STRUCTURE COMPRISING VERTICAL SUPPORTS FOR HOLDING OF A HORI- ZONTAL UPPER PART
The invention relates to a construction for supporting at least one top part which is horizontal in the position of use of the construction, e.g. a plate or a similar element, and with one substantially vertical support with a base for bearing against and/or for attachment to a floor, which support is placed at the underside of the ends of the top part and has grasping means for securing the top part.
For a number of purposes a need arises for tables which may be connected at the edges and be supported at or near the joints by table legs so that a continuous table surface is formed.
A continuous table surface may be necessary when a party, a meeting or a conference with a great number of participants is to be staged.
DE laid-open publication nr. 1.554.214 describes a load- bearing construction of the above mentioned kind which comprises both tabletops and supports.
Each support consists of two vertical rods, which each at the bottom is fixedly connected to the middle of a horizontal foot piece and at the top is fixedly connected to the middle of a horizontal cross member which e.g. may be shaped as a girder with a L-shaped cross section. Each of the rods form together with the foot piece and the cross member an H which is placed on its side. The middle parts of the vertical rods are enve¬ loped in a rotatable way by vertical tube sections which are interconnected by a horizontal girder whereby the tube sections and the girder are extending in a common plane.
Each of the rods may be turned in such a way inside the tube sections that the longitudinal direction of their foot pieces
and the parallel cross members are turned 90° away from the plane determined by the tube sections and the girder.
Each tabletop carries on the underside joggled fittings with a vertical web, which at the upper and lower edges are connected to horizontal flanges pointing in opposite directions away from the web. The upper flange may be fastened to the table top by f. inst. screws.
Three such fittings are placed in a transverse row at each end of the table top with the upper flange of the middle fitting pointing in the opposite direction of the corresponding flanges of the two other fittings, so that the underside of the tabletop, the webs of the fittings and the two lower flanges of the fittings, which are pointing towards each other, produce a transverse channel in which the cross piece of a support may be inserted.
If supports are inserted in the described way into their corresponding transverse channels the supports will be connected removably to the table top with the longitudinal di¬ rection of the foot pieces transverse to the longitudinal di¬ rection of the tabletop.
In the case of long tabletops further rows of fittings may be provided between the above mentioned rows at the ends which further rows may"each receive a support.
Corresponding rows of fittings are placed at each end of the tabletop along the side edges so that cross pieces on the supports may be inserted into the lengthwise extending channels formed by the said fittings in such a way that the foot pieces extend parallel to the longitudinal direction of the tabletop.
If e.g. two or more tabletops are to be connected end-to-end foot pieces will extend along the side edges of the assembled
table parallel to the side edges of the table which foot pieces may in an annoying manner be in the way of the feet and legs of the persons seated at the table. Furthermore the fixation of the supports to the tabletop may to a certain de- gree be pliable so that the tables may wobble if they are ex¬ posed to forces acting upon their sides, even if these forces are not very strong.
The insertion of the cross pieces in the above mentioned channels will also cause some trouble as a tabletop preferably has to be placed on one side edge so that the underside of the tabletop will be easily accessible during the insertion. Al¬ though this may be troublesome in the case of a single tablet¬ op, obviously it will be practically impossible if a great number of tables are to be connected end-to-end as this would demand that all the tables after the mounting of the supports was to be turned into the position of use at the same time.
Neither does the known construction present an opportunity for the setting up and assembling of at least two rows of assembled tables which rows are placed at right angles to each other.
Such setting up and assembling is often required for con- ferences involving a a large number of participants who are seated on the outer side of tables arranged as a square or a rectangle leaving open space in the centre.
When the tables are not in use the fittings may represent a considerable disadvantage during storing as the fittings, if the tabletops are placed surface to surface, easily may damage the surfaces of the adjoining tabletops, and these gradually may become more and more damaged.
Furthermore, the attaching of the fittings represents a con¬ siderable amount of work and the known construction is there¬ fore unnecessarily expensive and not very competitive.
In the known construction the tabletop in itself constitutes the load-bearing element, and it has therefore to be dimen¬ sioned on the basis of the determined load to withstand the deflection caused by the load. As the insertion of the supports in the fittings may take place from the sides of the tabletop as well as from the end, it is not possible to pro¬ vide the tabletop with a side frame to enhance its load carry¬ ing capacity. Therefore the only possibility is to design the tabletop with a sufficient thickness to achieve the necessary load carrying capacity. The tabletop therefore becomes com¬ paratively heavy in relation to its useful area.
In the known construction the supports only serve to take up the vertical forces and do not present any possibility for re¬ inforcing the tabletop.
The object of the invention is to indicate a load-bearing con¬ struction of the said kind which construction is devoid of the above mentioned disadvantages.
This object will be achieved by a construction of the kind in¬ dicated in the introduction which construction is characteris¬ tic according to the invention in, that each support in at least the end pointing towards the other support has a first and a second arm which may rotate on vertical axes between a first position in which the arms extend along each other and parallel to the end of the support and the first arm is closest to the said end, and a second position in which they extend parallel to each other and substantially at right angles away from the end of the support; that the arms at their free ends respectively have a first and a second coupling means which are designed to obtain an interacting po¬ sition respectively with the second and the first coupling means on the opposite support by way of the turning of the arms; and that the grasping means are designed to grasp the ends of the top part in the interacting position.
In a support according to the invention which at least on one side has two arms which may occupy a first position in which both arms are parallel to the end of the support, a possibi- lity has been provided for storing a support in periods in which it is not in use and in a way which calls for the least possible requirements of space.
Furthermore, the arms may be turned from this first position on axes which in the position of use of the support are verti¬ cal. Hereby a vertical load on the arms of the support will act in the direction of the gudgeon and the produced moment may be counteracted by a suitable dimensioning of the gudgeons and the bearings for these on the arms so that it is not ne- cessary to fasten the arms.
Had the arms on the other hand been rotatable on a horizontal axis, locking and fastening means would have had to be pro¬ vided at the bearings of the arms, so that such means could have prevented an unintended turning of the arms under the load.
When the arms have been turned to the above mentioned second position, the first arm on one support may interact with the second arm on the second support so that the two supports will mutually brace each other during the erection of the con¬ struction, and this mutual bracing may be increased by the in¬ teracting of the other two arms when the supports and their arms form a square frame.
This mutual reinforcement is increased by the arms being pro¬ vided at their ends with coupling means which are able to strengthen the connection between the abutting ends of the arms.
In this way the so defined supports at the same time bring about the possibilities of a not very space demanding storage
and of a stable support for a horizontal top part which as such do not need any strength to resist sagging under load as the load exclusively will be absorbed by the arms of the supports which function in the same way as the frame of an or- dinary table.
As a result it is possible to use a thin inexpensive plate as a horizontal top part which does not need reinforcements of any kind and therefore during storage may be placed close to- gether with similar tabletops without any risk that they may damage each other.
When a support at each end has a first and a second arm it may be preferable as indicated in claim 2 that the arms are placed symmetrically about a vertical axis through the center of the support, as it is hereby avoided that the support has to be turned in a certain direction in relation to the other sup¬ ports. Also a freedom in the placing of the supports is achieved if several horizontal top parts are placed end-to- end.
When the coupling means on the arms of two supports are coupled together and are pushed as close together as possible the horizontal top part may also be secured by friction be- tween the ends of the top part and preferably vertical end surfaces of a plate on the top side of the support, cfr. claim 3.
Should this friction in some cases not be sufficiently large to prevent a horizontal top part from rocking, e.g. as a re¬ sult of the exertion of a vertical force on the top side of an edge of the top part, it is possible as indicated in claim 4 to provide the end surfaces of the plates with pegs which may interact with corresponding holes in the end of a top part.
The coupling means of the arms may also, to maintain a hori¬ zontal top part on two supports, be provided with locking
means which are able to tighten the arms towards each other as indicated in claim 5.
Such locking means may advantageously be designed in the way described in claims 6-8.
The load-bearing construction according to the invention will in the following be explained further with reference to a pre¬ ferred embodiment concerning a table, but it will be obvious that the top part may consist of a lot of other elements be¬ sides a tabletop. It may e.g. be part of a conveyor which is to be supported. In other cases the top part may consist of a number of oblong objects, such as plant trays in a nursery garden, which objects are placed transversely to the longitu- dinal direction of the arms when these are placed in their above mentioned second position. The explanation will be dis¬ closed with reference to the drawings, in which:
Figs, la-c show a support for a construction according to the invention, as seen respectively from the end, from the top and from the side, and with the arms shown in a first collapsed position,
fig. 2 is a top view of two of the supports shown in fig. 1, and with the arms shown in a second extended posi¬ tion, before a tabletop is placed on the arms,
fig. 3 shows abutting ends of a first and a second arm in the extended or interacting position shown in fig. 2 and as a section on the line III - III in fig. 4,
fig. 4 is a section on the line IV - IV in fig 3 showing the same ends,
fig. 5 shows the ends in a contracted locking position and as a section on the line V - V in fig. 6,
fig. 6 shows the ends as a section on the line VI - VI in fig. 5,
figs. 7-9 are sections respectively on the lines VII - VII, VIII - VIII and IX - IX in fig. 6,
figs. lOa-c are views respectively from the side, from above and from the end of a tabletop which may be placed on a construction according to the invention.
fig. 11 is a top view of an example of a table assembled from several supports and tabletops according to the invention,
fig. 12 shows a keyhole-shaped cut-out in the first arm, and
fig. 13 is a section of a clasping mechanism.
The support 1 for a load-bearing construction according to the invention shown in fig. 1 has a foot piece 2 which in the middle is provided with a vertical column or girder 3. A hori¬ zontal top part 4 is fastened to the top of the girder 3, so that the support 1, as viewed from the end, has a shape simi¬ lar to the cross section of an I-beam. Even if the foot piece 2 in fig. 1 is shown shorter than the top part 4 it may also be of the same length. The foot piece has in the longitudinal direction an extent which makes the support sufficiently stable to permit placing it in an upright position, and the top part has an extent which is slightly smaller than the width of an ordinary table.
Within the scope of the invention the foot piece may consist of an outer and an inner part of which the inner part may be inserted and hidden in the outer part during storage, but may, f. inst. against the force of a spring, be taken out and turned 90°, so that the two parts together form a cross for stabilization of the support.
A load-bearing construction according -to the invention com¬ prises at least two supports 1 to carry and support a tabletop 5, inasmuch as the number of supports and tabletops 5 has to be adapted, partly mutually so that the individual tabletop 5 may be supported at both ends, and partly according to the number of tabletops which are necessary to achieve the desired number of places around the load-bearing construction. For supporting the abutting ends of two tabletops 5 only one single support 1 is needed, and at each extension of the con¬ struction by an additional tabletop 5 it is sufficient to use only one additional support 1.
A tabletop 5 which is placed on the load-bearing construction is plane as well on the upper side as on the underside and without fittings of any kind, and it needs in the simplest em¬ bodiment only to consist of an untreated chipboard or plywood plate, but the tabletop may according to the circumstances al¬ so be painted or laquered.
As the tabletop 5 is plane both on the upper side and on the underside, and is not provided with fittings of any kind, it is very inexpensive to procure, and in storage together with other tabletops 5 it will not damage the surfaces of the other tabletops 5.
Each of the two supports 1, which as mentioned above are ne¬ cessary for supporting a tabletop 5, which f. inst. may form a detached table, has at least in the end pointing towards the opposite support 1 a first arm 6 and a second arm 7.
The first arm 6 and the second arm 7 are attached at the two sides of the support and are each as such rotatable on a gudgeon 12, 13 which in the position of use of the support 1 is vertical, so that the arms 6, 7 may be rotated 90° between a first position in which they extend parallel at the side of each other along the end of the support 1 with the first arm 6
closest to said end, and a second position in which they ex¬ tend parallel to each other and away from the end of the support.
The arms 6, 7 may be secured in their first position, f. inst. by parts of a spring-loaded clasp placed between the arms which parts may interact, or by the use of a permanent magnet in case the arms are made of a magnetic material.
Preferably each support 1 has arms 6, 7 on each end and in this case the arms 6, 7 are placed symmetrically about a ver¬ tical axis 49 through the center of the support in question.
The arms 6 and 7 have at their free ends 8, 9 respectively a first 10 and a second coupling means 11 which coupling means 11, 10 in the above mentioned second position may interact with the opposite coupling means 10, 11 so that the arms 6, 7 are mutually rigidly connected whereby they may bear against the underside ralong each edge of a tabletop 5 which is placed on their upper sides 14. This support is maintained at three places, i. e. at the bearings for the gudgeons 12, 13 and at the coupling means 11, while lists may possibly be placed on the upper sides of the arms 6, 7 ^ further support.
The coupling means 11 on the second arm 7 comprises a rein¬ forcing plate which surrounds the free end 9 on three sides so that the freely extending edges may guide the free end 8 of the first arm when the arms 6, 7 are brought into interaction. For the sake of clearness the reinforcing plate is shown only in figs, la, lb, 2 and 9 and is omitted in the other figures.
The suports 1 have at their upper side a plate 15 which has an extent corresponding to the width of a tabletop 5 and which in the longitudinal direction of the tabletop is limited by en surfaces 16 r 17.
The end surfaces 16, 17 constitute grasping means for holdin
the opposing ends 18, 19 of a tabletop 5 which is placed on the supports 1 when these arms 6, 7 are in the above mentioned second position.
Furthermore, the holding of the tabletops 5 by the end sur¬ faces 16, 17 may be enhanced by providing the end surfaces 16, 17 with short dowels 21 which may interact with corresponding holes 20 in the ends 18, 19 of the tabletop 5. The dowels 21 are shown only in fig. 2 of the drawings. Hereby it is possib- le to prevent rocking of the tabletop 5 in case a heavy object is placed on the tabletop outside the arms 6, 7.
Moreover, the plates 15 have a height corresponding to the thickness of a tabletop 5 so that the plates 15 and the table- top 5 in the assembled state may form a level and smooth upper surface without irregularities and projections.
To increase the friction between the end surfaces 16, 17 and the ends 18, 19 of the tabletops the coupling means 10, 11 may advantageously be provided with devices to pull the arms 6, 7 together in their longitudinal direction, when the arms are placed in the above mentioned second position so that from the interacting position they are brought into a locking posi¬ tion in which the end surfaces 16, 17 are clasping the ends 18, 19 of the tabletop 5.
These locking devices will be explained further with reference to figs. 3-9.
For reasons of strength the first arm 6 and the second arm 7 have a substantially U-shaped cross section as shown in figs. 7-9.
At a short distance from the free end 9 of the second arm 7 a circular cylindrical bolt 23 is secured to the inner surface 34 between the two branches 22 of the U, f. inst. by thread¬ ing, welding, gluing, riveting, or by some other known method,
which bolt has a shape with various diameters. As seen from the inner surface 34 the bolt has a resting part 24 with the greatest diameter, after that a short neck 25 with a con¬ siderably shorter diameter and finally a head 26 with a dia- meter between the diameters of the resting part 24 and the neck 25. In this way the circular cylindrical bolt takes the shape of a collar button.
The outermost free end 9 of the second arm 7 and the bolt 23 constitute the coupling means 11 of the second arm 7.
The first coupling means 10 of the first arm 6 has a more complicated shape.
Two cylindrical pins 28 are secured to the inside 35 of the first arm 6 and surrounded by the two branches 27 of the U, of which pins one is placed at a short distance from the free end 8 of the arm 6 and the other is placed at a greater distance. The pins 28 are secured to the inner surface 35 of the arm 6 in the same way as is used for the bolt 23. The free ends 29 are provided with a thread so that nuts 30 may be screwed unto the pins 28. For the sake of clearness the threads are not. shown in the drawings.
Furthermore, the pins 28 are each surrounded by a spacer bush¬ ing 31 which is surrounded by another bushing 32 which is shorter than the above mentioned bushing 31. The bushings 31, 32 may possibly consist of a single bushing which at its ra¬ dially outer side has a step which corresponds to the outward shape of the two bushings.
A guide plate 33 may by the aid of the bushings 31, 32 and the nuts 30 on the pins 28 be secured with its plane in a de¬ termined distance from the inner side 35 of the first arm 6.
A swivel pin 36 with a head 37 is placed between the pins 28 which swivel pin is accessible from the outer side 38 of the
arm 6 through a hole 39 in the arm 6. The head 37 may, as shown in fig. 7, be shaped as a bolt head so that the swivel pin 36 may be turned on its axis by means of a corresponding key, or it may be furnished with a slot for a screwdriver or with a cut-out for an umbraco key.
The swivel pin 36 is mounted rotatable in two places in the first arm 6 as there is a bearing bushing 40 which is secured to the inner side 35 and constitutes one bearing, and a bore 41 in the above mentioned guide plate 33 which constitutes the other bearing.
When the swivel pin 36 is placed in the two bearings 40, 41 it will be secured immoveably in its longitudinal direction by means of a locking means 42 which after the mounting will be secured against turning and displacement on the swivel pin 36. This connection may f. inst. be established by means of a locking pin (not shown), which is inserted transversely of the swivel pin 36 and the locking means 42.
The locking means 42 must for reasons of strength have a cer¬ tain extent or thickness in the direction of the axis of the swivel pin 36. The guide plate 33 is therefore bent back at the middle as shown clearly in figs. 4 and 6.
The coupling means 10 further comprises a locking bar 43 which like the arms 6, 7 has an U-shaped cross section, cfr. figs 8 and 9.
The locking bar 43 is supported slidably in a limited way in the longitudinal direction by means of two oblong cut-outs 44 which embrace the pins 28, so that the locking bar 43 is slidably mounted between the end of the spacer bushing 32 and the guide plate 33. Friction reducing materials may possibly be introduced, such as nylon disks on the pins 28 on each side of the locking bar 43, to reduce the friction between said parts.
The end of the locking bar 43, which is pointing towards the second arm 7, has a circular bore 45 with a diameter which is slightly larger than the diameter of the head 26 so that the bore 45 may slide over the head 26 of the circular, cylindri¬ cal bolt 23 on the second arm 7, whereby the locking bar 43 may bear against the resting part 24 in the space opposite the neck 25 and between the resting part 24 and the head 26.
The locking bar 43 has a further cut-out 46 between the cut¬ outs 44 and adapted to the distances between the pins 28 and the swivel pin 36. The shape of the cut-out 46 is apparent frem figs. 3 and 5 and it is accomodating the locking device 42 which has a long arm 47 and a short arm 48.
Contemplating figs. 3 and 5 it will be apparent that turning the locking device 42 clockwise from the interacting position shown in fig. 3 will displace the locking bar 43 in the di¬ rection towards the vertical gudgeon 12 of the arm 6 as the result of the cooperation between the long arm 47 of the lock¬ ing device 42 and the cut-out 46, and that a subsequent turn¬ ing of the device in the opposite direction will make the locking bar 43 move in the opposite direction into a locking position. Furthermore, the locking bar 43 is forced by a spring (not shown) in the direction of the second arm 7 so that the circular bore 45 extends so far out of the first arm 6 that it, depending on the position of the locking device 42, may clasp the circular, cylindrical bolt 23 on the second arm 7.
If the circular bore 45 of the locking bar 43 is moved to clasp the neck 25 of the bolt 23 on the second arm 7, the arms 6 and 7 will be pulled together in their longitudinal di¬ rection and thereby be locked together in the above mentioned locking position when the locking device is turned clockwise in fig. 3. The edges of the circular bore 45 will by this displacement of the locking bar 43 be inserted between the
head 26 and the resting part 24 so that the locking bar 43 will be fastened securely against displacement away from the resting part 24; the interaction and locking position.
Fig. 11 shows an example of a table assembled from several tabletops 5 and a corresponding number of supports 1.
Plate end pieces 50 are provided for the use together with a support 1 which is placed at the end of a tabletop 5 or a number of assembled tabletops 5, which plate end pieces may form the end of the assembled table and cover the unused arms 6, 7 which are pointing away from the tabletop 5 or row of tabletops. The plate end pieces 50 may f. inst. be rectangu¬ lar, or may have a free edge which is part of an ellipsis or an arc of a circle.
If tables are to be placed corner to corner with the longitu¬ dinal directions of the tabletops 5 at right angles to each other, the space between them may be filled out by an inter- mediate plate 51 with two straight edges of a length corres¬ ponding to the width of the adjoining tabletop 5 and at right angles to each other, while the free ends of the edges con¬ tinue into an arc of a circle with a. radius corresponding to the length of said edges.
In contrast to the tabletop 5 these plate end pieces 50 and intermediate plates 51 has to be provided with at least one fitting 52 on the underside so that it is possible to achieve a joining with a support 1 and/or the arms 6, 7.
The fitting 52 may have the shape of square sectioned tube which in a suitable way is secured along the edge of the plates 50, 51, which tube accomodates a catch 53 with an axis parallel to the plane of the plate 50, 51. The catch is pro- vided with a head 54, which may be shaped in the same way as the head 37 on the swivel pin 36, so that the catch 53 may be turned on its longitudinal axis by means of a suitable tool. A
disk 55 with two diametrically opposing branches 56 is connected to the opposite end of the catch 53.
The side of the second arm 7 has a keyhole-shaped cut-out 58 with an outline corresponding to the disk 55 and its two branches 56.
The inner side 34 of the arm 7 has around the cut-out 58 sur¬ faces which follow a helical course with a low pitch.
In the mounting of the plates 50, 51 they are placed on top of the arms 6, 7 while these are in their first position; where¬ after the disk 55 and its two branches are inserted through the cut-out 58 and in an as such known manner are turned 90° whereby the branches 56, by bearing against the above men¬ tioned helical surfaces, pull the catch 53 against the arm 7.