This invention generally relates to a sliding door with a hermetic closure device which is intended to withstand internal pressure, and particularly to a sliding door including a sliding closure panel and a hermetic closure device comprising closure elements on at least two side edges and a lower edge of said closure panel to resist internal pressure.
Sliding doors generally comprise at least one closure panel supported in a sliding manner in a guide system which is fixed in relation to an opening in a vertical wall. In doors with a low level of demand regarding the hermetic closure, the guide is parallel to said vertical wall and provides a slight separation between the latter and the closure panel to prevent mutual friction during the longitudinal movements for opening and closing the panel. However, this slight separation remains when the panel is opposite to the opening of the door in a closed position and it is difficult to hermetically close.
For those doors requiring a greater level of tightness, such as cold chamber doors, sliding doors have been designed with a hermetic closure device comprising a guide system adapted for guiding a longitudinal movement of the closure panel parallel to said vertical wall between an open position, in which the panel allows the passage through the opening of the door, and a pre-closed position in which the panel is opposite to said opening, and then a transverse movement between said pre-closed position and a hermetically-closed position, in which the panel is applied against the vertical wall covering the opening and preferably compressing a sealing strip or gasket around the perimeter of the opening.
Spanish patent ES-A-265801 discloses a closure panel suspension device for a sealed sliding door of the type described above in which the force for compressing said sealing strip or gasket is provided by the weight of the closure panel in cooperation with gravity during a transition between the pre-closed and hermetically-closed positions.
U.S. Pat. No. 5,280,686 discloses a sealed sliding door or window arrangement in which the transverse movement for tightening the sealing strip occurs at the end of the longitudinal movement due to the effect of the force used to carry out said longitudinal movement in cooperation with final guide portions in the transverse direction between the pre-closed and hermetically-closed positions. A locking element can be actuated to immobilize the panel in the hermetic closure position. U.S. Pat. No. 6,479,072 discloses a sliding closure panel of similar features.
Spanish patent ES-A-382942 discloses a mechanically actuated sliding door for the hermetic closure of cold chambers provided with an arrangement of guides allowing the mentioned longitudinal and transverse movements of the panel and a hermetic closure device comprising a rack and pinion mechanism for moving bars parallel to the panel for the purpose of making wedge-shaped ends of said bars project on opposite sides of the panel and coupling said ends in fixed configurations arranged on the corresponding sides of the opening. The action of said wedge-shaped ends against the fixed configurations pushes the panel in the transverse direction between the pre-closed and hermetically-closed positions pressing against the seal around the opening.
U.S. Pat. No. 4,688,352 discloses an automatic sliding door for a cold chamber including longitudinal guide and actuation means parallel to the vertical wall where the opening is located and transverse guide and actuation means perpendicular to said vertical wall. The mentioned transverse guide means are incorporated in the elements for suspending the panel from the longitudinal guide means, therefore they move together with the panel, whereas the transverse movement means comprise four linear actuators arranged in fixed positions suitable for being opposite to the four corners of the panel. The actuation of said linear actuators pushes the panel in the transverse direction between the pre-closed and hermetically-closed positions pressing against the seal around the opening.
The background documents cited above refer to a level of tightness suitable for thermal insulation, i.e. for securing air under atmospheric pressure.
International patent application WO 03/096815, belonging to the same applicant, discloses a food cooking installation comprising a plurality of cooking tanks for housing the foods to be cooked and means for loading and unloading said foods through a side opening existing in each of the cooking tanks. The opening of each tank is provided with a sliding closure panel provided with a longitudinal movement between open and pre-closed positions similar to those described above, and a transverse movement between the pre-closed position and a closed position pressing against a sealing strip or gasket around the opening. The installation includes means for filling each tank with at least one cooking liquid and for subsequently emptying it. Given that the tanks have a considerable height, for example to allow the passage of a person through their opening, the liquid contained therein exerts significant hydrostatic pressure against an inner face of the closure panel. For this reason, each tank is provided with closure means for at least partly carrying out said transverse movement and pressing against and securing the panel against the vertical wall of the tank in a bearing hermetically-closed position, said closure means being able to withstand the mentioned pressure created inside the tank.
However, the mentioned international patent application WO 03/096815 of the same applicant does not develop said hermetic closure means for a sliding door able to withstand internal pressure.
This invention contributes to the mentioned development by providing a sliding door with a hermetic closure device which is intended to withstand internal pressure. The sliding door is of the type comprising at least one panel supported in a sliding manner in a guide system fixed in relation to an opening in a vertical wall of a closed structure having an inside and an outside. Said guide system is adapted for guiding the longitudinal movement of said panel parallel to said vertical wall between an open position in which the panel allows the passage through said opening, and a pre-closed position in which the panel is opposite to the opening, and a transverse movement between said pre-closed position and a bearing hermetically-closed position, in which the panel is applied against the vertical wall covering the opening and compressing a sealing strip around the perimeter of the opening. Closure means are incorporated for at least partly carrying out said transverse movement and for pressing against and securing the panel against the vertical wall in said bearing hermetically-closed position withstanding pressure created inside said closed structure. To that end, said closure means comprise at least one first closure element arranged to act on a front edge of the panel, at least one second closure element arranged to act on a rear edge of the panel and at least one third closure element arranged to act on a lower edge of the panel.
The terms “front edge” and “rear edge” of the panel are used throughout this specification to refer to the front and rear vertical edges of the panel in relation to the longitudinal movement thereof in a closure direction, respectively.
The closure means preferably comprise a plurality of first closure elements for acting on different areas of said front edge of the panel distributed along same, a plurality of second closure elements for acting on different areas of said rear edge of the panel distributed along same, and a plurality of third closure elements for acting on different areas of said lower edge of the panel distributed along same. With a suitable number of closure elements a substantially uniform pressure of the two side edges, the front and rear edges, and of the lower edge of the closure panel against the sealing strip is assured in the corresponding portions of the perimeter around the opening. The upper edge is also dragged by the side, front and rear edges of the panel against the sealing strip in the upper portion of the perimeter of the opening.
Since the hydrostatic pressure determines an increasing pressure gradient downwards, the greatest pressures are applied in the areas of the panel adjacent to the lower edge and to the lower portions of the side edges, whereas the pressures are minimal next to the upper edge of the panel. For this reason an embodiment of the sliding door of the invention described below does not envisage closure elements acting against the upper edge of the panel. However, in those cases in which the internal pressure is uniform on the entire panel, for example when it is exerted by a gas or vapor under pressure, the sliding door of the invention can incorporate closure elements acting on the upper edge of the panel in a manner similar to how the closure elements associated to the lower edge do.
The first, second and third closure elements are connected to respective first, second and third actuation mechanisms each including at least one cam integrally joined to a shaft actuated in rotation by an actuator, such as a fluid dynamic cylinder. However each of said first, second and third mechanisms has specific features aimed at adapting their closure elements to the particular positions they occupy in relation to the panel and taking into consideration the movements of the panel.
The foregoing and other features and advantages will be better understood from the following detailed description of an embodiment in reference to the attached drawings in which:
First in reference to
The mentioned guide system, including said upper guide rail 2, is of a known commercially available type and is adapted to guide a longitudinal movement of said panel 1, parallel to said vertical wall 4, between an open position (shown by means of dotted lines in
Depending on the type of guide system used most of the transverse movement of the panel is carried out by a force provided by the weight of the panel 1 in cooperation with gravity at the end of the longitudinal closure movement. However, this force is not enough to press against the sealing strip 5 or to secure the panel in the hermetically-closed position withstanding internal pressure created by a cooking or cooling liquid filling the inside of the tank 10. To that end the sliding door of this invention has closing means 6 which allow carrying out at least a last part of said transverse closure movement, pressing against the sealing strip 5 between the panel 1 and the vertical wall 4, and securing the panel 1 in this bearing hermetically-closed position, withstanding the pressure created inside said closed structure 10.
According to the embodiment shown, the mentioned closure means 6 comprise a plurality of first closure elements 71 distributed along a front edge 11 of the panel 1 to act on different areas thereof, a plurality of second closure elements 72 distributed along a rear edge 12 of the panel 1 to act on different areas thereof, and a plurality of third closure elements 73 distributed along a lower edge 13 of the panel 1 to act on different areas thereof. However, in other applications not shown the closure means 6 can comprise a single first closure element for the front edge 11, a second closure element for the rear edge 12 and a single third closure element for the lower edge 13 of the panel 1. Also if needed, for example should the internal pressure be created by a gas or vapor, the closure means 6 could include one or more fourth closure elements to act on an upper edge of the panel 1 with an operation that is similar to that described below for third closure elements 73 associated to the lower edge 13 of the panel 1.
The mentioned first closure elements 71, one of which is shown in cross-section in
In the embodiment shown, the first actuator 30 is a fluid dynamic cylinder (
The first shaft 31 is vertically supported in a rotational manner in a position fixed in relation to the vertical wall 4 by means of a plurality of first supports 21 fixed to a side wall 17 of the closed structure 10 by means of respective arms 24 which, when the panel 1 is in the pre-closed or closed position, are opposite to the front edge 11 of the panel. Therefore the mentioned arms 24 and supports 21 support the first shaft 31 in a position such that the first closure elements 71 associated thereto are opposite to an outer face of an area adjacent to the front edge 11 of the panel 1 when the panel 1 is in the pre-closed or closed position. Fixed at suitable heights on said outer face of an area adjacent to the front edge 11 of the panel 1 are blocks of resistant material providing the corresponding front surfaces 14 on which the outer surfaces 33 of the first closure elements 71 make contact.
The first cams 64 are integrally joined to said first shaft 31 in identical angular positions and at different heights corresponding to the positions of the mentioned blocks, such that the first closure elements 71 act at the same time that the first shaft 31 is rotated.
The mentioned second closure elements 72, however, are connected to a second actuation mechanism including a plurality of second cams 65 integrally joined to a second shaft 41 by means of, for example, respective second keys 68, as shown in
The mentioned second actuator 40 is, for example, a fluid dynamic cylinder having a body connected to the closed structure 10 and a rod 44 connected to a lever arm 45 fixed to the second shaft 41. This fluid dynamic cylinder 40 is controlled to rotate the second shaft 41 in both directions a predetermined angle that is enough to make the second closure elements 72 act.
As shown in
The mentioned elastic member 47 can adopt various shapes. In some cases, as in the embodiment shown in
The angular position in which the pulling arm 43 is fixed to the second shaft 41 is such that, in combination with said elastic means 47, it locks a first portion of the rotation of the second cam 65 in a first direction with the rotation of the gripping member 62 between a released position, shown in
When the second shaft 41 rotates in a second direction, the pulling arm 43 forces the rotation of the gripping member 62 in a second direction, opposite to the first one, against the force of the elastic means 47 until driving the gripping members 62 to the released position and allowing the reverse movement of the panel 1.
Said third closure elements 73, however, are connected to a third actuation mechanism including one or more third cams 66 integrally joined to a third shaft 51, for example, by means of corresponding third keys 69. This third shaft 51 is horizontally supported in a rotational manner in a position that is fixed in relation to the vertical wall 5 by means of a plurality of third supports 23 fixed to a lower part of the closed structure 10, as shown in
As is best shown in
Therefore, during a first portion of the rotation of the third shaft 51 in a first direction in a predetermined angle, the third cam 66 rotates an equal angle that is sufficient for the mentioned outer surface of the third cam 66 to slide on said inner surface 52 of the cylindrical ring 56, carrying out a movement of the gripping member 63, sliding in a supported manner on said lower support 53 between a released position in which the gripping member 63 does not interfere with the path of the panel 1 between its open and pre-closed positions, and an intermediate contact position in which the gripping member 63 is coupled to a projection 16 fixed on the lower edge 13 of the panel 1 when said panel is in the pre-closed position. During a second portion of rotation of the third shaft 51 in said first direction, the third cam 66 continues to rotate, carrying out the movement of gripping member 63 between said intermediate contact position and a final closed position in which said projection 16 has been dragged together with the rear edge 12 of the panel 1 to the bearing hermetically-closed position, as shown in
Note that so as to not interfere in the movement of the panel 1 it is enough for the gripping member 63 to be slightly separated from said projection 16 in the released position, a rotation of the gripping members 63 in relation to the shaft 51 not being necessary. For this reason the third closure elements 73 do not include pulling arms such as those shown in relation to the second closure elements 72. By means of a rotation of the third shaft 51 in a second direction opposite to the first one, the third cam 66 rotates so as to drive the gripping members 63 again to the released position and allow the reverse movement of the panel 1.
In relation to
Thus,
At the same time as the steps carried out by the first and second closure elements 71, 72 during the closure sequence described in relation to
Due to the movement of the front edge 11, rear edge 12 and lower edge 13 of the panel 1, the upper edge also moves, compressing the corresponding portion of the sealing strip 5 between the panel 1 and the vertical wall 4. If it is considered necessary to incorporate closure elements (not shown) to act on said upper edge of the panel, a fourth shaft would be assembled in a horizontal position actuated by a fourth actuator and fourth closure elements associated to cam mechanisms fixed to the fourth shaft similar to those described in relation to
To actuate said longitudinal movement of the panel 1 in the direction parallel to said vertical wall 4 between the open position and the pre-closed position or vice-versa, the sliding door may include in a well known manner at least one actuator (not shown), such as a fluid dynamic cylinder or an electric motor. Depending on the type of guide system used, the mentioned actuator may also actuate at least one part of said transverse movement between the pre-closed position and the bearing hermetically-closed position or vice-versa.
In reference to
The sliding door according to this invention described and illustrated up to this point is suitable for being incorporated in a food cooking installation, of the type described in the mentioned international patent application WO 03/096815. Such installation comprises a plurality of food cooking tanks arranged in an organized manner along at least one path. Each cooking tank is provided with a closed structure 10 having an inside and an outside, at least one opening 3 in a vertical wall 4 of said closed structure 10 through which foods to be cooked can be loaded and unloaded, and at least one sliding door for opening and closing said opening 3. The installation further has an automatic device for loading and unloading foods to be cooked from said tanks through their respective openings and along the mentioned path, and means for selectively filling and draining from each one of the tanks a cooking or cooling liquid or fluid.
The embodiments described and shown have a merely illustrative and non-limiting character, and a person skilled in the art may conceive modifications and variations without departing from the scope of the invention as it is defined in the attached claims. For example, it is possible to fix on each of the first, second and third shafts 31, 41, 51 a first, second and third cam 64, 65, 66 of great length, respectively, and several of the respective first, second and third closure elements 71, 72, 73 could be assembled on each of said cams.
This application is a U.S. National Phase application of PCT Application No. PCT/ES2004/000145, filed Mar. 31, 2004.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/ES04/00145 | 3/31/2004 | WO | 00 | 9/18/2007 |