Side loading refuse collection vehicle arm restraint

A side loading refuse collection vehicle having a carriage slidably mounted on a track and pivotally carrying a lift arm assembly including refuse container grabbing and dumping apparatus for grabbing a refuse container, lifting it and dumping it into the body of the vehicle includes a keeper plate secured to the carriage and a detent latch pivotally mounted on the frame for seizing and holding the keeper selectively. The carriage is slidably driven by a hydraulic cylinder assembly to extend and retract the carriage relative to the vehicle, and whenever the hydraulic cylinder assembly is actuated by an operator control switch the latch disengages from the keeper. When the hydraulic cylinder assembly is not actuated, the latch engages and holds the keeper and thereby prevents the lift arm from being flung outwardly in the event of a failure in the hydraulic cylinder assembly system.

BACKGROUND OF THE INVENTION 
This invention relates to refuse collection vehicles of the type having an 
arm extendible from the body of the vehicle and having a refuse container 
grabber arm at the end for grasping, lifting and dumping a container into 
the vehicle, and more particularly to apparatus for preventing the arm 
from extending away from the vehicle beyond a safe distance in the event 
of a failure in the arm extension drive system. 
Refuse collection vehicles are known which have an arm selectively 
extendible from the body of the vehicle and having grabbing or grasping 
apparatus at the end of the arm remote from the vehicle for clamping 
firmly about a refuse container. Associated with the arm is means for 
lifting the end of the arm including the grasping apparatus and means for 
dumping the container into a hopper at the top of the vehicle body. Such 
vehicles, known in the art as side loaders, have the obvious advantage in 
that only one person, to wit, a driver is necessary to collect refuse from 
a substantial number of dwellings or the like. The means for extending the 
arm includes an elongated hydraulic cylinder with an extendible piston rod 
which permits the arm to be extended up to approximately 8 feet from the 
body so that a refuse container may be picked up in tight or difficult 
locations such as on the sidewalk of a street while the refuse vehicle may 
be prevented from getting close to the sidewalk because of parked vehicles 
and the like. The arm may be retracted filly so that the grasping 
apparatus is disposed substantially within the lateral confines of the 
body of the vehicle or in close proximity thereto thereby permitting the 
vehicle to be driven at highway speeds when necessary, such as when 
traveling to a dump site or the like. The arm may also be positioned 
between these extremes, such as when the vehicle is driven at relatively 
slow speeds between adjacent refuse containing stations, e.g. between 
adjacent dwellings having refuse containers, and when the vehicle turns a 
street corner between such adjacent dwellings. 
A potential problem associated with the extendible lift arm is that which 
may occur should there be a failure of the arm extension drive means, e.g. 
the extension cylinder, the hydraulic circuit therefor or the electrical 
circuit controlling the operation of the hydraulic system. In such a 
situation the vehicle may be stopped by the driver of the vehicle if the 
arm is extended far enough from the vehicle to be seen from the cab by the 
driver. However, if the arm is not extended far enough so as to be 
viewable by the driver, the driver may not be aware of such a failure and 
may drive the vehicle at speeds or conditions that would be hazardous to 
life and property. For example, the arm may spring outwardly due to 
centrifugal force while the driver is turning a corner or driving at less 
than relatively high speeds on a street or at high speeds on a highway. 
Should the arm extend in this manner to its full length an obviously 
dangerous situation is presented. 
SUMMARY OF THE INVENTION 
Consequently, it is a primary object of the present invention to provide 
apparatus which precludes the extendible lift arm of a side loader refuse 
collection vehicle from extending beyond a desired amount from the body of 
the vehicle should a failure of the arm extension drive system occur. 
It is another object of the present invention to provide latching apparatus 
for preventing extension of the extendible lift arm of a side loader 
refuse collection vehicle unless the latching apparatus is disengaged, 
such disengagement being only at the control of the driver of the vehicle. 
It is a farther object of the present invention to provide latching 
apparatus for locking the extendible lift arm of a side loader refuse 
collection vehicle in selective retracted positions relative to its fully 
extended position so as to prevent the arm from extending outwardly 
haphazardly should a failure of the arm extension drive system occur. 
Accordingly, the present invention provides a side loader refuse collection 
vehicle having an extendible lift arm carrying at the end thereof refuse 
container grasping apparatus for grasping a refuse container, the arm 
being extendible by operator controlled drive means, and the arm having 
latching means associated therewith for locking the arm in selective 
positions less than the fully extendible position, the latching means 
being automatically engagable when the arm is extended outwardly, but the 
latching means being disengaged to permit the arm to be extended outwardly 
only when the arm is operably driven. 
The arm is carried by a slidable carriage driven toward and away from the 
body of the vehicle and is pivotable relative to the carriage to permit 
the grasping apparatus to dump a refuse container into the body of the 
vehicle. The carriage carries a keeper plate which may be seized by a 
latch or detent when the carriage, and thus the arm, is in preselected 
positions as the carriage and arm extend outwardly. The detent is 
pivotally carried on a member fixed relative to the frame of the vehicle 
and is urged toward seizing disposition with the keeper plate, the detent 
being selectively pivoted to overcome the urging force to release the 
keeper plate as the carriage and arm move outwardly. The detent is 
configured to permit the keeper plate to pivot it into disengaging 
relationship as the carriage and the arm retract inwardly, but the latch 
preferably is selectively pivoted to disengagement when the arm is 
selectively moved inwardly. In the preferred form of the invention, the 
keeper plate has a number of latch receiving slots and the detent is 
pivotably moved by a power driven member activated selectively to 
disengage the detent from the keeper plate when the carriage is driven 
outwardly and inwardly. Thus, should the carriage driving system fail and 
the arm urged by centrifugal force or the like outwardly, the detent will 
be received within a slot and be precluded from extending outwardly 
further. The disposition of the slots is such that the arm may be 
precluded from moving beyond approximately 32 inches from the body of the 
vehicle so that it will not result in a hazardous situation.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, FIG. 1 illustrates a side loading refuse 
vehicle 10 conventionally having a cab 12 at the front, a chassis 
including longitudinally extending frame members 14, 16, illustrated in 
FIG. 2, and a refuse receiving body 18 mounted on the chassis spaced 
behind the cab. The body has a refuse receiving hopper 20 at the top 
adjacent the front end and refuse may be deposited into the body by side 
loading apparatus as hereinafter described through the hopper. The refuse 
is there compacted by conventional apparatus within the body and 
eventually expelled at the rear end, preferably by dumping, after the rear 
end 22 is hingedly opened and the body tilted by means of a hydraulic 
cylinder 24 at each side. 
The side loading apparatus comprises a transversely extending track 26 
extending between the sides adjacent the body intermediate the cab 12 and 
the body, the track, as best illustrated in FIGS. 3 and 4, being secured 
to and supported on stanchions 23, 25 secured on plates 27, 29 which are 
in turn secured to the frame members 14, 16. Fastened to the end of the 
track 26 at one side thereof, that side being the side remote from the 
sidewalk on which the refuse containers are located and thus the same side 
as that of the driver, is a small upstanding bracket 28 illustrated in 
FIG. 2. The bracket 28 secures and journally supports the end of a rod 30 
extending from a hydraulic cylinder 32, the cylinder and rod defming an 
extension cylinder assembly. The cylinder 32 is secured to a carriage 
assembly 34 by means of a pair of spaced apart split blocks 36, 38 having 
the lower block being welded to a horizontal plate 40 on the carriage that 
is superposed above the rail and carries a number of rollers (not 
illustrated) disposed about vertical axes and which engage and roll 
against the respective front and rear surfaces of the track 26. The 
carriage assembly also includes a pair of spaced apart upstanding 
standards 42 welded thereto on opposite forward and rearward facing ends, 
only the rear standard being illustrated. Rollers, only a rear set 44, 46 
being illustrated, are connected to front and rear vertical plates 48, 50 
welded to the horizontal plate 40 of the carriage assembly and to both 
standards 42 and are disposed above and below a rail 52 protruding 
forwardly and rearwardly from the track 26 so that the rollers 44, 46 may 
ride on the rails. The carriage assembly is thus slidably mounted for 
riding on the track 26 and may be moved from side-to-side by means of the 
cylinder 32. Since the rod 30 of the hydraulic cylinder assembly is fixed 
against movement sidewise across the vehicle by the bracket 28, the 
cylinder 32 may be driven and thus the carriage assembly secured thereto. 
Pivotally connected for rotation on a journal shaft 54 between the 
standards 42 is an elongated extendible lift arm 56. The arm 56 has a 
first off-set portion 58 with a downward extension 60 at its outer end and 
a second off-set portion 62 with an upward extension 64 at its other end, 
the off-sets being stepped rearwardly relative to the axis of elongation 
of the arm 56. The downwardly extending off-set portion 60 terminates in a 
drop arm assembly 66 which is connected to a rearwardly extending dump arm 
68 which pivotally carries a pair of grabbers 70, 72 for clamping about a 
refuse container as illustrated in FIG. 1. The grabbers 70, 72 have sector 
gears 74, 76 secured on adjacent ends, the gears being in meshing 
relationship. The sector gear 76 has an off-set portion (not illustrated) 
which forms a lever for the sector gear 76 and a stud shaft connected to 
the off-set portion extends upwardly through the dump arm 68 and is 
secured to a lever arm 78. A hydraulic cylinder assembly 80 forming a 
grabber cylinder means is connected at one end to the arm 78 and at its 
other end to a lug 82. When the cylinder 80 is actuated the sector gear 76 
is rotated and the grabbers move relative to each other to grasp or 
release a refuse container. The dump arm 68 is pivotally connected to the 
downward extension 60 of the lift arm 56 for rotation about the journal 
pin 84 disposed in off-set spaced apart blocks 86 secured to the dump arm 
68, the pin 84 having an axis substantially parallel to the axis of 
elongation of the dump arm. A pair of spaced apart lugs 88 secured to the 
dump arm 68 extends in the opposite direction from the blocks 86 and one 
end of a hydraulic cylinder assembly 90 forming a dump cylinder means is 
pivotally connected between the lugs, the other end of the assembly 90 
being connected between another pair of lugs 92 affixed to and extending 
inwardly relative to the downwardly extending off-set portion 60 of the 
lift arm 56. When the cylinder 90 is actuated, the dump arm assembly may 
be rotated relative to the pin 84 and thus the lift arm. 
The upstanding extension 64 of the second off-set portion 62 of the lift 
arm 56 includes as pair of lugs 94 between which one end of a hydraulic 
cylinder assembly 96 forming a lift cylinder means is pivotally connected, 
the other end of the assembly 96 being pivotally connected between a pair 
of lugs 98 secured to the vertical plate 50 and the horizontal plate 40 of 
the carriage assembly 34. When the cylinder 96 is actuated to extend its 
piston, the lift arm assembly including the lift arm 56 and its downwardly 
extending portion 60 together with the dump arm assembly 66 may be pivoted 
about the journal shaft 54 relative to the carriage 34 so that a refuse 
container may be lifted over the hopper 20 and then the dump arm 68 may be 
pivoted- relative to the lift arm 56 to dump the contents of the refuse 
container into the hopper. 
The structure thus far described is now conventional and has been described 
so as to define the environment of the present invention. The present 
invention, as aforesaid, relates to means for locking the arm 56 
automatically in positions less than fully extended so that it may not 
extend further in the event of a failure in the drive cylinder assembly 
30, 32, the hydraulic system associated therewith or the electrical system 
for controlling the hydraulic system. 
To this end, the present invention provides a keeper in the form of a plate 
100 secured as by welding to the rear plate 50 at the underside and 
leading edge of the carriage 34, the plate 100 being approximately 1/2 
inch thick and approximately two feet long, the direction of elongation 
being substantially that of the arm 56. 
Formed in the plate 100 is a plurality of slots, there preferably being 
three slots within the plate, 102, 104, 106, and a fourth slot 108 opening 
at the leading edge of the plate. A detent in the form of a latch 110 is 
pivotally connected by a journal pin 112 between a pair of plates 114, 116 
which are secured below the track 28 to the stanchions 25. The latch 110, 
as illustrated in FIGS. 5 and 6, is a lever having a configuration 
including a hook 118 at one end spaced from the journal pin receiving hole 
119 formed in the crotch between a pair of tines 120, 122 the surface 124 
of the tine 120 externally of the crotch being smoothly contoured so as to 
form a cam-like surface as illustrated in FIG. 6. The latch 110 spaced 
from the hook 118, at the other side of the hole 119 has an arm 126 which 
is pivotally connected to one end of a small pneumatic cylinder assembly 
128, the other end of the assembly 128 being pivotally connected to a pin 
extending between the plates 114, 116. 
The cylinder assembly 128 has a piston which is spring loaded to the 
retracted position so that the latch 110 is disposed in the 
counter-clockwise pivoted position illustrated in FIG. 5, that position 
being such as to engage the hook with the plate 100 and thus the hook may 
enter into the slots 102, 104, 106, 108 selectively depending upon the 
sidewise location of the carriage 34. Thus, when the cylinder assembly is 
in the unactuated condition, the latch 110 seizes the plate 100 and is in 
the locking position. When the carriage 34 and thus the arm 56 is moving 
in the outwardly extending position, the latch 110 may lock with one of 
the slots since the keeper plate 100 at the trailing edge of the slot will 
enter between the tines 120, 122 of the hook 118. If the carriage is 
moving in the inward direction, the plate may ride over the smooth cam 
surface 124 and pivot the latch against the spring load on the piston of 
the cylinder assembly 128. However, it is preferred in such situations to 
actuate the cylinder assembly 128. When the cylinder assembly is actuated 
to extend the piston, the latch 110 is rotated in the clockwise direction 
to the short term position as illustrated in FIG. 5 and the latch is clear 
of the plate 100. This will occur only when the driver actuates the arm 
extension cylinder 32 to move the carriage 34 in either direction. The 
latch 110 may have a small arcuate slot 130 to limit pivotal movement of 
the latch in both directions and to aid in the assembly of the latch 
between the plates 114, 116, there being a small pin 132 fastened between 
the upper and lower plates which is received within the slot 130. 
Additionally a stop block 131 welded between the plates ensures that the 
latch will not pivot too far when in the latched position. 
Associated with the pneumatic cylinder assembly 128, as illustrated in FIG. 
7, is an air valve 134 receiving air from a source 136 conventionally 
within the vehicle 10, the valve having a vent 138 to exhaust the air back 
from the cylinder assembly 128 when the valve is closed. The air valve is 
connected electrically through a junction box 140 to a controller 142 for 
the hydraulic valving 144 controlling the arm extension cylinder assembly 
32, the controller being operated by the driver via a rocker switch 143 
which must be held in either the "in" or "out" position or is biased off. 
When the driver actuates the extension cylinder assembly 32 either in the 
inward or outward direction, the air valve 134 is also opened to actuate 
the pneumatic cylinder assembly 128 to pivot the latch 110 to the 
unlatched position. 
Should a failure in the extension cylinder assembly occur, such as an 
electrical failure, the air valve will be precluded from operating and the 
carriage and arm will be locked by the latch 110. If a hydraulic failure 
or a cylinder drift failure occurs and if the arm is extended beyond 
approximately 32 inches, the driver will see it and can manually push the 
arm to a locked position. When the latch is within the slot 102, the arm 
is approximately 32 inches from the body of the vehicle. Locking in the 
other slots positions the arm less than 32 inches by approximately 6 
inches per slot. If the failure occurs when the cylinder is less than 
approximately 32 inches from the body, the latch 110 will lock the 
carriage and thus the arm and if the extension cylinder assembly 32 is 
attempted to be actuated but doesn't, the operator will release the switch 
143 and the carriage will remain locked. Thus, when the vehicle is 
cornering or being driven on the highway, the arm will be locked and 
cannot be thrown outwardly by centrifugal or gravitation forces. Numerous 
alterations of the structure herein disclosed will suggest themselves to 
those skilled in the art. However, it is to be understood that the present 
disclosure relates to the preferred embodiment of the invention which is 
for purposes of illustration only and not to be construed as a limitation 
of the invention. All such modifications which do not depart from the 
spirit of the invention are intended to be included within the scope of 
the appended claims.