[0001] The present invention relates to a rucksack with a carrying frame, to be fitted on
the back of the wearer and comprising an upper frame section and a lower frame section,
which frame sections are connected to one another by a single hinge which can be put
under pressure.
[0002] A rucksack of this type is disclosed in US patent 4 214 685.
[0003] It has already long been recognised that the movement of the shoulders of a rucksack
wearer relative to the hips must be impeded as little as possible by wearing said
rucksack. After all, impeding said movement will give rise to earlier fatigue etc.
To this end all sorts of hinge constructions with which the conventional one-piece
frame can be constructed in several pieces have been proposed in the prior art.
[0004] In this context, in US patent 4 214 685 a hinge construction between the two frame
sections is proposed which makes it possible for the wearer to bend forwards and backwards.
This hinge also allows sideways movement by the wearer.
[0005] However, a construction of this type has a number of disadvantages. Firstly, it is
not possible to execute a torsional movement, i.e. the user is hampered in turning
his shoulders in a horizontal plane relative to the hips. It has been found that this
type of torsional movement takes place even when walking normally and this applies
more particularly in the case of complex movements, such as climbing. In this context
it is extremely important that the rucksack in question presents as little hindrance
as possible. Research by the Applicant has also shown that the three abovementioned
movements, i.e. forward bending movement, sideways movement and torsional movement,
are realised at different points in the spinal column and that, therefore, if a single
hinge is used, which is desirable on the grounds of simple design, an optimum position
for the location of said hinge will have to be sought. In this context it is important
that the hinge is capable of transmitting pressure forces because at least 60 % of
the weight of the rucksack is transferred to the hip region.
[0006] The object of the present invention is to overcome the disadvantages described above.
[0007] This object is achieved in the case of a device described above, in that the lower
limit of the upper frame section and the upper limit of the lower frame section, between
which the hinge is located, are chosen such that said limits are in the vicinity of
the lumbar region of the wearer, in that the hinge is a hinge acting in three dimensions
provided with means for driving said hinge into an initial position and in that separate
holders are fixed to the upper frame section and the lower frame section.
[0008] It has been found that by positioning the hinge point in the lumbar region of the
back of the wearer bending in particular can be carried out without hindrance.
[0009] By designing the hinge in such a way that said hinge operates in three dimensions,
it is now possible to allow the two separate frame sections to follow torsional movement
of the trunk. By designing the holders in two parts it is ensured that the holders
no longer stiffen the hinge. In order to prevent the weight, which is present in particular
in the upper holder, giving rise to tipping over, the hinge is of elastic design,
so that a restoring force to the original position is exerted. By this means, movement
by the user is further facilitated because the force required to return the spinal
column to the rest position will be lower.
[0010] It is pointed out that British patent 764 880 discloses a carrying frame comprising
two parts, the connection between the parts being realised by means of two springs
some distance apart. In this case it is necessary to pre-stress the construction before
attaching a rucksack. In addition, the spacing between the upper frame section and
the lower frame section will change, depending on the load in the rucksack. This spacing
is also dependent on the current position of the carrying frame. After all, in the
horizontal position the springs are not subject to the effect of gravity and in the
vertical position said springs will be somewhat compressed by gravity.
[0011] A hinge which has the desired characteristics and is particularly simple to produce
and very efficient comprises a rubber elastic connection. Rubber suspensions of this
type are generally known, in particular in the technology for insulating vibrating
components.
[0012] In US patent 4 214 685, described above, the shoulder straps are attached on the
one hand to the upper frame and on the other hand to the lower frame. It has been
found that for optimum effect the shoulder straps must be attached to the upper frame
section only. In this way, the hinge movement is affected as little as possible.
[0013] Although the upper frame section and the lower frame section are able to have all
of the shapes disclosed in the prior art, the effect of hinging, that is to say following
the movement of the back, is found to be realised in an optimum manner if the upper
frame section and/or the lower frame section are of U-shaped design.
[0014] Although the frame can be a so-called external frame, it is preferred according to
the invention to incorporate said frame in the rucksack as a so-called internal frame.
[0015] It can be desirable to make the separation between the two holders invisible. In
this case the provision of a cover between the separate holders is proposed.
[0016] For a standard frame the optimum length ratio between the upper frame section and
the lower frame section is found to be about 3:2. If, in particular, the upper frame
section is designed to be longer so that it extends to the vicinity of the wearer's
head, this ratio will, of course, have to be adjusted.
[0017] The invention is explained in more detail below with reference to the illustrative
embodiments shown in the drawing. In said drawing:
Fig. 1 shows, diagrammatically, a side view of a wearer provided with a first embodiment
of the rucksack according to the invention;
Fig. 2 shows a rear view of a second embodiment of the rucksack according to the invention;
and
Fig. 3 shows the carrying frame shown in Figs 1 and 2.
[0018] In Fig. 1 the rucksack according to the invention is indicated in its entirety by
1. Said rucksack comprises an upper holder 2 and a lower holder 3, which are separate
from one another. Both upper holder 2 and lower holder 3 each incorporate one frame
section, said frame sections being upper frame section 4 (see Fig. 3) and lower frame
section 5, respectively. It can been seen from Fig. 3 that said frame sections are
connected at 11 and 12 respectively by a rubber hinge 6. In the embodiment shown,
said hinge consists of a rubber section which is provided at the end with vulcanised-on
metal plates in which fixing means are incorporated for producing the connection to
the upper frame section and the lower frame section. It can be seen from Fig. 3 that
the upper frame section and the lower frame section are of U-shaped design, whilst
the length of the upper frame section is 3/5 of the total length of the carrying frame,
whereas the length of the lower frame section is 2/5 of the total length. It can be
seen from Figs 1 and 2 that the shoulder strap 7 is connected to the upper holder
2 at both the top end 9 and the bottom end 8. Lower holder 3 is connected directly
to hip strap 14.
[0019] Fig. 2 shows an embodiment which corresponds to that according to Fig. 1, except
that a bellows-shaped cover 13 is fitted between the upper holder 2 and the lower
holder 3.
[0020] By means of the carrying frame construction described above it is possible for the
upper frame section 4 and the lower frame section 5 to execute movement in three dimensions
with respect to one another. Consequently, carrying is less tiring for the wearer
and the wearer is less impeded in his movements, which is of importance especially
for climbing and the like. Despite the presence of hinge 6 it is possible to absorb
an appreciable pressure load to hip strap 14, so that the spinal column of the wearer
is spared as much as possible. By positioning in the vicinity of the lumbar region,
an optimum position is found for torsional, bending and left/right movement.
[0021] Although the invention is described above with reference to a preferred embodiment,
it must be understood that numerous modifications can be made thereto without going
beyond the scope of the present application. Thus, it is possible to replace the rubber
hinge acting in three dimensions which is shown in the application by any other hinge
which acts in three dimensions and has restoring properties.
1. Rucksack with a carrying frame, to be fitted on the back of the wearer (10) and comprising
an upper frame section (4) and a lower frame section (5), which frame sections are
connected to one another by a single hinge (6) which can be put under pressure, characterised in that the lower limit (11) of the upper frame section and the upper limit (12) of the lower
frame section, between which the hinge is located, are chosen such that said limits
are in the vicinity of the lumbar region of the wearer, in that the hinge (6) is a
hinge acting in three dimensions provided with means for driving said hinge into an
initial position and in that separate holders (2, 3) are fixed to the upper frame
section and the lower frame section.
2. Rucksack according to Claim 1, wherein the hinge comprises an elastic rubber connection.
3. Rucksack according to one of the preceding claims, wherein shoulder straps (7), the
two ends (8) of which engage on the upper frame section, are attached to the carrying
frame.
4. Rucksack according to one of the preceding claims, wherein the upper frame section
is of U-shaped design.
5. Rucksack according to one of the preceding claims, wherein the lower frame section
is of U-shaped design.
6. Rucksack according to one of the preceding claims, wherein the frame is a component
incorporated in the rucksack.
7. Rucksack according to one of the preceding claims, wherein a cover (13) is present
between the holders, which are separate from one another.
8. Rucksack according to one of the preceding claims, wherein the upper frame section
makes up about 3/5 and the lower frame section about 2/5 of the total length of the
frame.