Apparatus for mounting and demounting a vehicle body

Apparatus for changing bodies on a vehicle includes a long beam platform pivotally connected at its rearward end to that of the vehicle chassis, a hoist to pivot the platform and a pair of hydraulic cylinder winches having a set of multiwrap sheaves at either end and mounted to both sides of the platform. The sheaves are multiwrapped with a cable secured at one end and securable to the truck body at the other end. The cylinders extend in the direction of loading to maximize travel efficiency and eliminate the need for an idler sheave. Retractable locking means are provided on the platform for locking the body into place. By operation of the hoist and winches, the vehicle body may be quickly and safely mounted onto or demounted from the platform whether loaded or unloaded.

This invention relates to apparatus for changing vehicle bodies. More 
particularly, this invention relates to apparatus connectable to the 
chassis of a vehicle for easily mounting a body on or demounting a body 
from the chassis. 
Trucks, except for certain light weight types, are generally not 
mass-produced by assembly line techniques. Rather, each truck is usually 
custom built by a final stage manufacturer who mounts the body to the 
chassis and adds various customizing features to the finished product at 
the customer's request. Because of this, the customer often has the 
opportunity to choose from a wide variety of body styles, shapes and sizes 
and from a wide variety of chassis-cab models which are mass produced by 
large relatively centralized corporations using assembly line techniques. 
The mass-produced chassis is comprised of a cab, longitudinal side frame 
members extending from behind the cab, engine and axles. Although the 
chassis (i.e., chassis-cab) is only one component of the finished vehicle, 
it usually constitutes the major expense in the overall cost. 
The efficacy of being able to use multiple bodies with a single chassis is 
well known. For example, in agriculture, the ability to be filling one or 
more grain or other produce bodies in the field while a filled body is 
being hauled to the storage facilities by the chassis, obviously reduces 
the number of chassis that are needed, and thus maximizes profits. In 
addition, many agricultural or other industrial operations are 
multifacited. Thus, for example, the ability to easily and rapidly mount 
and demount a body onto and from a chassis means that the vehicle can be 
quickly converted from a grain or produce hauler, into a flat bed, live 
stock rack, van body or machinery platform, etc., without the expense 
and/or loss of time normally resulting from having to take the truck into 
the shop for conversion, or the need to purchase a chassis for each body 
style desired. 
One of the most significant problems faced in designing any mounting 
apparatus that is to be a part of the finished vehicle is adequate 
strength. While empty bodies are usually relatively light, when loaded 
these bodies often carry several tons. Because of the manner in which 
chassis are designed, there is usually little excess space within which to 
locate the mounting apparatus. Thus, the equipment employed must be 
strong, efficient and yet capable of being installed within the available 
space. 
Another problem attendant the design of any such mounting apparatus is one 
of safety, particularly highway safety. First and foremost the body, while 
readily portable, must be securely locked into place when being hauled by 
the chassis. 
In addition to highway safety, there is also, of course, the need to insure 
the safety of the operator during mounting and demounting. Uncontrolled 
and exposed draw cables, particularly when used with drum winches or 
centrally extending cylinder winches currently employed in known devices 
by loading equipment can present a significant safety problem if the 
cables snap or come loose during the mounting or demounting operations. 
This hazard becomes particularly acute when mounting or demounting a 
heavily loaded body as contemplated by this invention. 
Yet another problem attendant the art is the need to obtain travel 
efficiency. Any devices employed must be able to move a minimum distance 
which results in a maximum unloading or loading distance affect. While 
related to the space and strength problem heretofore discussed, this also 
becomes a part of the economic problem, i.e., the mandate that the system 
not be so complex as to be too expensive or too unreliable for its 
intended purpose. 
From the above it can be seen that there exists a need in the art for a 
mechanism which can easily and quickly mount or demount a body onto or 
from a chassis and yet which is safe, effective, reliable, and economic, 
but which does not consume undue space and securely locks the body to the 
chassis. It is the purpose of this invention to fulfill this and other 
needs apparent to the skilled artisan once given the following detailed 
description of the invention. 
Generally speaking, this invention fulfills the abovedescribed needs and 
eliminates the aforesaid problems by providing an apparatus for mounting 
or demounting a vehicle body onto or from a vehicle chassis which 
comprises a platform for supporting the body, means for pivotally 
connecting the platform to the vehicle chassis, means for rotating the 
platform about the pivotal connection means, a winch means for 
controllably moving the body off of or onto the platform, and means for 
securing the body to the platform, the winch means comprising a pair of 
hydraulic cylinder winches having at either end a multiwrap set of sheaves 
and a cable multiwrapped about the sheaves, one end of the cable being 
secured and the other end being attached to means for removably securing 
it to the body. 
In certain preferred embodiments of this invention the pivot means is a 
hoist and both winch and hoist are hydraulically operated. In further of 
these embodiments the platform is comprised of two longitudinal slide 
beams pivotally attached to the two longitudinal side chassis frame 
members and spaced so as to align in sliding fashion with attachments to 
the long sills of the body. In such embodiments there is preferably 
provided a multiwrap hydraulic winch attached to each of the longitudinal 
slide beams and covered in a manner to minimize cable exposure. In 
addition the hydraulic cylinders are located to elongate in the direction 
in which the body is drawn onto the platform, thus maximizing travel 
efficiency and eliminating the need for an idler sheave. Guide means are 
preferably provided for the hydraulic cylinder sheaves during the 
extending operation, thereby to maximize the efficiency and safety of the 
mounting or demounting operation. In other preferred embodiments the means 
for securing the body to the platform are retractable hydraulically 
operated locking means which, when locked, insure that the body is safely 
secured to the vehicle chassis when it is hauling the body or during a 
dumping operation. The apparatus of this invention finds particular 
utility in the truck art and more particularly in the heavy-duty truck art 
.

With reference to the drawings, there is illustrated a typical truck 
chassis 1 conventionally equipped with a cab 3, side tanks or tool box 5, 
drive shaft 7, a tandem rear axle assembly 9, dual wheels 11, a pair of 
longitudinally extending frame members 13 and reinforcing cross members 
15. 
Attached to chassis 1 is an apparatus in accordance with this invention for 
safely and effectively mounting and demounting body 17 onto and from 
chassis 1 regardless of whether body 17 is loaded or unloaded. As 
illustrated best in FIG. 3 and as more fully discussed hereinafter, the 
apparatus also includes a means 19 for securing body 17 in place during 
hauling and/or dumping. 
The apparatus illustrated generally includes a platform 21 comprised of a 
pair of longitudinally extending slide beams 23 and reinforcing cross 
beams 25. Platform 21 is pivotally connected to chassis frame members 13 
by pivot pin (and shaft) connection 27. Platform 21 is pivoted about 
connection 27 by a hoist 29. 
Hoist 29 may be of any conventional design. For the purposes of this 
invention, hydraulic hoists of the power-up/power-down type are preferred. 
Such hoists are operated by conventional hydraulic systems (not shown for 
convenience) whose hydraulics are pressurized either from a conventional 
power take-off device associated with the transmission or by a separate 
unit. A preferred example of a hydraulic hoist readily adaptable for use 
with the illustrated apparatus is a LO-BOY hoist manufactured by Crysteel 
Mfg., Inc., of Lake Crystal, Minn. 
Longitudinal beams 23 extend rearwardly of chassis frame member 13 a 
distance sufficient so that when hoist 29 is fully extended to give pivot 
platform 21 its maximum degree of rotation (e.g., about 60.degree. from 
the horizontal), the rearward ends 31 of beams 23 are only a few inches 
off the ground. This facilitates primarily the mounting operation. Beams 
23 are preferably tubular and rectangular in cross-section and have 
attached to their outboard sides hydraulic cylinder winches 33. This may 
be accomplished by any convenient technique such as the support technique 
as illustrated. Such a support includes a pair of lateral plates 35 and a 
diagonal plate 37. 
The hydraulic cylinder winches 33 may be of any conventional design. For 
the purposes of this invention their design is arranged to maximize travel 
efficiency. Thus, while such winches are conventionally comprised of a 
hydraulic cylinder 39, a shaft and cross-head 41 and a pair of sheaves 43a 
and 43b, sheaves 43 are specifically designed to take the necessary number 
of wraps of cables 45 to provide sufficient length of travel for effective 
operation. In addition, cable 45 is connected to winch 33 at a stationary 
anchor and winch 33 is directed so that cylinder shaft 41 extends in the 
direction of mounting. Thus, by providing sheaves 43b with one or more 
wraps than sheaves 43a, travel efficiency is maximized. Also the usual 
need for an idler sheave is eliminated, since all sheaves become working 
sheaves. 
While this configuration may be varied and redirected to meet particular 
situations, it is found that for most purposes mounting a loaded body 17 
will require the most power and that for most purposes at least two wraps 
of sheave 43a and at least three of 43b provide the necessary efficiency 
for rapid, yet safe, mounting (e.g., 20 ft. of cable travel for 40 inches 
of cylinder stroke). In addition, by commencing the wrapping of cable 45 
on the outboard side of its connection and providing the requisite number 
of wraps (e.g., two on 43a, three on 43b), a significant portion of the 
final length of cable 45 extending to hook 47 on body 17 resides between 
winch 33 and beam 23, thus serving as a shield if breakage during 
operation should occur and as a control guide for assuring proper aligning 
of body 17 with beams 23. 
During operation, hydraulic cylinder shafts 41 are held in line by slide 
bars 49 which form grooves 51 in which sheave axis pins 53 reside. Plates 
55 support the ends of slide bars 49. Cylinder shaft 41 extends a distance 
sufficient to bring body locking groove 57 and stop pin 59 together. As an 
additional safety feature there is provided an "L" beam 61 which extends 
around the winch assembly 33 along a substantial portion of the length of 
beams 23. Not only does beam 61 inhibit the whip action of cable 45 should 
it break during the mounting or demounting operation, but it also serves 
to protect the winch assembly from foreign objects such as stones, mud, 
etc. 
In order to facilitate mounting and demounting, body 17 is provided with a 
means for aligning it with beams 23 and readily moving it therealong. 
While beam 23 may be provided with rollers or other expensive apparatus, 
in the embodiment shown, beam 23 is a single, yet effective slide beam 
upon which body 17 slides during mounting or demounting. 
The means on body 17 for aligning it with beams 23 generally comprise an 
"L"-shaped slide plate 65 and an elevating "C" beam 67 connected to the 
inboard side of long sill 63. The thickness of the vertical leg of plate 
65 provides the necessary close but adequate spacing between platform beam 
23 and its adjacent body sill 63 while the depth of the cavity in beam 67 
provides the necessary elevation to the lower horizontal wall of sill 63 
so as not to interfere with any of the winch platform structures. Plate 65 
emerges from the forward end of body 17 and is curved upward, thereby to 
provide a starting runway for initiation of the mounting operation. While 
not always necessary, either or both of the proximal surfaces during 
sliding of beams 23 and plates 65 may be greased or otherwise lubricated 
for better sliding action, where beam 23 is a simple sliding beam. 
It is important that body 17 be tightly locked into place once it is 
mounted on platform 21. This is not only important for safety during 
hauling but at times body 17 may be a dump body, i.e., unloadable by 
raising hoist 29 and dumping the contents from the rear of body 17. While 
pins 59 and cables 45 provide a modicum of securing ability, it is 
preferred to have additional means for achieving a true locking function 
as well. In this regard, such means must not only be effective, but should 
preferably be easily and automatically engaged or retracted, so as to 
interfere as little as possible with the mounting and demounting process. 
Securing means 19, as illustrated in detail in FIG. 3, fulfills this need. 
Securing means 19 is comprised of a double acting, floating hydraulic 
cylinder 69 having an extendible-retractable shaft and yoke 71a and 71b. 
Yokes 71a and 71b are aligned with hollow tubes 73a and 73b respectively, 
located in and extending through beams 23. Long sills 63 have extending 
therethrough hollow tubes 75a and 75b of similar interior diameter as 
tubes 73a and 73b. Tubes 75a and 75b are brought into alignment with tubes 
73a and 73b when body 17 is fully mounted on platform 21. Yokes 71a and 
71b are connected to locking heads 77a and 77b which, as illustrated in 
the cutaway left hand side of FIG. 3, slidably reside in tubes 73a and 73b 
when in unlocked position, and which upon actuation to lock body 17 into 
place, extend into tubes 75a and 75b (dotted line). Slide grooves 79 are 
provided in tubes 73a and 73b, and pins 81 are provided in heads 77a and 
77b. Pins 81 reside in their respective grooves 79 thus to form stop 
limits upon the distance of extension and retraction of yokes 71a and 71b. 
Generally, the outboard ends of grooves 79 should be such that pins 81 
contact them just before heads 77a and 77b emerge from tubes 75a and 75b 
respectively. 
Means 19 may be actuated by any conventional hydraulic system. As stated 
above it is preferred that the cylinder 69 be of the floating type such 
that for example yoke 71b would first be actuated, and when it hits its 
stop limit (as when pin 81 contacts the outboard end of groove 79), yoke 
71a is actuated. The hydraulics of such a system are conventional and may 
be automatically operated from any convenient and safe control location. 
The power for the hydraulics may be obtained from the same source as used 
for hoist 29 and/or winches 33 or from a separate source. A conventional 
power take-off device associated with the truck's transmission in a known 
manner is a convenient technique for obtaining the necessary power. 
OPERATION 
The illustrated device may be operated to easily and safely mount or 
demount a body 17 with respect to chassis 1. FIG. 1 illustrates the 
device, chassis 1 and body 17 in a partially mounting or demounting 
posture. A description of an advantageous mounting technique is as 
follows: 
Assume a loaded grain body 17 is resting in a field awaiting to be picked 
up and hauled to the granary. Body 17 is equipped with the illustrated 
long sills 63 and slide plates 65 elevated to the appropriate height by 
"C" beams 67. 
Empty chassis 1 having attached thereto the mounting apparatus as 
illustrated is aligned just ahead of body 17 with hoist 29 in fully raised 
position. In this position ends 31 of beams 23 are substantially aligned 
with their respective slide plates 65 attached to body sills 63. 
Extendable cylinder shafts 41 are in their most retracted position, and 
cables 45 are now connected to hooks 47 on either side of sills 63. 
With the chassis (truck) in neutral and without holding the brakes, the 
hydraulics of winches 33 are actuated to extend cylinder shafts 41 thus 
tightening cables 45 and pulling chassis 1 backward until ends 31 of beams 
23 contact the curved upward portion of slide plates 65. 
Continued extension of cylinder shafts 41 causes body 17 to slide upward 
onto beams 23 of platform 21. As this occurs hoist 29 is powered downward 
helping to lift body 17 from the ground. (This is the position shown in 
FIG. 1). When the front of body 17 is about as high as frame 13, hoist 29 
is again powered until the angle of beams 23 and sills 63 are the same. 
(During tne entire process the angle usually will not exceed 18.degree.). 
At this point winch 33 is further actuated to bring body 17 aboard, 
allowing chassis 1 to roll back freely under body 17 until the rear of 
body 17 leaves the ground. As body 17 nears the front of platform 21, 
hoist 29 is powered down all the way, and body 17 is further winched 
aboard until locking grooves 57 engage pins 59. At this point tubes 73 and 
75 are aligned and by actuation of the hydraulics in cylinder 69 yokes 71 
are extended into tubes 75, securely locking body 17 to chassis 1. 
After plugging in the required electrical wiring for lights, etc. (not 
shown), the grain-filled body may be safely hauled to the granary, while 
other bodies remain in the field to be filled. Typical mounting time 
elapsed is about ten minutes. In the mounted and locked position the body 
and chassis may be operated as any conventional body-hoist-chassis 
combination including dumping the grain from a rear door of body 17 after 
raising the hoist in a conventional dumping technique. 
Once returned to the field, the now empty body 17 may be readily demounted 
from chassis 1 for reloading and the pick up of another loaded or 
different type of body by following the following simple procedure: 
Firstly, the hydraulics of locking cylinder 69 are actuated to withdraw 
both heads 77a and 77b from their respective body tubes 75a and 75b. Hoist 
29 is then actuated and raised to about a 20.degree. angle. The hydraulics 
of winch cylinders 39 are then actuated to retract shafts 41 until the 
rear of body 17 is on the ground. Then in a simultaneous operation, more 
of cables 45 is let out while chassis 1 is eased forward and hoist 29 is 
raised to its fully elevated position. With body 17 now completely at rest 
on the ground, cables 45 may be removed from hooks 47. The wiring sockets 
(not shown) will have unhooked themselves automatically. 
Once given the above description many other features, modifications and 
improvements will become apparent to the skilled artisan. Such other 
features, modifications, and improvements are, therefore, considered to be 
a part of this invention, the scope of which is to be determined by the 
following claims: