[0001] The present invention concerns improvements in or relating to hinges, especially
but not exclusively hinges for stacking/nesting containers, for example bread trays.
[0002] The means for enabling a bread tray to be stacked on a similar bread tray often comprise
a flap or bail arm arranged along a pair of opposed walls of the tray and pivotal
from a position outside the top opening of the tray to a position across this top
opening. When the flaps or bail arms are swung clear of the tray a similar tray can
be nested therein whereas when they are swung over the tray a similar tray can be
stacked thereon. Trays of this nature are disclosed in our co-pending U.K. Patent
Application 8328387.
[0003] Where flaps are employed, especially when the trays are manufactured by a moulding
from plastics materials, the hinges connecting the flaps to the respective sides of
the tray are often difficult and expensive to manufacture. The specification of these
hinges is high in that they must be robust, efficient in their operation, relatively
tamper-proof and at the same time, relatively simple to manufacture and assemble.
[0004] According to the present invention there is provided a hinge comprising a pair of
leaves provided with projecting knuckles arranged in interleaved relationship, the
or each knuckle on a first leaf being provided with a recess in each end thereof and
the or each knuckle of a second leaf being provided with a protrusion at at least
one end thereof so that with a protrusion accommodated in the recess of an adjacent
knuckle one leaf is pivotable relative to the other, the knuckles of said first leaf
being provided also with slots leading from the outer surface thereof to said recesses
whereby a protrusion may be passed through a slot on interfitment of the leaves.
[0005] Preferably the said leaves and knuckles are-manufactured from plastics material by
injection moulding.
[0006] Preferably the recesses in the knuckles from the first leaf are cylindrical and extend
through said knuckles. The slot in each knuckle of the first leaf preferably has a
width less than the corresponding width of a protrusion whereby on deforming the knuckle
the protrusion may be passed through the slot to be accommodated in the recess. The
recesses may be frusto-conical rather than cylindrical.
[0007] Preferably there are at least three knuckles on the second leaf and the protrusions
from the inner knuckles of the second leaf are frusto-conical bosses, having their
maximum diameter at that part thereof adjacent the knuckle.
[0008] Preferably the outer knuckles of said second leaf have protrusions provided by pips
mounted in a recess in the inner end of said knuckle, the diameter of the recess being
substantially equal to the diameter of the recess in the knuckles of the first leaf.
The pin may be cylindrical and removable and is preferably slidably mounted in the
recesses of the outer faces of the end most knuckles of the first leaf and means are
provided, after interfitment of the first and second leaves for sliding said cylindrical
member into the recess in the end most knuckles of the second leaf. No slots are provided
in said knuckles which accommodate said slidable pin.
[0009] Preferably the leaves are formed integrally with the opposed sides and flaps of a
stackable/nestable container manufactured by injection moulding from a plastics material.
[0010] In this instance the first leaf is formed integrally with a side of the container
and the second leaf with a flap. Preferably the slots in the knuckles in the first
leaf is placed in the direction of the base of the container.
[0011] Preferably co-operating means are provided on the first and second leaves whereby
the flap may be interfitted with the side only when it is disposed at one angular
disposition relative to the side.
[0012] The present invention provides also a stackable/nestable container have a flap hinged
to each of two opposed sides by a hinge as set out in any one of the preceding nine
paragraphs.
[0013] An embodiment of the present invention will now be described by way of example only
with reference to the accompanying drawings in which:-
Fig. 1 shows a partial plan of a stackable/nestable container with the stacking flap
removed;
Figs. 2, 3, 4 and 5 show partial sectional elevations through the lines II-II, III-III,
IV-IV, and V-V respectively.
Fig. 6 shows a plan of a flap for the tray, the left hand side being shown from the
under side the right hand side from above;
Fig. 7 shows a view on the line VII - VII of Fig. 6 and
Fig. 8 shows diagrammatically the fitment of a flap to a container.
[0014] A stackable/nestable bread tray is manufactured by injection moulding from a plastics
material and comprises a reticular base 10, front and rear walls (only the front wall
12 of which is shown in Fig. 1) and side walls 14 and 16. Flaps are hinged to the
upper ends of the side walls 14, 16 and are pivotable from a position in which they
lie alongside the outer surface of the walls 14, 16 to a position in which they overlie
the top opening of the container. In the former position a similar container can be
nested within the container whereas in the latter position a similar container can
be stacked thereon. The hinges for pivotally attaching the flaps to the container
sides are moulded integrally with the sides and the flaps. The first hinge leaf is
moulded in with the side 14 and is provided with a plurality of spaced apart cylindrical
knuckles 18 projecting therefrom, the endmost knuckles 18a being inwardly spaced from
the front and rear of the tray. Circular cross-section recesses 20 extend inwardly
from the end circular faces 22 of the knuckles 18 and can either take the form of
a through passage as illustrated in Fig. 4 or a frusto conical recess as illustrated
in Fig. 2, the recess terminating in a central partition 24. A slot 26 is provided
on the underside of each knuckle and extends from the outer surface thereof to the
recess. The walls of the slot converge inwardly and the width of the slot varies in
accordance with the part of the passage 20 to which it leads.
[0015] The flap shown in Fig. 6 has the second leaf of the hinge formed therewith and is
provided with cylindrical cross-section knuckles 28 which are so dimensioned and spaced
apart that when the flap is presented to the top of the side of the tray the respective
knuckles interfit. The knuckles of the flap, with the exception of the end most knuckles
28a, are each provided with frusto-conical or cylindrical protrusions 30 extending
outwardly from their end faces 32, the end faces 32 of the end knuckles 28a being
each provided with cylindrical recesses 34.
[0016] It will be realised that if a flap is placed with its knuckles below the corresponding
knuckles of the first leaf formed at the top of the side of the tray and the flap
is pushed upwardly, owing to the resilience of the plastics material from which the
tray is made the knuckles 18 of the first leaf will deform outwardly to allow the
protrusions 30 from the knuckles 28 of the flap to pass through the slots 26 until
they are engaged in the cylindrical recesses 20. When they are so engaged the resilience
of the material of the knuckles 18 causes them to return to their original position
so that the hinge is locked in place.
[0017] To provide a first safety measure to prevent accidental or deliberate removal of
a flap, a movable cylindrical hinge pin (not shown) is provided in the recess of the
end-most knuckles 18a of the first leaf. After fitment of the flap this pin can be
slid outwardly of the recess such that it occupies the recess 34 formed in the end-most
knuckle 28a of the flap. This prevents the flap from being removed from the side of
the tray by pulling it such that the protrusions 30 are pulled through the slots 26.
[0018] A further safety measure is best seen in Fig. 8 and comprises angled surfaces 40,
42 provided at the ends of the first and second leaves. The angles of these surfaces
correspond at only one position of the flap relative to the side of the tray (that
is when it lies in the plane of arrow A) in which position the surfaces are parallel
to the central axis of the slots 26, that is the direction of insertion of the flap
on to the side. This provision means that the flaps can only be removed when they
occupy one angular disposition relative to the sides and not only does this provide
tamper-proof feature, but on carefully choosing the angle such that it is one which
is not normally occupied by the flap in most operational conditions, accidental removal
of the flap from the tray is prevented.
[0019] It will be realised that a hinge has been described above with reference to a bread
tray but it is equally applicable to any other components which have to be hinged
together or in fact may be provided as a hinge adapted for attachment to two components
which have to be hinged together.
[0020] Various modifications can be made without departing from the scope of the invention.
For example, the flap need not be moulded from plastics material, the protrusions
need not be moulded integrally therewith but could be pins press-fitted into recesses.
1. A hinge comprising a pair of leaves provided with projecting knuckles arranged
in interleaved relationship, characterised in that the or each knuckle (18) of the
first leaf is provided uith a recess (22) in each end thereof and the or each knuckle
(28) of the second leaf is provided with a protrusion (30) at at least one end thereof
so that with the protrusions accommodated in the recesses of adjacent knuckles one
leaf is pivotal relative to the other, and in that the knuckles (18) of said first
leaf are provided with slots (26) leading from their outer surfaces to their recesses
whereby a protrusion may be passed through a slot on interfitment of the leaves.
2. A hinge as claimed in claim 1, characterised in that the said leaves and knuckles
(18,28) are manufactured from plastics material by injection moulding, the recesses
(22) in the knuckles (18) of the first leaf are cylindrical or frusto-conical and
the slot (26) in each knuckle (18) of the first leaf has a uidth less than the width
of a protrusion whereby on deforming the knuckle the protrusion may be passed through
the slot to be accommodated in the recess.
3. A hinge as claimed in claim 1 or claim 2, characterised in that there are at least
three knuckles (28) on the second leaf and in that the protrusions (30) from the inner
knuckles (28) are frusto-conical bosses, having their maximum diameter at that part
thereof adjacent the knuckle.
4. A hinge as claimed in claim 3, characterised in that the outer knuckles (28a) of
the second leaf have protrusions provided by pins mounted in a recess (34) in the
inner end of the knuckle (28a), the diameter of the recess (34) being substantially
equal to that of a recess (22) in a knuckle (18) of the first leaf adjacent to said
outer knuckle (28a).
5. A hinge as claimed in claim 4, characterised in that the pin is slidably mounted
in the recess of the outer face of the endmost knuckle of the first leaf.
6. A hinge as claimed in any one of the preceding claims,characterised in that the
leaves are formed integrally uith the opposed sides and pivotal flaps of a stackable/nestable
container manufactured by injection moulding from a plastics material.
7. A hinge as claimed in claim 6, characterised in that the first leaf is formed integrally
with a side (14,16) of the container and the second leaf with a flap and the slots
(26) in the knuckles (18) in the first leaf face generally in the direction of the
base (10) of the container.
8. A hinge as claimed in claim 6 or claim 7, characterised in that co-operating means
(40,42) are provided on the first and second leaves whereby the flap may be interfitted
with the side (14,16) only when it is disposed at one angular disposition relative
to the side.
9. A atackable/nestable container including flaps pivotally mounted to two opposed
sides at the top thereof characterised in that the flaps are mounted on the sides
by hinges as claimed in any one of claims 1 to 5.