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(11) | EP 1 215 358 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Automatic and controlled closing device for sliding doors and the like |
| (57) It is disclosed an automatic and controlled closing device for sliding doors and
the like comprising automatic drive means (6) for controlling the closing stroke of
a sliding door (2) brought to an open position, and friction braking means (7) for
the sliding door (2) adapted to slow down the closing stroke imposed to the door itself
by the automatic drive means (6). |
[0001] The present invention relates to an automatic and controlled closing device for sliding doors and the like, for refrigerated commercial stands and windows, in particular dedicated to the sale of drinks or ice-creams in self-service areas.
[0002] In such refrigerated stands automatic drive means is generally provided, to control the closing stroke of the sliding shutters or doors manually brought to an open position.
[0003] In the known art these automatic drive means can be embodied by balance weights connected to the doors by ropes or cables in such a manner that the opening stroke of each door causes lifting of the corresponding balance weight that, in turn, gives rise to the closing stroke of the door itself by its falling motion.
[0004] Since during the closing step the sliding door acquires a strong acceleration imparted to it by the balance weight and therefore tends to impinge at high speed on the side jamb against which it is designed to abut, for the purpose of avoiding damages to said jamb and other inconveniences such as crushing of fingers or hands that may accidentally be in its trajectory, the known art contemplates use of air means for braking the falling motion of the balance weight associated with each sliding door and adapted to prevent said door from reaching dangerous speeds.
[0005] Said air braking means substantially consists of a cylinder within which a plunger connected with the balance weight is slidable; said balance weight and its slide guide, as well as the cable for connection to the door are all housed in the jamb or side post of the refrigerated stand.
[0007] In fact, first of all, it is to be pointed out that the components of the above mentioned closing devices and in particular the balance weight mass, and the size and stroke of the air braking cylinders, are to be selected in advance in connection with the size and weight of the doors with which these devices are to be associated.
[0008] Practically, in the known art, it is therefore necessary that for each type of refrigerated stand a specific and labourious design study should be carried out for the purchase or manufacture of such components.
[0009] It addition, it should be recognized that housing of balance weights and air braking cylinders in side jambs of refrigerated stands obliges said jambs to have a rather important width, so that room is taken away from the space provided for holding the articles to be displayed.
[0010] Under this situation, the technical task underlying the present invention is to conceive a closing device for sliding doors capable of substantially obviating the mentioned drawbacks.
[0011] Within the scope of this technical task, it is an important object of the invention to conceive an automatic and controlled closing device which is substantially standardized and therefore offers an immediate and ready applicability to any type of sliding door.
[0012] Another important object of the invention is to conceive a device of limited bulkiness and insertable in the upper region of a stand at the inside of already existing structures, so as to maintain the side jambs to a reduced width for the benefit of the available inner space.
[0013] The technical task mentioned and the aims specified are substantially achieved by an automatic and controlled closing device for slidable doors and the like which is characterized in that it comprises friction braking means for said slidable door adapted to slow down the closing stroke imposed to the sliding door itself by said automatic drive means.
[0014] Description of a preferred but not exclusive embodiment of a device in accordance with the invention is now given hereinafter, with the aid of the accompanying drawings, in which:
- Fig. 1 is an elevation front view of a refrigerated stand provided with a sliding door to which the device in accordance with the invention is applied;
- Fig. 2 shows, to an enlarged scale, the portion of Fig. 1 adapted to highlight said closing device; and
- Fig. 3 shows a section taken along line III-III in Fig. 2.
[0015] With reference to the drawings, the device in accordance with the invention is generally identified by reference numeral 1.
[0016] It is applied to a slidable shutter or door 2 of a refrigerated stand 3 for example, which is provided with transverse guides 4 disposed at the upper and lower parts thereof and designed to direct the strokes of each door. The frame of the refrigerated stand 3 laterally has jambs or posts 5 against each of which the door 2 abuts in its closed position.
[0017] Practically, the stand or window intended for food conservation is made up of a frame defining a housing space and of one or more transparent sliding doors adapted to inhibit access to the housing space.
[0018] The closing device 1 comprises automatic drive means 6 for controlling the closing stroke of the door 2, which is advantageously defined by a return spring 13 disposed close to the transverse upper guide 4 and preferably housed within the latter.
[0019] The return spring 13 is adapted to store elastic energy during the door opening stroke, which energy is then given back during the closing stroke.
[0020] Obviously, any drive means, either of the elastic type or not, may be provided, as long as it is adapted to store energy during opening and give it back during the closing step of the door (balance weight or other means).
[0021] In an original manner, the device 1 also comprises friction braking means 7 adapted to slow down the closing stroke imposed to the sliding door 2 by the return spring 13.
[0022] The friction braking means 7 is formed of at least one sliding shoe 8 and one slide track 9 against which the former is slidingly in abutment. The slide track 9 is adapted to increase sliding friction with said shoe 8, so as to create at least one slowing-down stretch in the closing stroke of the sliding door 2 capable of avoiding high speeds to be reached by said door upon impact with jamb 5.
[0023] More specifically, the slide track 9 at said slowing-down stretch of the closing stroke of the door has a slight inclination with respect to the mutual sliding direction between the slide track itself and shoe 8, which is adapted to exert an increasingly growing pressure between the two last-mentioned elements and consequently cause an increase in said sliding friction.
[0024] Advantageously, the slide track 9 has a rectilinear extension and is applied to the inside of the upper transverse guide 4 within which the sliding door 2 is movable.
[0025] The sliding shoe 8 is, on the contrary, integral with the sliding door 2 through a support 10 to which it is steadily fastened.
[0026] During the closing step, the door 2 slides along the guides integrally carrying the sliding shoe or pad 8; the latter, as the door being closed moves forward, is increasingly more pressed against the track, thereby increasing friction between the two parts and consequently the braking force.
[0027] The breaking means 7 further comprises calibrating members 11 adapted to modulate the contact force with which shoe 8 abuts against the slide track 9 so that vicinity and sliding friction between the two last-mentioned elements, and consequently the closing speed of the door, can be adjusted, depending on requirements.
[0028] In more detail, the calibrating members 11 comprise an adjusting screw 12 disposed through an elongated hole 10a formed in support 10, the adjusting screw 10a enabling the support 10 to be locked to a varying distance from the slide track 9; as a result, the shoe 8 can be given greater or lesser pressure against the slide track 9 itself by positioning shoe 8, at the beginning, closer to or farther from track 9, respectively.
[0029] Preferably the slide track 9 comprises an end portion adapted to reduce the sliding friction with shoe 8 at a final stretch of the closing stroke of door 2, so as to ensure safe completion of the closing stroke of the door itself after said door has been conveniently slowed down, by enabling it to properly abut against jamb 5.
[0030] Practically said end portion of the slide track can be accomplished by reversing inclination of same and therefore reducing the shoe pressure against said track with respect to the remaining portion thereof which comes before in the closing stroke and has an increasingly growing friction.
[0031] However, from a technical point of view of more difficult accomplishment it will be possible to provide a reversal of positioning between shoe 8 and slide track 9 by associating the former with the upper transverse guide and the latter with door 2.
[0032] Further alternative embodiments could involve the presence of differently shaped tracks 9 to control more or less intense braking actions depending on positioning of door 2.
[0034] In fact, first of all, use of the return spring and the friction braking means of the type previously depicted enables the whole closing device to be confined within the upper transverse guide along which the sliding door is movable, thereby avoiding its being located laterally which would occupy a space that can be more conveniently utilized for holding articles for exhibition.
[0035] It is also to be pointed out that the device of the invention is made up of components of reduced costs that can be easily applied to all types of stands and to sliding doors of any and every size: the return spring practically can be the same for all applications and the slide track can be cut to size so that its length may adapt itself to the width of the sliding door.
1. An automatic and controlled closing device for sliding doors and the like comprising
automatic drive means (6) for controlling the closing stroke of a sliding door (2)
brought to an open position,
characterized in that it comprises friction braking means (7) for said sliding door (2) adapted to slow down the closing stroke imposed to the sliding door itself by said automatic drive means (6).
characterized in that it comprises friction braking means (7) for said sliding door (2) adapted to slow down the closing stroke imposed to the sliding door itself by said automatic drive means (6).
2. A device as claimed in claim 1, characterized in that said friction braking means (7) comprises at least one sliding shoe (8) and one slide
track (9) against which said shoe is slidably in abutment.
3. A device as claimed in claim 2, characterized in that said slide track is at least adapted to increase friction, preferably of the sliding
type, with said shoe so as to create at least one slowing-down stretch in said closing
stroke of the door (2).
4. A device as claimed in claim 2, characterized in that said slide track (9) at said slowing-down stretch of the closing stroke of the door
(2) has an inclination with respect to the mutual sliding direction between the slide
track itself and said shoe (9) which is adapted to exert an increasingly growing pressure
between the two last-mentioned elements during the closing stroke of the door (2).
5. A device as claimed in claim 2, characterized in that said sliding shoe (8) is integral with the sliding door (2) and in that said slide track (9) has a rectilinear extension and is applied to a transverse guide
(4) inside which the sliding door itself is movable.
6. A device as claimed in claim 2, characterized in that said braking means (7) comprises calibrating members (11) adapted to modulate the
contact force of said sliding shoe (8) against said slide track (9).
7. A device as claimed in claim 6, characterized in that said calibrating members comprise a support (10) for said sliding shoe and an adjusting
screw (12) adapted to lock said support to an adjustable distance from said slide
track (9).
8. A device as claimed in claim 3, characterized in that said slide track (9) comprises an end portion adapted to reduce the sliding friction
with said shoe (8) and corresponding to a final stretch of the closing stroke of the
door (2).
9. A device as claimed in claim 1, characterized in that said automatic drive means for controlling the closing stroke (6) of the sliding
door (2) is defined by at least one return spring adapted to store static energy during
its stroke for door opening.
10. A device as claimed in claim 9, characterized in that said return spring (13) is disposed close to a transverse guide (4) within which
said sliding door is movable.
11. A refrigerated stand particularly dedicated to the sale of drinks and ice-creams,
comprising a support frame defining a housing space and at least one sliding door
to enable or inhibit access to the housing space, characterized in that it further comprises an automatic and controlled closing device for the door according
to anyone of the preceding claims