type. These are described in Patent No. 3,013,815 as the forward-facing bolster 47 and the rearward-facing bag 48. The forward-facing bag 47 engages the cam follower 4 when the fork 33 is in the open position of the meshing jaws. of the master bolt 24, while the rearwardly directed pocket 48 engages the cam follower 42 when the shoe 33 is in the closed position of the jaws.

Synthesis of the invention The present fifth wheel hitch structure provides a fifth wheel release mechanism that allows the operator to efficiently pull the release handle with considerably less effort than previously required, even up to 40% reduction in effort. to pull the handle. The cam mechanism is specially designed to allow a novel cam top bolt in the fork to engage an externally configured surface of the cam, in addition to the usual cam follower in the inner cam surface to thereby allow a novel geometry of internal cam surface which allows a better leverage to manually pull the release handle.

The novel latch release mechanism has the cam stop bolt added to the separate fork of the conventional cam follower in the fork, and cooperates with the outer surface of the cam plate to inhibit the pitchfork from moving prematurely to its position. Thus, the inner cam track of the plate can be reconfigured to increase the cam leverage on the cam follower which retracts the fork to thereby release the engaging jaws.

These and other features, advantages and objects of the present invention may be better understood appreciated by those with skill in the art by reference to the following descriptions, appended drawings claims.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is a top view of a fifth wheel hitch constructed in accordance with the present invention; Figure 2 is a partial cross-sectional view of the fifth wheel hitch taken along the lines 2-2 'in Figure 1.

Figures 3 to 8 show the lower side of the novel fifth wheel hook arrangement, which shows the sequential stages of the hook mechanism in cooperation with a conventional master pin. For purposes of clarity, Figures 3P to 8P describe the engagement mechanism of the prior art in corresponding sequential stages during cooperation with the conventional master pin, to clearly demonstrate the differences of the novel construction. Figures 9 and 10 illustrate the different conditions that may occur during the operation of the novel arrangement of the fifth wheel hitch. Figures 9P and 10P illustrate the different conditions that may occur during the operation of the fifth wheel hitch arrangement. In figures 3 to 10 and 3P to 10P: Figure 3 is the bottom view of the novel fifth wheel coupling assembly showing the fork in a nominal position with both the cam hook pin added and an auxiliary lock catching the fork; Figure 3P is the bottom view of the fifth wheel coupling assembly showing the fork in a nominal position with both the additional cam hook pin and an auxiliary lock catching the fork; Figure 4 is the bottom view of the novel fifth wheel coupler assembly with the release handle at approximately 50% of its trajectory when pulled, and the auxiliary lock released; Figure 4P is the bottom view of the hook assembly for the fifth wheel with the release handle at about 50% of its trajectory when pulled, and the auxiliary lock released; Figure 5 is the bottom view of the novel fifth wheel latch assembly with the fork releasing the lock jaws near the maximum effort point manually pulled on the release rod; Figure 5P is the bottom view of the conventional fifth wheel hitch assembly, with the fork releasing the locking jaws near the maximum point of manual pull effort on the release rod; Figure 6 is the bottom view of the novel fifth wheel coupler assembly with the engagement jaws in an open position so that the master pin can exit the lock; Figure 6P is the bottom view of the conventional fifth wheel hitch assembly with the hitch jaws in an open position so that the master bolt can exit the lock; Figure 7 is the bottom view of the novel fifth wheel hitch assembly wherein the master bolt h emerges from the lock, forcing the horquet tips into the lock jaw recesses, and the cam is free to move to the position of "ready to be coupled"; Figure 7P is the bottom view of the conventional fifth wheel hitch assembly wherein the master bolt has come out of the lock, forcing the horquet tips into the lock jaw recesses, and the cam is free to move to the position of "ready to be coupled"; Figure 8 is a bottom view of the novel fifth wheel hitch assembly, with the cam in the "ready to engage" position d for a master bolt entering the hitch to strike the back of the lock, forcing the closing jaws to be closed, whereby the compression spring of the fork moves the fork down to a closed position and the force release handle spring rotates to a closed position as in Figure 3; Figure 8P is a bottom view of the conventional fifth wheel hitch assembly with the cam in a "ready to couple" position for a master bolt entering the hitch to strike the back of the lock, forcing the jaws of closure to be closed, whereby the compression spring of the fork moves the fork down to a closed position and the release handle spring forces the cam to rotate to a closed position as in Figure 3P; Figure 9 is a bottom view of the novel fifth wheel coupling assembly showing the closed position d of the master pin so that if the fork is inadvertently forced forward after coupling, it is completely secured through the mechanism; Figure 9P is a bottom view of the conventional fifth wheel hitch assembly showing the position d closing the master bolt in such a way that the fork and inadvertently forced forward after coupling, this is completely secured through the mechanism; Figure 10 is a fragmentary bottom view of the novel fifth wheel hitch assembly showing the fork in full adjustment, near the end of the design life of the hitch jaw; Y Figure 10P weights a fragmentary bottom view of the fifth wheel hitch assembly showing the fork in full adjustment, near the end of the design life of the hitch jaw.

Detailed description of the preferred embodiment In the description that follows, the terms forward and backward refer to the front and rear parts of the hitch when it is mounted in a conventional tractor. The details of the trailer of a trailer and of a conventionally-hung master bolt, and of the normal fifth-wheel hitch mounting components are described in order to maximize the clarity of the hitch characteristics which are unique to this invention.

The fifth wheel assembly 1 basically comprises a hitch 2 which has a conventional fifth wheel hitch plate 16 with a bifurcated rear part straddling a hitch throat 18 and a mouth 5 in a conventional manner as shown in detail in Figure 1. The hitch 2 comprises a master bolt lock mechanism having a pair of pivoted locking jaws 4 which form the plug mouth 5 in which a conventional master bolt, such as the one described in patent No. 4,428,595, it is retained. The fifth wheel hitch will be fastened to a tractor frame in a conventional manner using a pair of stubs 15 which pivotally connect the fifth wheel plate to the frame of the tractor, as in patent No. 3,640,549, so that the Fifth wheel plate can tilt down and back. The bifurcated structure includes a pair of ramps projecting backwardly at a slope 17, which straddle and define a tapered rear-facing master bolt receiving throat 18 and a blind mouth 5 around which the quijad 4 closes or closes. open to retain or release the master bolt As illustrated in Figure 3, the locking jaws 4 are positioned as shown on the left-hand right sides of the mouth, these have a substantially identical construction but a mirror image. The jaws are adapted to match the smaller diameter part, for example, e neck of a master bolt. These jaws are pivotably mounted on the fifth wheel assembly on vertical pivot pins 41 which extend through the jaw opening 25 and have their upper ends mounted on the fifth wheel coupling plate 16. This hook plate it has ribs that project downwards astride the space controlled by both jaws. These ribs have conventional openings formed therein so that, in the unlocked engagement position, the jaws 4 can pivot outwardly through these apertures (Figures 7 and 8).

A conventional U-shaped shroud 44 is straddled between the tapered inward and backward ribs. The shingle 44 includes a transverse leg 44a and a pair of generally parallel legs 454b extending from the ends of the transverse leg 44a and having wedge-shaped ends 44c for engaging the contact surfaces 3 on the jaw ears 30 projecting outwards, thus retaining the jaws in a closed position. The front surfaces of the jaw ears 30 are concave in a conventional manner to act on the wedge-shaped ends 44c, as explained below. A conventional adjustment device can be connected to the fork 44 to move it back and forth to adjust the closed position of the jaws and secure the closed coupling contact with a master pin. The fork 44 has a fork shaft 44d projecting forward from the center of the transverse leg 44a of the fork 44, and through a front rib 21 of the fifth wheel plate 16. The fork 44 is pressed towards its position from closed to closed by a spiral spring d of compression 54 provided about the axis 44d and captured between the front rib 21 of the plate for the fifth wheel 16 and the transverse leg 44a of the U-shaped fork 44.

As shown in Figure 2, an L-shaped bracket 45 is mounted on the transverse leg 44a of the shroud 44 to thereby provide a mounted bolt portion 45a extending parallel to, and below, the axis of the shod 44d and of the compression spring 54. Projecting through and down from the mounting part of the bolt 45a is a vertical bolt 6 which is preferably a cam follower roller 62 Also projecting downward, separate from the bolt 60, is a second bolt. of vertical cam stop 64. As shown in FIG. 3, the cam follower roller 62 makes contact with an internal cam track 70a in a novel cam plate 7 while the second pin 64 cooperates with a surface rail. of the external cam 70b on the cam plate 70. The cam plate 70 is pivotally mounted in the form of a pivot in the fifth-wheel coupling plate 16 by means of a pin 74, thus pivoting thereon and cooperatively engaged to the roller. cam guide 62 and second pin 64.

As illustrated in Figure 3, the cam plate 7 can be forcedly rotated through a pull rod 78 and its pull-type release handle 78a. The release pull rod 78 has a pivotally mounted end 78 'on a cam plate 70 at a distance spaced apart from the axis of rotation of the lev plate 70 on the pin 74, and has its opposite end which is extends through the fifth wheel plate 16 on a side side thereof and ending at the handle 78a. The pull rod 78 is pressed into a closing position by means of a compression coil spring 80 having one end trapped at one location along the pull rod and the other end trapped against an inner rib near the outer edge of the fifth wheel plate 16.

Referring again to Figure 2, the bolts 60 64 extend through openings in an oblong washer 47 The washer 47 therefore retains a portion 70c of the cam plate 70 between the bolt mounting portion 45a of the bracket 45 of the bolts 60 and 64, and an upper surface of the oblong washer 47. By retaining a portion of the cam plate 7 in this manner, the cam plate 70 is more likely to rotate in a plane that is parallel to the hook plate 16 and the fork shaft 44d. In the past, the cam plates have had the tendency to be manipulated by various forces acting on them, to rotate in an unparalleled plane, which can result in an increased effort to pull the release handle 78a and so both to open the hitch.

By providing a bracket 45 and a positioning pin 60 (and a bolt 64) in the bracket below the fork shaft 44d, instead of the mounting bolt 60 directly on the fork axis as it was done in the past, the distance between the bolt 60 and the bolt 74 can be reduced without requiring a reduction in the length of the compression spring 54. In fact, the length of the compression spring 54 can be increased to extend all the way to the bracket 45 mounted adjacent to the transverse leg 44a of the shroud 44. This allows the compression spring 54 to either apply a greater pressure force to the shingle 44 or allows a resort to be used that has less force per unit length to be used. decrease the distance between the bolts 74 and 60, or greater leverage can be applied by the lev plate 70 to move the shingle 44 from the closed position when the release handle 78a is pulled. As is evident from a comparison of FIGS. 3 and 3P, not only has the distance between the cam follower 62 and the pin 74 been decreased, but also the distance has increased between pin 74 and end 78 'of the rod 78. This increased leverage significantly reduces the force required by the pull handle 78a and therefore the force to open the closing mechanism. Additional reductions in the pull handle force can be made through changes to the spring 54 allowed by the additional length as described above.

The function of the apparatus is described in a sequential form in the figures drawn, particularly in Figures 3 to 8. Figure 3 shows the latching mechanism in a completely closed condition, in the form of a latch made relatively recently with little or nothing d wear. As shown, the locking jaws 4 extend around a master pin whereby the master pin is retained within the mouth or nozzle 5. The jaws 4 are closed in place by means of the fork 44 whose tapered tip 44c they prevent the jaw ears 30 from moving in the respective openings formed in the ribs 19 as it could move when releasing the master pin. The fork 44 is retained in its closed position by means of a pressing force of the compression spring 54 and by means of an auxiliary lock 33, which is pivotally mounted to the hook plate 16 and is pressed to pivot against the transverse leg. 44a of the fork 44. The cam plate 70e held in the position shown in Figure 3 by the force of the release handle spring 80. When in the illustrated position, the cam plate 70 does not apply any force backwards. or forward significantly in the horquet 44.

Figure 4 illustrates the movement and position of the latching elements when the release handle 78a is in the process of being pulled to release the latch, and has been displaced by approximately 50% of its full trajectory with the cam plate. 70 which is pivoted about the bolt 74 When the pull rod 78 is pulled as shown in figure 4 by compressing the handle spring 80, a bolt followed by cam 31 in the auxiliary lock 33 is deflected laterally by means of the outer surface of the cam plate 70 to pivot the auxiliary lock 33 around its pivoted mounting point 35 in the fifth wheel plate 16 so that the end which is opposite the pivotally mounted end can move out of alignment with the transverse leg 44a Wye 44 and do not prevent the fork from being forced forward. As shown, when the cam plate 70 is rotated by force rotated by means of the traction rod 78, the interior of the cam track 70a of the cam plate 70 moves to contact the cam follower 62 and the pla cam 70 therefore forces the cam follower 62 and thus the fork 44 forward and out of the fixed or closed position. Figure 5 illustrates the placement of the lock elements just before a moment of time when the release rod 78 has reached its full extent.

When the release rod 78 is in its full extension as described in Figure 6, the cam plate 70 particularly the inner cam surface 70a thereof have forced the cam follower 62, and therefore the fork 44 (and to the fork shaft 44d to which the cam follower 62 is clamped) forward against the pressure of the compression spring 54, whereby the fork is retracted from the straddling ears 30 of the legs. jaws Concurrently, cam follower 62 moves to a sample 70a 'formed in the inner cam track 70a. The compression force of the spring 54 pushes the cam follower 62 against the back of the groove 70a so that the compression force of the handle spring 80 is insufficient to move the cam follower 62 laterally from the groove 70 when the 78a handle is released. In this manner, the operad can release the handle 78a and the fork 44 is held in an open retracted position. When the fork 44 is in the open position retracted as shown in Figure 6, the spring (not shown) swivels the jaws 4 slightly open until a portion of the tapered front surface 30a of them makes contact with the tips. the 44c horquet When the pull rod 78 is fully extended, as in Figure 6, the auxiliary lock 33 is out of the way of the transverse leg 44a of the fork 44.

Having released the pull handle 78a, the operator is now free to enter the cab of the truck and pull the truck forward. The forward movement of the cam moves the latch forward in relation to the stationary master bolt. This forward movement of the hitch causes the master bolt to push and open the jaws 4 as described in FIG. 7, under the influence of the retreating master bolt While the jaws are pivoted, the tapered front surface portions 30a of the ears of jaw 30 forces the fork 44 further forward against the force of the compression springs 54. As shown in Fig. 7, this additional forward movement of the fork 44 results in a corresponding forward movement of the cam follower 62 and a second pin 64, which removes the cam follower 62 from the sample 70a 'while leading the second pin 64 in contact with the external cam track 70b. Once the cam follower 62 has moved from the groove 70a 'in the cam track 70a, the cam plate 70 is released from the force of the compression spring and is free to rotate. Consequently, the compression force of the handle spring 80 retracts the pull rod 78 and thus pivots the cam plate 70. The cam plate 70 stops pivoting when the second pin 64 is moved to a second groove 70b 'which is part of the cam track exter 70b of the cam plate 70, as shown in figure 8. this point, the jaws 4 have been opened sufficiently to allow the master bolt to exit the latch lock the trailer is so so decoupled. The forced opening of the jaws 4 by means of the master pin results in the tips of the fork 44c being placed within the concave front surface portion 30b of the jaw ears 3 This relative positioning keeps the fork 44 in a forward position while that keeps the jaws open. After this operation, the hitch is in ready state to be coupled without requiring any additional operator manipulation. Therefore, the figure also represents the position of the lock elements when they are in the position ready to be coupled. The hitch in Figure 8 is therefore ready to receive a master pern.

During a coupling operation, the truck is positioned towards a stationary trailer, and therefore, the stationary master pern penetrates the throat 18 and eventually into the mouth 5 of the hitch. While the master bolt completely penetrates the mouth of the hitch, it pushes against the front end of the inner surfaces of the jaws 4 so that the jaws 4 are pivoted completely closed to the position illustrated in FIG. 3 as a result of the closure of the jaws 4, the compression spring and coil 54 forces the shingle 44 backwards so that the tips of the shingle 44c extend beyond, are straddled and make contact with the ears 30 of the jaws 4 as shown in Figure 3. In this condition, the stop bolt 64 moves out of contact with the groove 70b 'on the cam track 70b thereby allowing the handle spring 80 to rotate the cam plate 70 and retract the d pull rod 78 back to its starting positions as in figure 3, once the cam plate 70 has returned to the starting position, the auxiliary lock 33 no longer prevents pivoting under the force of a spring (not shown) in the closing position. The sequence illustrated in FIGS. 3 a is therefore repeated each time the coupling is decoupled and coupled to the trailer master bolt.

Figure 9 illustrates a potential condition resulting from the excessive force of the drawbar resulting from the master bolt penetrating and sticking in the jaws 4 at excessive speed. When this occurs, the master bolt bounces backwards by pushing the jaws 4 open possibly before the fork 44 has fully extended backwards. The rapid movement of the jaws 4 from an open to a closed position can also cause a rebound effect on the cam plate 70 and the spring 80 such that the cam plate 7 rotates to an open position so that the The outer surface of the cam plate 70 will engage in the pin 31, turn over the auxiliary lock 33 and push it out of its closed position. To prevent the plate 70 from turning so far and disengaging the auxiliary lock 33, a protrusion 70b "is provided in the outer cam rail 70b to trap the second stud 64 and serve as a complementary lock. In this manner, pin 64 and cam plate 70 prevent the fork 44 from moving further forward. Therefore, the second pin 64 allows the notch A (FIGS. 8P and 9P) provided in the inner rail of the prior art cam plate to be removed. As a result of this, the inner cam track 70a can be designed in a manner that reduces the effort to pull the handle.

Figure 10 illustrates another potential condition where the pitchfork 44 is in full adjustment near the end of the life of the latching jaw design, for example, the closure jaws 4 have been worn out enough so that the pitchfork 44 can Fully extend backward mechanism.

The above description is considered the preferred embodiment only. Those with skill in the art, modifications of the invention, as well as those who make or use the invention may occur to them. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not It is intended to limit the scope of the invention, which is defined by the following claims, interpreted according to the principles of the patent law, including the doctrine of equivalents.

Claims (16)

1. A fifth wheel hitch that includes: a bifurcated hook plate that defines a gargant and a mouth that receives a master pin, tapered; a pair of pivoted jaws, which receive master bolts in said throat, which can move between the open and closed positions; a jaw securing shifter that can movers rectilinearly between a quip lock position by straddling said jaws when in the closed position, and in a jaw release position; a cam follower in said fork; a cam pivotably coupled to said engagement plate on a pivot bolt, said cam has a configured internal cam track, and a configured external cam track; said internal cam rail cooperates with said cam follower, whereby with the pivoting of said cam, said cam and the cam follower will be able to change said fork to said jaw release position; a cam actuation rod coupled to said cam, spaced apart from said pivot pin, for pivoting said cam to thereby change said fork to said jaw release position; Y a cam stop bolt, separated from said cam follower and cooperating with said external cam rail to prevent said fork from moving prematurely to said release position.

2. The fifth wheel hitch as claimed in clause 1, characterized in that said outer cam track includes a protrusion that receives said cam stopper bolt and therefore acts as a complementary closure.

3. The fifth wheel hitch as claimed in clause 1, characterized in that said traction rod has to push said traction rod and therefore pushes said cam against said pivoting action that changes said fork to said release position of jaw.

4. The fifth wheel hitch as claimed in clause 3, characterized in that it also includes an additional closing element pivotably coupled to a fifth wheel plate and is pivotably movable between a locking position engageable to said fork, and an open position not engageable with said fork, and said closing element has a cam follower operable by said outer cam track to change said closing element from said closing position to said open position.

5. The fifth wheel hitch as claimed in clause 1, characterized in that it also includes a reinforcing element between said cam follower in fork and said stop bolt.

6. The fifth wheel hitch as claimed in clause 5, characterized in that said reinforcing element is an oblong washer and secured at the lower ends d said cam follower and said stop bolt to retain a part of said cam between said washer and said fork.

7. The fifth wheel hitch as claimed in clause 1, characterized in that the fork includes a bracket to which they are secured, said stop bolt and said cam follower.

8. The fifth wheel hitch as claimed in clause 1, characterized in that said stop bolt d is positioned rearwardly of said cam follower.

9. A fifth wheel hitch that includes: a latch plate defining a mouth for receiving a master bolt; a pair of pivoting jaws movable between a closed position and an open position in which a master pin can be received or released; a jaw belayer that moves rectilinearly between a jaw release position and a jaw assurance position by straddling said jaws when in its closed position, said shoe includes a transverse leg, a pair of fork legs that extend backward from the opposite ends of said transverse foot, and a transverse foot axis; a compression spring extending around said shingle axis between a front part of said hook plate and said transverse leg of said fork to push said fork back towards the jaw assurance position; a bracket coupled to said fork and having a bolt mounting part extending in a plane downwardly of said fork shaft and said compression spring; a cam follower extending downwardly from said bolt mounting part of said bracket; a cam pivotally coupled to said latch plate on a pivot bolt, said cam has an internally configured cam rail which cooperates with said cam follower, whereby with the pivoting of said cam, said cam and said cam follower changing said fork to said jaw release position; Y a pull rod coupled to said cam, spaced apart from said pivot pin, for pivoting said cam to thereby change said fork to said jaw release position.

10. The fifth wheel hitch as claimed in clause 9, characterized in that said bracket is coupled to and extends forward of said transverse leg of said fork.

11. The fifth wheel hitch as claimed in clause 9, characterized in that said horquest extends directly downwardly of said fork spring axis of the compression spring.

12. The fifth wheel hitch as claimed in clause 9, characterized in that it also includes a cam stop bolt that extends down from said bolt mounting part of said bracket, separated from said cam follower, said bolt The cam stop cooperates with the external cam track of said cam to prevent the fork from moving prematurely to said release position.

13. The coupling for the fifth wheel as claimed in clause 12, characterized in that said cam stop bolt is placed rearwardly of said cam follower

14. The coupling for the fifth wheel as claimed in clause 12, characterized in that said external cam carriage includes a protrusion to receive a cam stop bolt and therefore act as a complementary lock.

15. The coupling for the fifth wheel as claimed in clause 12, characterized in that it also included an oblong washer secured at the lower ends d said cam follower and said cam stop pin to retain a part of said cam between said washer and dich shingle mounting part of said bracket.

16. The fifth wheel hitch as claimed in clause 9, characterized in that said traction rod has a spring that pushes said traction rod and therefore push said cam against said pivoting action that changes that fork to said position d release of jaw.