Note: Descriptions are shown in the official language in which they were submitted.
2038595
WASTE CON~TN~R LID ~YSTEM
Field of the Invention
The invention relates to commercial and indust-
rial waste containers or "dumpsters" designed for emptying
into a waste removal truck by mechanical means. More
particularly it relates to improvements in the lids for
dumpsters.
Background of the Invention
Waste from businesses and industries is gene-
rally stored in large, wheeled metal bins referred to as
"dumpsters" which are designed to be emptied mechanically
by specially equipped garbage trucks having hydraulically-
operated lifting arms or forks which engage, lift and tip
the dumpster. It is important that water be kept out of
such containers, since users pay for removal by weight. To
avoid becoming filled with rainwater, a lid must be pro-
vided for the dumpster which is hinged to permit filling
and emptying of the dumpster. Such lids are metal and are
generally formed in two parts due to the large weight of
such lids. Even so, such lids are difficult for a user to
lift and also leak some water into the container. The lids
also tend to become bent when dumping into a full garbage
truck, as the lid presses against the mound of trash. Such
bending adds to the leakage problem in the container.
It is also useful to be able to lock the dumps-
ter lid, to avoid unauthorized persons placing waste in thedumpster. It is preferable that the driver of the garbage
truck need not have a key for the lock, nor have to descend
from the truck in order to unlock the lid.
Various systems have been proposed for rendering
dumpster lids easier to open. For example Hodge United
States patents 3,989,162; 4,014,457; 4,098,429; 4,148,411
and Re. 30,890 disclose a lid system in which rollers or
sliders assist the initial partial opening of the lid,
while a pivot arm allows the lid to hang freely when
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dumping. In other variants of the Hodge design, stops on
the inner surface of the lid hold the lid in a partially
opened position. Such designs require counter-weights on
the lid, and rollers tend to malfunction under the rigor-
ous conditions under which dumpsters are used. UnitedStates patent no. 4,609,117 also discloses a lid assembly
in which a curved lid is assisted in partially opening by
counterweight springs, and which swings freely when in-
verted.
Summary of the Invention
The present invention provides a waste contain-
er and lid assembly comprising a lid having a pivot arm
which operates on a pivoting surface attached to the side
of the container and having a fulcrum. The pivot arm has
first, second and third pivot points on its lower surface
in order to move the pivot point as the centre of gravity
of the lid shifts during opening to keep the centre of
gravity approximately over the pivot point. The lid is
connected to the container by a two piece hinge which
swings free when the container is inverted. The lid is able
to slide forward to permit automatic unlocking.
Brief Description of the Drawings
In drawings which illustrate a preferred em-
bodiment of the invention:
Fig. 1 is a side elevational view of the inven-
tion in a closed position;
Fig. 2 is a front view of the invention in a
closed position;
Fig. 3 is a rear view of the invention in a
closed position;
Fig. 4A through 4D are partial side elevational
views of the pivot arm of the invention in successive
opening positions;
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Fig. 5A through 5D are partial side views of thelid hinge of the invention in the successive lid positions
illustrated in Fig. 4; and Fig. 6 illustrates the invention
in the inverted position for dumping.
Detailed Description of the Preferred Embodiment
With reference to Fig ! 1, a waste container 10
has wheels 11 (which are optional), an upper edge 12 and a
lid 14. Side 15 of the container 10 is shown, although both
sides are identical. Hollow rectangular pocket 16 is welded
to side 15 and receives the forks of a fork lift garbage
truck for lifting, inverting and emptying the container.
Lid 14 has two handles 18 attached to its front edge. Lid
14 is attached along its rear edge to the container 10 by
a two part hinge 20 consisting of a central hinge 28, upper
hinge 26, and lower hinge 30. Upper hinge 26 is fixed to
the container by welding at bands 27. Plates 22 pivot on
hinge 26 and are fixed to the central hinge 28. An elon-
gated plate 24 pivots on hinge 28 at its upper edge and on
hinge 30 at its lower edge. Hinge 30 is secured also to the
container 10.
Extending perpendicularly about 3 inches from
each side 15 of the container 10 are three metal plates 40,
42, 44. Plate 42 is substantially horizontal and has welded
across the midpoint of its upper surface, in a direction
perpendicular to the side 15 of the container, a cylindri-
cal metal dowel which acts as a fulcrum in a manner de-
scribed below. A substantially rectangular pivot arm 32,also about three inches deep is welded to each side of lid
14. A metal bar 48 is welded to its side to guide the pivot
arm on plates 40, 42, 44.
The bottom surface of pivot arm 32 consists of a
first pivot point 34, first flat surface 36, second pivot
point 37, second surface 38 and third pivot point 39. In
operation, as shown in Figure 4, when the lid is closed the
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weight of the lid rests on point 34. As the front of the
lid is raised, surface 36 rotates on fulcrum 46 until point
37 makes contact with plate 42. At that point the arm
pivots on point 37 and surface 36 is lifted off fulcrum 46.
As the lid opens further, surface 38 comes to rest on
surface 42, and the lid rests in that position with some
stability. Finally, as the lid continues to be opened, the
pivot arm pivots on point 39 until surface 49 of the pivot
arm rests against plate 40. In this way, as the centre of
gravity of the lid is shifted to the right in Figure 4, the
pivot point is also shifted to the right, so that the
centre of gravity is always approximately over the pivot
point, making the lid relatively easy to open while provid-
ing a series of stable resting places as the lid is opened.
The present invention thus permits the lid to be con-
structed of very heavy material, yet the lid remains
relatively easy to open and close.
With reference to Figure 5, the hinge of the
invention is formed of two plates which jack-knife to-
gether as the lid is opened completely. However, when thecontainer is inverted for dumping, as shown in Figure 6,
the lid will hang freely between the two ends 26 and 30 of
the hinge. This also permits the lid to move up or down or
laterally away from the container if it should encounter an
obstacle, such as a mound of garbage, in the process of
being dumped. When the container 10 is brought back to its
upright position, point 34 strikes plate 44 which, along
with bar 48, guides point 34 back into the position shown
in Figure 1.
When the lid is in the closed position shown in
Fig. 5A, there is the possibility of the lid moving for-
ward about 1.5 inches due to the position of extension 50
on which hinge 30 is mounted. Due to the weight of the lid,
however, an individual could not move it while in the
closed position. Thus a locking system can be provided in
which a clasp, for example, can be locked over a protru-
sion on the front edge of the container, preventing lif-
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ting of the lid, but which comes free when the dumpster is
lifted and tilted forward by the emptying truck. As shown
schematically in Figures 1 and 2, a hooked clasp 60 can be
provided which is hinged at 62 and has an opening for ring
64 which can accept a lock (not shown) to secure it in the
lower position. The clasp 60 thus can be removed only by
removing the lock or allowing the lid 14 to slide forward
enough that clasp 60 clears edge 12.
As will be apparent to those skilled in the art
in the light of the foregoing disclosure, many alterations
and modifications are possible in the practice of this
invention without departing from the spirit or scope
thereof. Accordingly, the scope of the invention is to be
construed in accordance with the substance defined by the
following claims.
