US3112100A - Truck-trailer transit mixer - Google Patents

Description

Nov. 26, 1963 E. s. PRICHARD TRUCK-TRAILER TRANSIT MIXER 4 Sheets-Sheet 1 Filed May 31, 1962 INVENTOR. 51 44 5. Pele/#720 M ifdam/ flrroewsys.

Nov. 26, 1963 E. s. PRICHARD TRUCK-TRAILER TRANSIT MIXER 4 Sheets-Sheet 2 Filed May 31, 1962 flrrokNE rs Nov. 26, 1963 E. s. PRICHARD 3,112,100

TRUCK-TRAILER TRANSIT MIXER Filed May 31, 1962 4 Sheets-Sheet 3 INVENTOR.

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K/W r i/m! United States Patent 3,112,100 TRUCK-TRAILER TRANSIT MIXER Evan S. Prichard, Newport Beach, Calif, assignor t0 Challenge-Cook Bros., Incorporated, Los Angeles, Calif., a corporation of California Filed May 31, 1962, Ser. No. 199,090 19 Claims. (Cl. 259-161) This invention relates to a transit mixer for mixing aggregate materials in transit from a bulk-loading plant to a job site, and more particularly to the combination of a truck with a wheeled truck body frame extension or semi-trailer (hereinafter, for purposes of convenience, sometimes referred to simply as a trailer), which combines many of the advantages of a truck transit mixer with those of a motor vehicle trailer, so as to obtain greater pay-load capacity without sacrifice of maneuverability, and so as to provide increased wheel length and better axle weight-load distribution.

In addition to providing increased axle-weight-load distribution, whereas transit mixers generally in use have loading and discharge mechanisms permanently mounted adjacent the open loading and discharge end of their mixer drums, the device of the present invention may also provide a means for removing its loading and discharge mechanism from the vicinity of the open end of the drum, so that the aggregate mix in the drum may be more readily inspected and sampled, prior to discharge from the drum; so that the interior of the drum may be more easily and effectively cleaned after cargo discharge; and so that the loading and discharge mechanism itself may be more readily available for cleaning.

Generally speaking, a transit mix truck is more maneuverable than a transit mix truck-trailer combination having the transit mix drum mounted solely on the trailer, and loading and discharge of cargo is normally more readily accomplished with a truck than with a trucktrailer combination. However, due principally to motor vehicle highway restrictions, but also due to problems of proper transit weight distribution, the carrying capacity of the transit mix drum of a truck is restricted, and payload is limited.

It is therefore an object of the present invention to provide a transit mixer having the maneuverability advantages of a transit mixer truck, but also having increased wheel length and improved weight distribution characteristics during transit provided by the unique trailer of the device, so that a drum of larger capacity may be utilized, and consequently, so that a larger pay-load may be carried.

It is another object of the invention to provide a transit mixer in which part of the overall weight is borne by the truck body frame extension or semi-trailer axle and wheels during transit, but in which the trailer is movable out of following position during loading and discharge operation so as not to interfere with effective loading and discharge.

It is still another object of the invention to provide such a transit mixer in which the loading and discharge mechanism is carried by the trailer, so that during transit the weight of such mechanism is borne by the axle and wheels of the trailer, rather than by the truck, but upon cargo loading or discharge, the loading and discharge mechanism is brought into operative position at the open end of the drum by pivotal movement of the trailer upwardly from its extended transit position.

It is yet another object of the invention to provide a truck-trailer combination which has the turning radius characteristics of a truck, rather than those of the usual truck-trailer combination.

With these and other objects in View, the invention consists of the construction, arrangement and combinaice tion of the various parts of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of the device of the present invention in transit position.

FIGURE 2 is a view similar to FIGURE 1, but with the device in loading and discharge position.

FIGURE 3 is an illustrative plan view showing the turning radius characteristics of the device of the present invention.

FIGURE 4 is an enlarged, fragmentary, detailed side elevational view of the rear end of the device in transit position.

FIGURE 5 is a view similar to FIGURE 4, but with the device in loading and discharge position.

FIGURE 6 is a rear elevational view of the device of the present invention in the transit position shown in FIGURE 4.

FIGURE 7 is a view similar to FIGURE 6, but with the device in the loading and discharge position shown in FIGURE 5.

FIGURE 8 is a diagrammatic illustration of the hydraulic load distributing, shock absorbing, and trailer retracting means of the invention.

FIGURE 9 is a bottom plan view of a first alternative form of construction of the ground contacting wheel assembly for the truck body frame extension or semi-trailer of the device of the present invention.

FIGURE 10 is a rear elevational view of the wheel assembly illustrated in FIGURE 9.

FIGURE 11 is a side elevational view of the wheel assembly illustrated in FIGURES 9 and 10.

FIGURE 12 is a view similar to FIGURE 9, but showing a second alternative form of construction of said wheel assembly.

As illustrated in the drawings, a truck, generally designated as 10, has a body frame 11 having a forward end 12 and a rear end 13. Steering wheels 14 are mounted forwardly, adjacent forward end 12, on a steering axle '15; and truck rear wheels 16, which may be standard tandem rear wheels, as illustrated in the drawings, are mounted rearwardly, adjacent rear end 13, on axles 17. An operators cab 18 is mounted forwardly on body frame 11.

A trailer, generally designated as 20, has a frame 22 having a forward end 24 and a rear end 26. Frame 22 of trailer 20 is pivotally mounted at its forward end 24 to body frame 11 of truck '10 adjacent rear end 13 of frame 11. Pivotal mounting of frame 212 to frame 11 may be accomplished by providing a pair of aligned trunnions 27 mounted on opposite sides of frame 11 and extending below frame 11, with a cross-bar 28 rotatably mounted between said trunnions 27 and below said frame 11, forward end 24 of frame 22 being mount ed on and supported by said bar 28.

Trailer frame 22 is comprised of a first pair of substantially parallel arms 30 which, when the device is in the transit position illustrated in FIGURES 1 and 4, are rearwardly extending and upwardly inclined; a second pair of substantially parallel, rearwardly extending, but downwardly inclined arms 32, which are integrally formed with said arms 30 to form an obtuse angle therebetween; a third pair of arms 34, rearwardly extending in converging relationship toward each other and slightly upwardly inclined, which are integrally formed with said arms 32; a fourth pair of substantially parallel arms 36, rearwardly extending and substantially parallel to the ground (designated 37) which are integrally formed with said third pair of arms 34; and a rear cross member 38, which joins said fourth pair of arms 36.

A cross-beam 40 extends transversely between arms 36 adjacent rear cross member 38. A swivel pin 42 is centrally mounted on cross-beam 40 adjacent the upper end 44 of said pin 42, said pin 42 extending vertically downwardly from trailer 20 when trailer 20 is in transit position. At the lower end 46 of pin 42 a transverse axle 48 is mounted at substantially the center of said axle 48. A pair of trailer wheels 50 is mounted on said axle 48 and disposed on opposite sides of said pin 42. If desired, said wheels 50 may be equipped with mud guards 52 and splash guards 54.

Rotatably mounted on frame 11 of truck is a mixer drum 60 which has a forwardly disposed closed end 62 and a rearwardly disposed, upwardly inclined open end 64 adapted to receive and discharge cargo. In the manner which has become standard in the transit mixer industry, drum 60 is rotatably supported on truck frame 11 at its forward closed end 62 by a drive mechanism, generally illustrated in FIGURES 1 and 2 of the drawings and designated 65 (no particular claim being made to the details of the drive mechanism employed). Drum 60 is rearwardly supported on truck frame 11, also in a manner which has become standard in the industry, as by a pair of stanchions 66 which support rollers (not illustrated), which rollers in turn bear on a ring 67 mounted externally on drum 60 adjacent open end 64.

Open end 64 is disposed adjacent the vertical plane of rear end 13 of truck frame 11 so that it will be readily available for loading and discharge of cargo.

When it is desired to carry the loading and discharge mechanism on the truck body frame extension or trailer 20, as illustrated in the drawings, there are mounted on and supported by trailer a loading hopper 70, a discharge accumulator 80, and a discharge chute 90, said hopper 70, accumulator 80 and chute 90 being disposed on said trailer 20 so that, when the rig is in transit, as best illustrated in FIGURES l, 4 and 6 of the drawings, said hopper, accumulator and chute extend generally rearwardly from frame 11 of truck 10, but when loading or discharge of cargo is to be accomplished, as best illustrated in FIGURES 2, 5 and 7 of the drawings, said hopper, accumulator and chute are moved by the elevated pivoting of trailer 20 to operating position closely adjacent to the open end of the mixer drum, in the manner hereinafter described in more detail.

Hopper 70 is mounted rearwardly on trailer 20 above arms 36 by any suitable means, such as by support bracket 72 mounted on rear member 38 and on hopper 70, and by a pair of brackets 74, preferably of inverted Y configuration, mounted on hopper 70 adjacent open loading end 75 of hopper 70 and on arms 32. Said hopper 70 has a loading chute 76 formed thereon, said hopper 70 and loading chute 76 being positioned on trailer 20 so that, when trailer 20 is swung upwardly to loading and discharge position, hopper 70 will be substantially vertically disposed adjacent open end 64 of drum 60, with open end 75 of hopper 70 somewhat above open end 64 of drum 60, and with loading chute 76 projecting into open end 64 of drum 60 so that the aggregate cargo can be easily disposed in drum 60.

Discharge accumulator 80 is mounted on trailer 20 adjacent hopper 70 and is disposed between arms 34 and arms 32. Accumulator 80 may be mounted on trailer 20 by any suitable means, such as by disposing its upper end 82 in a ring 84 and mounting said ring 84 on brackets 74 and additionally, if desired, mounting it on arms 34 as at 85. Accumulator 80 may have external annular rings 86, spaced apart from each other adjacent lower open end 87, the space between said rings 86 serving as a track for trolleys 88 to which the upper end 92 of discharge chute 90 is pivotally attached.

Intermediate the upper end 92 and the lower end 93 of discharge chute 90 is a pivotal mounting 94. A hydraulic cylinder 95 is pivotally mounted adjacent the rear end 13 of frame 11 of truck 10, and a piston rod 96 protrudes from cylinder and has its free end attached to chute 90 at said pivotal mounting 94.

A trunnion 100 is mounted on a cross-beam 101 between arms 30 of trailer 20 intermediate the ends of said arms 30. A trunnion 102 is mounted on body frame 11 of truck 10 adjacent the rear end 13 of frame 11. A hydraulic cylinder 104 is pivotally mounted at one end 105 thereof to said trunnion 102. A piston 106 is slidably disposed in cylinder 104, and a piston rod 107 is mounted on piston 106 and projects from the opposite end 108 of cylinder 104, and the free end of said piston rod 107 is pivotally connected to said trunnion 100.

As illustrated in FIGURE 8 of the drawings, a hydraulic fluid pump is provided. A first hydraulic fluid pressure line 122 leads from pump 120 to a tank reservoir 124. A second hydraulic fluid pressure line 126 leads from reservoir 124 to a hydraulic fluid directional control valve 128. A third hydraulic fluid pressure line 130 leads from pump 120 to valve 128. A fourth hydraulic fluid presure line 132 leads from valve 128 to a first port 134 in cylinder 104, said first port 134 being disposed adjacent to end 105 of cylinder 104, and between piston 106 and said end 105 so as to provide hydraulic fluid access to the interior of cylinder 104 in that area. A fifth hydraulic fluid pressure line 136 leads from valve 128 to a second port 138 in cylinder 104, said second port 138 being disposed adjacent to end 108 of cylinder 104, and between piston 106 and said end 108 so as to provide hydraulic fluid access to the interior of cylinder 104 in that area.

A hydraulic accumulator 140 may be provided. Said accumulator 140 contains a gaseous element 142, and a sixth hydraulic fluid pressure line 144 leads from accumulator 140 to a third port 146 in cylinder 104, said third port 146 being disposed, similar to first port 134, adjacent to end 105 of cylinder 104, and between piston 106 and said end 105.

In the alternative forms of construction of the truck body frame extension or semi-trailer illustrated in FIG- URES 9-12, inclusive, of the drawings, in lieu of swivel pin 42, a vertically, downwardly directed, fixed pin 200 is centrally mounted on cross-beam 40, or alternatively, is mounted on a frame 202, in turn mounted on crossbeam 40 and extending downwardly therefrom. An axle 204 is transversely mounted at the lower end of pin 200 at substantially the center of said axle 204. Standard steering wheel king pins 206 are provided at the ends of axle 204, and wheels 208 are suitably mounted on king pins 206. Tie arms 208 are connected to said king pins 206 and said wheel mountings, and a tie rod 210 connects said tie arms 208, so that a standard steering wheel assembly is provided, and said wheels 208 will turn as a unit.

In the second alternative form of the device illustrated in FIGURE 12 of the drawings, a standard hydraulic steering mechanism 220 may be mounted on tie arms 208. Although not illustrated in the drawings, it will be readily understood that said hydraulic steering mechanism may be operated by a steering wheel accessibly mounted on trailer 20, or may be connected by hydraulic fluid pressure lines to the normal hydraulic steering mechanism of truck 10, so that hydraulic steering by the driver of steering wheels 14 will also provide hydraulic steering by him of Wheels 208.

When the transit mixer is in transit, piston rod 107 is extended, by hydraulic pressure in cylinder 104, between end 105 of cylinder 104 and piston 106, so that trailer 20 is in following position behind truck 10, and the trailer wheels are in contact with the ground 37, and the weightload is distributed over the entire combination of truck frame 11 and trailer 20. As the trailer mixer progresses along its way, by the action of hydraulic accumulator 140, piston rod 107 will be either further extended or retracted, as ground pressure on wheels 50 decreases or increases, so that wheels 50 will follow the varying contours of the ground 37 (spring action and shock absorbing of trailer 20 being thus effectively provided, and weight-load distribution is maintained).

Operation of pump 120 and adjustment of valve 128 will permit high pressure hydraulic fluid to flow into cylinder 104 between end 105 and piston 106, to move piston 106 toward end 108 of cylinder 104, and thus to extend piston rod 107 to bring the trailer wheels into ground contact, and maintain them in ground contact, variations in ground pressure being compensated for by accumulator 140.

Additionally, when the transit mixer is in the position illustrated in FIGURES l, 4 and 6 of the drawings, open end 64 of drum 60 will be clear of impediments, and accessibly open to view, so that, if drum 60 is loaded with cargo, the aggregate mix in drum 60 may be readily, visually inspected, tested, or sampled, to determine, for instance, the slump of the cargo, without the normal requirement of cargo discharge before adequate slump tests may be performed. Furthermore, if drum 60, in that position of the transit mixer, is empty of cargo, ready access to open end 64 will permit easy cleaning of the interior of drum 60, as by a hose. Similarly, because under these conditions, hopper 70, discharge accumulator 80, and discharge chute 90, mounted as they are on trailer 20, are accessibly positioned relatively close to the ground 37 and away from other obstructions, they may be readily cleaned, say, by a man standing on the ground 37 and equipped with a hose.

When drum 60 is to be loaded or discharged, further adjustment of valve 128 will permit high pressure hydraulic fluid to flow into cylinder 104 between end 108 and piston 106, to move piston 106 toward end 105 of cylinder 104, and thus retract piston rod 107 so as to cause trailer 20 to pivot on body frame 11 and swing upwardly, until hopper 70 and discharge accumulator 80 are in proper operative position adjacent open end 64 of drum 60. If discharge is to be accomplished, discharge chute 90 will then be positioned relative to discharge accumulator 80, by operation of cylinder 95, to direct discharged cargo in any desired direction.

Because in the first form of the device, axle 48 is transversely mounted on swivel pin 42, and because trailer 20 is connected to body frame 11 of truck for pivotal elevation, but not for lateral movement relative to frame 11, when steering wheels 14 are turned, the entire transit mixer will turn in the radius illustrated in FIGURE 3 of the drawings, and trailer will not separately follow a wider radius of turn.

Similarly, in the alternative forms of the wheel assembly of the trailer illustrated in FIGURES 9-12, inclusive, of the drawings, the radius of turn of the device will be similarly controlled.

Although the invention has been herein shown and described in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims so as to embrace any and all equivalent structures and devices.

What is claimed is:

l. A transit mixer which comprises: a truck; a rotatable mixer drum mounted on said truck, said drum having an open cargo loading and discharge end disposed rearwardly on said truck; a trailer pivotally mounted on said truck; and elevatable means mounted on said trailer for loading cargo into said drum and discharging cargo from said drum, said means being adapted to be elevated and brought into close proximity to the open end of said drum by upward swinging of said trailer during loading and discharge operations.

2. A transit mixer as defined in claim 1, including a hydraulic cylinder and piston assembly mounted on said truck and connected to said trailer so as to maintain weight distribution over said truck and said trailer, so

as to maintain said trailer in contact with the ground during transit, and so as to swing said trailer upwardly for loading and discharge of cargo into and out of said drum.

3. A transit mixer as defined in claim 1, wherein said trailer comprises: a first pair of substantially parallel arms pivotally mounted on said truck, extending rearwardly therefrom and upwardly inclined; a second pair of substantially parallel, rearwardly extending and downwardly inclined arms integrally formed with said first pair of arms at an obtuse angle; a third pair of arms extending rearwardly in converging relationship to each other, upwardly inclined and integrally formed with said second pair of arms; and a fourth pair of substantially parallel arms integrally formed with said third pair of arms and extending rearwardly therefrom substantially parallel to the ground when the transit mixer is in transit position.

4. A transit mixer as defined in claim 3, including a downwardly directed pin supported by said fourth pair of arms; an axle transversely mounted on said pin; and ground-contacting wheels mounted on said axle so as to support the rear of said trailer.

5. A transit mixer which comprises: a truck having forward steering wheels mounted on a forward axle, and rear ground contacting wheels mounted on rear axles; a rotatable mixer drum mounted on said truck, said drum having an open end disposed rearwardly on said truck adjacent the vertical plane of the rear of said truck; a trailer pivotally mounted at the rear of said truck; a pin mounted on and depending from said trailer; a transverse axle mounted on said pin; a pair of wheels mounted on said axle so as to support said trailer on the ground during transit; and elev-atable means mounted on said trailer for loading cargo into said drum and discharging cargo from said drum, said means being adapted to be elevated clear of the ground and brought into close proximity to the open end of said drum by upward swinging of said trailer during loading and discharge operations.

6. A transit mixer as defined in claim 5, wherein said means for loading cargo into and discharging cargo from said drum comprises: a loading hopper mounted rearwardly on said trailer; a loading chute mounted on said loading hopper so as to be disposed in the open end of said drum when said trailer is swung upwardly; a discharge accumulator mounted forwardly of said hopper so as to be disposed closely adjacent to the open end of said drum, below said hopper, when said trailer is swung upwardly; and a discharge chute adjustably mounted forwardly of said accumulator so as to be disposed in cargo discharge position adjacent to and below said accumulator when said trailer is swung upwardly.

7. A transit mixer as defined in claim 6, including a hydraulic cylinder pivotally mounted at one end thereof to said truck adjacent the rear end of said truck; and a piston rod protruding from said cylinder, the free end of said piston rod being pivotally connected to said trailer, so that, upon actuation of said cylinder in one direction, said piston rod will be extended to provide weight distribution over said truck axles and said trailer axle, and to maintain said trailer in extended, ground contacting position behind said truck, and upon actuation of said cylinder in the other direction, said piston rod will be retracted to swing said trailer upwardly and bring said hopper, loading chute, accumulator, and discharge chute, into elevated operative position adjacent the open end of said drum.

8. A transit mixer which comprises: a truck having a body frame; steering wheels mounted forwardly on said body frame; ground-contacting wheels mounted rearwardly on said body frame; a rearwardly disposed and rearwardly, upwardly inclined, rotatable mixer drum mounted on said truck, said :drum having an elevated open end disposed adjacent the vertical plane of the rear of said body frame; a trailer pivotally mounted on said body frame at the rear of said body frame; a swivel pin mounted on and depending from said trailer; a transverse axle mounted on said swivel pin; a pair of wheels mounted on said axle and adapted to contact the ground when said transit mixer is in transit position; means mounted on said trailer for loading cargo into said drum and discharging cargo from said drum through the open end of said drum; and means mounted on said body frame and on said trailer for pivotally elevating said trailer and for bringing said loading and discharge means into close proximity to the open end of said drum for loading cargo into and discharging cargo from said drum.

9. A transit mixer as defined in claim 8, wherein said means for loading cargo into and discharging cargo from said drum comprises: a loading hopper mounted rearwardly on said trailer; a loading chute mounted on said loading hopper so as to be disposed in the open end of said drum when said trailer is pivotally elevated; a discharge accumulator mounted forwardly of said hopper so as to be disposed closely adjacent to the open end of said drum, below said hopper, when said trailer is pivotally elevated; and a discharge chute adjustably mounted forwardly of said accumulator so as to be disposed in cargo discharge position adjacent to and below said accumulator when said trailer is pivotally elevated.

10. A transit mixer as defined in claim 9, wherein the means for pivotally elevating said trailer and bringing said loading and discharge means into close proximity to the open end of said drum comprises: a hydraulic cylinder pivotally mounted at one end thereof to said body frame adjacent the rear end of said body frame; and a piston rod protruding from said cylinder, the free end of said piston rod being pivotally connected to said trailer, so that, upon actuation of said cylinder in one direction, said piston rod will be retracted to swing said trailer upwardly and bring said hopper, loading chute, accumulator, and discharge chute, into elevated position adjacent the open end of said drum.

11. A transit mixer as defined in claim 10, including means pivotally mounted on said body frame and on said discharge chute for adjustably disposing said discharge chute in relation to said discharge accumulator.

12. A transit mixer as defined in claim 11, wherein said means for adjustably disposing said discharge chute comprises a hydraulic cylinder and piston rod assembly.

13. A transit mixer which comprises: a truck having a body frame; steering wheels mounted forwardly on said body frame; ground contacting wheels mounted rearwardly on said body frame; a rearwardly disposed and rearwardly, upwardly inclined, rotatable mixer drum mounted on said truck, said drum having an elevated open end disposed adjacent the vertical plane of the rear of said body frame; a trailer pivotally mounted on said body frame at the rear of said body frame; a pin mounted on and depending from said trailer; a transverse axle mounted on said pin; a pair of trailer wheels mounted on said axle; means mounted on said body frame and on said trailer for maintaining said trailer wheels in contact with the ground when said transit mixer is in transit position; means mounted on said trailer for loading cargo into said drum and discharging cargo from said drum through the open end of said drum; and means mounted on said body frame and on said trailer for pivotally elevating said trailer and for bringing said loading and discharge means into close proximity to the open end of said drum for loading cargo into and discharging cargo from said drum.

14. A transit mixer as defined in claim 13, wherein the means for maintaining said trailer wheels in contact with the ground during transit comprises: a hydraulic cylinder pivotally mounted at one end thereof to said body frame adjacent the rear end of said body frame; a piston slidably disposed in said cylinder; and a piston rod connected to said piston and protruding from said cylinder, the free end of said piston rod being pivotally connected to said trailer, so that, upon actuation of said cylinder in one direction, said piston rod will be extended to maintain said trailer in extended, ground-contacting position behind said body frame.

15. A transit mixer as defined in claim 14, including a hydraulic accumulator mounted on said body frame and connected to said hydraulic cylinder so as to cushion the hydraulic action of said cylinder when the transit mixer is in transit, and maintain contact of the trailer wheels with the ground regardless of ground grade variations.

16. A transit mixer which comprises: a truck having a body frame; steering wheels mounted forwardly on said body frame; ground-contacting wheels mounted rearwardly on said body frame; a rearwardly disposed and rearwardly, upwardly inclined, rotatable mixer drum mounted on said truck, said drum having an elevated open end disposed adjacent the vertical plane of the rear of said body frame; a trailer pivotally mounted on said body frame at the rear of said body frame; a pin mounted on and depending from said trailer; a transverse axle mounted on said pin; a pair of trailer wheels mounted on said axle; means mounted on said trailer for loading cargo into said drum and discharging cargo from said drum through the open end of said drum; and a reciprocal hydraulic cylinder and piston rod assembly pivotally mounted on said body frame and on said trailer for maintaining said trailer wheels in contact with the ground when the transit mixer is in transit, and for pivotally elevating said trailer and bringing said loading and discharge means into close proximity to the open end of said drum when loading and discharge of cargo is to be accomplished.

17. A transit mixer as defined in claim 16, wherein said trailer wheels are steerable.

18. A motor vehicle which comprises: a truck having a body frame, forward steering wheels, and rear ground contacting wheels; a rotatable mixer drum mounted on said truck; a truck body frame extension pivotally mounted on the body frame of said truck rearwardly of the wheels of said truck, and extending rearwardly from said truck body frame; ground contacting wheels mounted on said truck body frame extension and disposed to turn when the steering wheels of the truck are turned so as to maintain a turning radius for said truck and said body frame extension; and means interconnecting the body frame of said truck and said truck body frame extension for elevating said truck body frame extension.

19. A motor vehicle which comprises: a truck having a body frame, forward steering wheels, and rear ground contacting wheels; a rotatable mixer drum mounted on said truck; a truck body frame extension pivotally mounted on the body frame of said truck rearwardly of the wheels of said truck, and extending rearwardly from said truck body frame; ground contacting wheels mounted on said truck body frame extension and disposed to turn when the steering wheels of the truck are turned so as to maintain a turning radius for said truck and said body frame extension; means inter-connecting the body frame of said truck and said truck body frame extension for elevating said truck body frame extension; and a recipro eating hydraulic cylinder and piston assembly pivotally mounted on the truck body frame and on the body frame extension and disposed so as to maintain the body frame extension in contact with the ground during transit and provide weight distribution over said body frame exten sion and said truck.

References Cited in the file of this patent UNITED STATES PATENTS 3,019,002 Prichard Jan. 30, 1962 FOREIGN PATENTS 114,850 Australia Mar. 6, 1942

Claims (1)

1. A TRANSIT MIXER WHICH COMPRISES: A TRUCK; A ROTATABLE MIXER DRUM MOUNTED ON SAID TRUCK, SAID DRUM HAVING AN OPEN CARGO LOADING AND DISCHARGE END DISPOSED REARWARDLY ON SAID TRUCK; A TRAILER PIVOTALLY MOUNTED ON SAID TRUCK; AND ELEVATABLE MEANS MOUNTED ON SAID TRAILER FOR LOADING CARGO INTO SAID DRUM AND DISCHARGING CARGO FROM SAID DRUM, SAID MEANS BEING ADAPTED TO BE ELEVATED AND BROUGHT INTO CLOSE PROXIMITY TO THE OPEN END OF SAID DRUM BY UPWARD SWINGING OF SAID TRAILER DURING LOADING AND DISCHARGE OPERATIONS.

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