 |
Description  |
|
|
The present invention relates to a protecting device for transparencies
preferably intended for overhead projectors and pivotably mounted about a
swivel pin in the protecting device.
By overhead projection several associated transparencies are usually used
for visual communication work. There is often a demand for the possibility
of inserting different combinations of these transparencies in the window
field of the apparatus so as to produce a composite image. Furthermore
there is a demand for the possibility of stepwise building up or breaking
down a composite image. Sometimes problems arise in connection with filing
and especially during presentation of the transparencies since it can be
difficult to keep the slides in order and consequently there is a demand
for a system facilitating the handling of the transparencies in an easy
manner both during the filing and during the presentation thereof.
A number of various systems for filing and presenting transparencies are
known. The most simple systems thereof use loose transparencies filed in
separate folders, loose-leaf books or the like covers, from which said
transparencies must be removed before the presentation. At the
presentation, the transparencies are arranged one by one on the working
surface of the overhead projector, optionally in a permanent frame-like
structure which must be arranged on the working surface prior to the
presentation. The advantages of such a system are that it is very flexible
and that associated transparencies can be presented in any possible
combination. A suitable frame device renders it possible to obtain a
reasonably accurate arrangement of the transparencies during the
projection. This system is, however, encumbered with the draw-back that
each transparency is not particularly well protected and is easily turned
in an incorrect manner. In addition, it is easy to mix up the
transparencies during the presentation, and therefore particular auxiliary
means are necessary both during the presentation and at the filing thereof
as well as a good temporary filing place must be provided adjacent the
projector, especially when several sets of loose transparencies are being
presented.
Attempts have been made to overcome these draw-backs involved in using
loose transparencies by interconnecting said transparencies, e.g. by means
of spiral spines in such a manner that the transparencies can be inserted
in the image field of the projector by way of turning over said
transparencies, whereby a transparency is turned 180.degree. over one of
its edges. It is furthermore known to provide spirals and transparencies
with a particular unfoldable cover which can be fixed on a frame-like
apparatus, said apparatus having to be positioned on the projector prior
to the presentation. During the presentation, the transparencies are
turned over the spiral spine and inwards across a window in said
apparatus, from which they can be turned out again individually or
together. The most essential draw-backs arise in connection with the
highly limited possibilities of combining the individual transparencies,
which implies that the presentation can be rather difficult. In addition
the positioning of the transparencies on top of each other is too
inaccurate for many purposes owing to the necessary tolerance between the
spiral and the transparencies.
U.S. Pat. No. 3,279,109 discloses a protecting device of the above art
whereby the transparencies are arranged separately in covers which can be
turned inwards and outwards of the protecting device about a swivel pin in
said protecting device. This publication also discloses a projecting
device for the projection of transparencies on an overhead projector.
These devices do not, however, allow presentation of these transparencies
while they are still positioned in the protecting device, but require a
removal of said transparencies from the covers and from the protecting
device and a manual transfer thereof to the projecting device.
Subsequently, the transparencies are arranged on a swivel pin and may then
be projected by being turned over and away from the image field one by one
or in any desired combination and sequence. Beyond the fact that these
devices are rather complicated and involve a great risk of mistakes during
the movement of the transparencies from one device to another, they
provide no protection of the transparencies during the presentation.
Furthermore, this device requires a securing of the bottom layer to the
working surface of the overhead projector, e.g. by means of magnetic legs,
which presents particular demands to the bottom layer and to the working
surface of the overhead projector concerning shape and materials, and
which moreover locks the positioning of the image field during the
presentation to some degree.
The object of the present invention is to provide a protecting device of
the above type, which simultaneously is capable of serving as an easily
operatable presentation device for the transparencies in connection with
for instance an overhead projector, whereby the transparencies can be
presented in any possible combination and sequence, and which always
provides a good protection of the transparencies, and which is furthermore
detached and only rests on portions of the working surface of the overhead
projector in such a manner that it is easy to move the transparencies on
said working surface.
The protecting device according to the invention is characterised in that
it is formed as an unfoldable file comprising a bottom cover shaped as a
frame and provided with a transparent window as well as side members
secured to opposing rim parts of said bottom cover, said side members
carrying the transparencies turned out and a counterbalance thereto,
respectively, in the unfolded position of the file, and whereby the swivel
pin is mounted in the frame at one side thereof, preferably adjacent one
corner of the frame, in such a manner that it extends upwards
substantially perpendicular to the frame, and that the transparencies are
collated in a swivel cover so as to be turned out individually, said
swivel cover being pivotably mounted about the swivel pin, and whereby a
stopper for the transparencies is present which stops said transparencies
during their movement across the transparent window when they have reached
the correct presentation position on the transparent window.
As a result it is possible to store a set of associated transparencies as a
unit both during the filing and during the presentation thereof, and
furthermore the transparencies are well protected against dust, smudging
and the like damage. A further advantage of this device is that the
presentation can be carried out easily in an arbitrary, desired sequence
with a free possibility of combining the transparencies in the set. In
addition the presentation can be carried out without a particular,
separate frame or other loose auxiliary means, and without necessitating a
securing of the file onto the working surface since the unfolded device
remains in a position wherein its frame is planarly positioned above the
working surface irrespective of the nature and shape of said working
surface. At the same time it is easy to displace the device slightly on
the working surface during the presentation in such a manner that parts of
an image are outside the projecting field. Thus the protecting device
combines the advantages of using loose transparencies with the advantages
of a permanent binding of said transparencies without involving the
drawbacks known in connection with such systems.
According to an embodiment of the device according to the invention, the
side members secured to the bottom cover comprise a carrying part for the
transparencies with covers, which is secured at one rim portion of the
frame and an outer cover secured at the opposing rim portion of the frame,
said outer cover covering the frame with transparencies when the file is
closed. As a result the side members of the frame can be turned outwards
to opposite sides of the frame at the unfolding of the file in such a
manner that the carrying part to one side forms a carrying base for the
swivel cover with transparencies turned outwards from the projecting
field, while the cover turned outwards at the opposite side of the frame
can serve as a counterbalance transferring an oppositely directed moment
to the frame relative to the moment transferred to the frame by the swivel
cover with transparencies turned outwards. Furthermore, this swivel cover
may form a holder and a base for a booklet, a description of the figures,
pens and the like supporting material to be used during the presentation.
In addition the cover protects both the swivel cover with the
transparencies as well as the carrying part and the booklet etc. when the
file is folded.
According to an embodiment of the device according to the invention the
bottom cover and the side members are punched out in one piece from a
sheet material of moderately bendable and extremely ductile plastics, and
the carrying part and/or the opposing cover are shaped by bending portions
of the plate material along bending lines and by securing said portions
bent inwards to the bottom cover in such a manner that hollow spaces are
formed between the layers of the carrying part and/or between the layers
of the cover. This embodiment allows a rational and inexpensive
manufacture of the protecting device having a very low weight, whereby the
hollow spaces permit a resilient support of the transparencies turned
outwards and of the booklets etc. on the carrying part and the cover,
respectively.
It is according to the invention preferred that the inner layer of the
carrying part and/or the cover is shorter than their outer layers, and
that additional parallel bending lines are provided in both layers,
whereby the unfolded side members extend obliquely upwards from the bottom
cover and it is easy to fold the carrying part over the swivel cover with
transparencies turned inwards and to fold the cover over the carrying
part.
According to an embodiment of the device according to the invention the
bottom cover and the side members are punched out in one piece with
bending lines of a rather rigid sheet material, and the carrying part may
be folded and secured to the bottom cover in such a manner that a wedge is
formed, the spigot end of which faces the transparent window, and the
inclined surface of which forms a permanent bottom layer for a border of
the swivel cover turned outwards, and whereby the blunt end of the wedge
simultaneously forms a spine closing the side in question of the folded
file, and where an inner part of the cover is preferably folded and
secured to the bottom cover in such a manner that it forms a box-shaped
superstructure on the bottom cover next to the transparent window, said
superstructure being of a trapezoidal profile, the substantially vertical
side of which nearest to the transparent window is shorter than the
opposing substantially vertical side farthest from the transparent window
while the outermost part of the cover is connected to the innermost part
of said cover at the inner and upper rim of the superstructure in such a
manner that this part can turn about said rim, whereby when turned inwards
said part covers the transparencies in the swivel cover, the bottom cover,
and the carrying part, and whereby when turned outwards said part extends
obliquely upwards and outwards and is supported by the superstructure. As
a result, the cover and the swivel cover can be turned outwards to
opposite sides of the frame, where they are supported by solid structures
in planes inclining towards the frame. Furthermore, the torques of the
parts projecting beyond the bottom cover counterbalance each other. Such a
device can be manufactured in a simple and inexpensive manner, e.g. of
fibreboard in a conventional board processing machine.
The cover may advantageously comprise a closing flap at its free end, said
flap being adapted to be mounted and secured at the opposite side of the
frame or in the carrying part in the folded position of the file.
According to a preferred embodiment of the invention, the side members are
cast integral with the bottom cover of a rigid plastic material, while the
outer cover is cast of a plastic material of great ductility and by means
of a hinge connected to the side member opposite the carrying part of the
swivel cover and the transparencies turned outwards, said outer cover
furthermore being shaped as a cover with side rims, which when the file is
closed enclose the bottom side of the bottom cover and the carrying part.
In this manner an embodiment of the device is obtained which possesses a
high resistance to impact and a high wear-resistance and which
simultaneously closes tightly on all sides so that the transparency
contained therein is protected against damages, dust and moisture to a
maximum.
The carrying part comprises advantageously one or more wedge-shaped
brackets, the spigot end of which faces the transparent window and the
blunt end of which is secured to a rim extending substantially vertically
from the bottom cover. In this manner the consumption of materials for the
carrying part is minimized at the same time as the parts of the swivel
cover mounted on the brackets can be turned in an easy manner upwards so
as to rest on the upright rim when the swivel cover is turned away from
the frame.
The cover is hinged to the side member which advantageously is formed as a
trapezoidal box perforated at the rim of the surface inclining towards the
frame and positioned adjacent the transparent window, and the outer cover
may comprise a locking means with barbs secured to its hinge, said locking
means being pressed fixedly into the side member at the perforations
thereof.
The outer cover is advantageously provided with a small bead at the
outermost portions of the side rims thereof, which at closing of the file
surround the bottom cover and the carrying part. When the device is
closed, the bead grips about notches corresponding thereto along the
bottom sides of the bottom cover and the carrying part. Furthermore the
cover may be provided with a pipe abutting the bottom cover in a
substantially vertical direction when the file is closed, and on parts
opposing the pipe the carrying part may comprise grooves. In this manner
the outer cover is locked about the subject matter of the file when said
file is closed, but it may be easily disengaged by gripping by the thumb
of the right hand in the tube and by the remaining fingers in the grooves
so as to be turned outwards.
The transparent window is advantageously made of a transparent film of
plastics provided with flaps with barbs inserted in suitable slots in the
side members, said film being correctly positioned between the bottom
cover and the swivel cover by means of apertures punched out which fit
over low projections opposite the corners of the transparent opening and
along a low groove in the frame. In this manner the transparent window is
easily replaceable in case of smudging or damage, the flaps being released
from the slots by a hard pull so that the old film can be removed and
another film inserted.
According to a preferred embodiment of the protecting device, the swivel
pin is mounted at a corner of the frame in the side thereof where the
carrying part is positioned, and the transparencies and the swivel cover
are interconnected by means of a hollow rivet through swivel holes. The
hollow rivet may be pressed down on the swivel pin or it may be provided
with an internal thread corresponding to an external thread on the swivel
pin in such a manner that the rivet can be screwed off and on the pin. As
a result, the swivel cover and the transparencies are easily turned
between the position above the frame in the projecting field and a
position outside said projecting field, as well as the swivel cover with
the transparencies is secured by the swivel pin so as to be easily
replaceable by pulling or screwing off the hollow rivet. The connection
between the swivel cover and the transparencies is advantageously ensured
by means of a corbel or a disc on the free end of the rivet, or the hollow
rivet may be pressed or screwed downwards into a second hollow rivet,
whereby a bushing with corbels is formed on both sides of the swivel
cover. As a result, the removed swivel cover with transparencies can be
opened and closed so as to permit replacement of the transparencies.
According to a preferred embodiment of the device according to the
invention, a rectangular top cover is secured to the bottom cover and the
side members, said top cover extending vertially upwards from said bottom
cover. This rectangular top cover extends between the side members along
the rim of the bottom cover which is positioned adjacent the swivel pin
and further to such a height relative to the bottom cover that it
coresponds to the thickness of the closed device.
In this manner the subject matter of the file is protected against dust
from the top when it is vertically filed with said top cover turning
upwards, and the inner side of the top cover serves as a permanent, common
stopper for the transparencies when said transparencies are turned over
the transparent window.
According to a preferred embodiment of the device, bending lines are
provided in the top and bottom part of the swivel cover parallel to the
rims situated adjacent the projecting field upon the turning outwards.
These bending lines extend at such a distance from the rims that the
uppermost bending line is vertically positioned relative to the lowermost
bending line, and that borders of the swivel cover situated above the
bottom cover are pressed downwards by the swivel pin into planes
substantially parallel to the plane of the transparent window, while the
remaining, outermost portions of the swivel cover of the carrying part are
pressed upwards into an obtuse angle along the bending lines. When being
turned inwards the transparencies are pressed downwards into a horizontal
position above the transparent window at the border positioned between the
horizontal borders of the cover, and the hollow appearance of the
transparencies does not automatically cause a partial sliding of said
transparencies over the transparent field.
A stop bar is advantageously situated on the bottom side of the swivel
cover, and this stop bar falls over the upright rim of the carrying part
so as to rest against said rim when the swivel cover is completely turned
outwards. In this manner it is possible to prevent an undesired turning
back of the swivel cover turned outwards, while said stop can be easily
released by lifting the projecting portions of the swivel cover,
whereafter said portions can be turned downwards over the transparent
window.
A transparency according to the invention may be shaped as a transparent
folder, whereby the user may place his own transparencies in the device by
inserting them into such folders without separating the device.
According to an embodiment of the device according to the invention the
carrying part is a horizontal extension of the bottom cover and the swivel
cover is made of a rigid plastic material with a bending in an obtuse
angle so that the rim portions of the swivel cover facing the transparent
window are positioned in planes, when said swivel cover is turned
outwards. The planes are substantially parallel to the transparent window,
while the portions of the swivel cover projecting beyond the carrying part
incline upwards and outwards. The relation of the thickness of the
material to the flexibility may be chosen in such a manner that the
bending is straightened completely or partially at pressure from the cover
when the file is folded over the turned in swivel cover.
The device according to the invention may advantageously be made integrally
of lightweight materials such as fibreboard or plastics such a
polypropylene, or the bottom cover, the side member, the top cover, and
the swivel pin may be cast in one piece of a rigid material such as
polyethylene or milled in one piece of aluminium, while the outer cover
may be cast of a ductile material such as polypropylene, and the
transparent window may advantageously be punched out of scratch-resistant,
high-transparent plastics such as polycarbonate, and the swivel cover may
be cast or bent out of a slightly flexible plastics such as nylon or
polybutene, or it may be punched out and bent out of thick board or
fibreboard. These materials allow achievement of a construction having
favourable strength capacities and low weight as well as a suitable
flexibility in the portions where it is necessary.
The invention will be described below with reference to the accompanying
drawing, in which
FIG. 1 illustrates a folded protecting device according to the invention
with swivel cover and transparencies, whereby the transparencies are
turned outwards clockwise,
FIG. 2 illustrates an unfolded protecting device with a booklet,
FIG. 3 illustrates the protecting device of FIG. 2 with a turned out swivel
cover with transparencies ready for projection,
FIG. 4 illustrates the protecting device of FIG. 3 with a transparency
being turned inwards for projection and with an open booklet,
FIG. 5 is an exploded view of the protecting device of FIG. 2 with a
transparent window, a swivel cover with transparencies, and a swivel pin,
FIG. 6 is an exploded view of a swivel cover with a swivel rivet, a usual
transparency, and a transparency shaped as a folder, whereby the
transparency is to be turned outwards counterclockwise,
FIG. 7 illustrates a second embodiment of a protecting device according to
the invention, whereby the transparencies are to be turned outwards
clockwise,
FIG. 8 illustrates the protecting device of FIG. 7 with a turned out swivel
cover with transparencies,
FIG. 9 illustrates a third embodiment of a protecting device according to
the invention, whereby the transparencies are to be turned outwards
clockwise,
FIG. 10 illustates a sheet-shaped blank punched out for the manufacture of
the protecting device of FIG. 9,
FIG. 11 illustrates a fourth embodiment of a closed protecting device
according to the invention with inserted cuts, whereby the transparencies
are to be turned outwards counter-clockwise,
FIGS. 11A-B, 11C-D, 11E-F, and 11G-H, are cross-sectional views along lines
A-B, C-D, E-F and F-H of FIG. 11.
FIG. 12 is a top, perspective view of an unfolded protecting device with a
turned out swivel cover, whereby a transparency is partially turned
inwards and with an open booklet,
FIG. 13 is an exploded view of the protecting device of FIG. 11, and
FIG. 14 illustrates another embodiment of a swivel cover according to the
invention without transparencies and swivel rivets, whereby the
transparencies are turned outwards clockwise relative to a portion of the
bottom cover and the carrying part.
The protecting device illustrated in FIGS. 1-6 comprises a foldable file 1,
the bottom cover 2 and side members 6 and 7 of which are punched out in
one piece from a sheet material of plastics. The bottom cover 2 is shaped
as a rectangular frame 3 with a presentation opening 4. A transparent
window 5 secured to the bottom cover 2 is situated above the presentation
opening 4. The side members 6 and 7 are bent inwards along bending lines
13 and 14 and at their outermost ends 56, 57 they are secured to the
bottom cover 2. The side members including two layers and being bent
inwards form a carrying part 15 for the transparencies 8 with swivel cover
11 and a cover 16, respectively. When the file is folded the cover 16
protects the transparencies, and when the file is unfolded said cover
forms a base for a booklet 27. The inner layer 19, 20 of the carrying part
and the cover is shorter than the outer layer 21, 22 of said carrying part
and cover in such a manner that open hollow spaces 17, 18 are formed
between said layers when the file 1 is unfolded, cf. FIGS. 2-5. When
unfolded the carrying part 15 and the cover 16 are thus self-supporting
and more or less resiliently flexible depending on the material used.
Bending lines in the outer layers 23, 24 and in the inner layers 25, 26,
respectively, imply that the carrying part and the cover are easily
foldable to form a protecting file about the transparencies, cf. FIG. 1.
The transparencies 8 with swivel cover 11 are pivotably mounted about a
swivel pin 9 which is secured in a corner of the bottom cover 2 adjacent
the carrying part 15. The swivel pin comprises a stud 9b provided with a
head 9c. This stud is screwed into a hollow rivet 9a with an internal
thread and with a corbel 9d capable of locking the transparencies with the
swivel cover. FIG. 6 illustrates the building up of the swivel cover 11
with transparencies 8. The swivel cover comprises a bottom part 11a and a
top part 11b with a spine 11c. A stop bar 12 is secured to the bottom side
of the bottom part 11a. The transparencies 8 are provided with a gripping
register with holes 10a and notches 10b in opposing side rims of the
transparencies whereby the number of holes corresponds to the number of
remaining transparencies in the swivel cover, and whereby the holes are
situated opposite the notches of the remaining transparencies as well as
in a thirdside rim of the transparencies opposite the swivel pin. Thus a
number of notches 10c punched out in each transparency corresponds to the
number of remaining transparencies in the swivel cover in such a manner
that each transparency comprises a field not punched out where the
remaining transparencies are punched out. Corresponding holes 11d and
grooves are provided in the top part 11b opposite the holes 10a and the
notches 10b in the side rim farthest from the swivel pin. These holes 11d
and grooves oppose the notches 10c in the third side rim of the
transparencies, whereby these notches are detached. The file is
furthermore provided with a top part 28 secured to the bottom cover 2 and
extending between the carrying part 15 and the cover 16 along the rim of
the bottom cover nearest the swivel pin 9 and at a height from the bottom
cover corresponding to the thickness of the folded file. This top part 28
protects the transparencies against penetration of dust when the folded
file is vertically filed on a shelf with this rim turning upwards.
FIGS. 2-4 illustrate how the protecting device may be used as a projecting
device, e.g. on an overhead projector. The folded protecting device 1 is
situated with the bottom cover turning downwards on the working surface
and is opened by unfolding the carrying part 15 and the cover 16, cf. the
arrows A and B in FIG. 2. Subsequently, the swivel cover 11 with the
transparencies 8 is turned outwards over the carrying part 15, cf. the
arrow C in FIG. 3. Now the transparencies 8 may be turned inwards into the
image field about the swivel pin 9, cf. the arrows D and E in FIG. 4, by
means of the gripping register with the notches 10b and 10c and a stick 29
through the holes 10a,11d. during this movement, the top part 28 may
simultaneously serve as stopper for the transparencies 8 turned inwards
and thereby ensure that the transparencies turned inwards are accuately
positioned on top of each other. When turning each transparency 8 back
from a set of transparencies to the swivel cover 11, the stick 29 can be
moved to the hole 10a at the top part 28, whereby the transparencies not
to be turned back are retained by means of the stick 29. During the entire
presentation, the booklet 27 is situated freely on the inside of the cover
16 in such a manner that the text can be followed without difficulties
during the presentation. When the swivel cover is turned outwards over the
carrying part 15, said cover serves as a stop against the stop bar 12 in
such a manner that the swivel cover does not turn back over the
transparent window 5 in the image field if not desired.
FIG. 6 illustrates the embodiment of a swivel cover 11 for a single
transparency. This swivel cover is provided with a transparent folder in
which the transparency may be inserted as indicated at the arrow. The
swivel cover is furthermore provided with a gripping register with tabs
10.
FIGS. 7 and 8 illustrate a second embodiment of the protecting device,
whereby the carrying part 15 is shaped as a wedge with the spigot end
facing the transparent window and with a substantially vertical spine 30
being slightly resilient. The cover 16 includes one layer and is provided
with a closing flap 40 with snap fasteners 39 which at the closing of the
file may be pressed into snap fasteners 38 in the spine 30 of the wedge.
The top part 28 has been extended by a foldable connection 28a secured to
the cover and which when the file is open serves as a tie keeping the
cover 16 raised above the bottom cover. As indicated in FIG. 8, the swivel
cover is provided with a hinge fold 37 ensuring a correct positioning of
the turned out swivel cover and that the transparencies extend completely
planarly across the window when being turned inwards over said window.
FIG. 9 illustrates a third embodiment of the protecting device according to
the invention, said embodiment being manufactured by folding board. FIG.
10 illustrates a blank punched out for the manufacture of the embodiment
of FIG. 9. This embodiment is provided with a wedge-shaped carrying part
15 with a substantially vertical spine 30 and with a cover 16 and a top
part 28 extending therebetween and being secured to one side rim of the
bottom cover 2. The cover 16 comprises a flap 40 insertable in a slot 41
in the carrying part 15 when the file is being closed, said flap thereby
retaining the cover 16. A top part 28 extends between the carrying part 15
and the cover 16 secured to said carrying part and said cover as well as
to the side rim of the bottom cover 2 nearest the swivel pin 9. The
portion of the cover 16 nearest the bottom cover 2 is folded into a
box-shaped superstructure 31 of a trapezoidal profile and secured to the
bottom cover 2 by means of a bent securing part 35, whereby the outermost
portion 34 of the cover may turn about the inner and upper rim 36 of said
box-shaped superstructure. The inner, substantially vertical side portion
32 of the box-shaped superstructure 31 is slightly shorter than the outer,
substantially vertical side portion 33 of said superstructure, whereby the
outermost portion 34 of the open cover inclines slightly upwards away from
the presentation opening 4. This opening is coated with a transparent
window situated above the bottom cover 2 and the securing part 35 and the
innermost portion of the carrying part 15. As illustrated in FIG. 10, this
embodiment may be punched out in a continuous piece of board foldable
along the indicated folding lines and be maintained in the desired shape,
e.g. by means of rivets as indicated in FIG. 9.
The protecting device illustrated in FIGS. 11-13 comprises a bottom cover 2
cast integral with a box-shaped superstructure 31 and a carrying part 15.
The box-shaped superstructure 31 is at its inner, upper rim perforated by
holes 63 for the securing of the cover 16. The carrying part 15 is shaped
as two wedge-shaped brackets 15a and a rim portion 15b extending upwards
from the bottom and comprising grooves 15c allowing an opening of the
file. A top part 28 is also cast integral with the bottom cover 2 and
serves as a stopper when turning the transparencies 8 inwards. Slots 64a,
64b are provided in the box-shaped superstructure 31 and in the brackets
15a, said slots allowing a securing of the replaceable transparent window
5. This window is provided with suitable flaps 65a, 65b with barbs and
furthermore with holes 66 punched out and fitting over low projections 67
on the frame 3 opposite the corners thereof. The swivel cover 11 comprises
a bottom part 11a, a top part 11b, and a spine 11c, the two
first-mentioned being provided with bending lines 37. These bending lines
define borders from the remaining parts of the swivel cover 11, said
borders being horizontally situated above the transparent window 5. In
this position the swivel cover 11 inclines upwards from these borders. In
this manner the swivel rivet 9 may press the transparencies 8 downwards
into such a turned out position with a bending or hollow appearence
downwards that an undesired turning backwards of the transparencies 8 over
the transparent window 5 is avoided. The cover 16 is cast in the form of a
cover with a top rim portion 68, a side rim portion 69, and a bottom rim
portion 70, a hinge portion 71, and flaps 72 with locking pins 73 being
secured to said hinge portion. When assembling the device, these flaps
grip downwards about the holes 63 in the box-shaped superstructure 31. The
cover furthermore comprises a tube 74 which when closing the file abuts
the carrying part 15 and serves as a grip for the right thumb at the
opening of the cover. The side rim portion 69 of the cover 16 and the
portion of the bottom rim portion 70 nearest the side rim portion 69 are
provided with a small bead 75 which at closing of the file engages a notch
in the bottom cover 2 and the carrying part 15.
FIG. 14 illustrates a swivel cover 11 without transparencies. This cover is
turned outwards over a horizontal carrying part 15 and bent into an obtuse
angle long lines 76 parallel to the rim nearest the transparent window 5,
whereby borders of the top part 11b and bottom part 11a of the swivel
cover 11 are horizontally positioned above the carrying part 15 while the
remaining parts of the swivel cover 11 incline upwards and outwards from
these borders.
* * * * *
|
|
 |
|
 |
Description |
|
