EP0363575A1 - Pneumatic actuator with locking means in the end positions, especially for actuating smoke extractor flues - Google Patents

Abstract

In a pneumatic actuator with locking means in end positions, especially for actuating smoke extractor flues in smoke and heat extracting installations, a double-ended piston (9) can be displaced by a pressure medium in a mating cylinder with two cylinder chambers (9a, 9b). For the purpose of reliable locking of the end positions, on both sides outside the closed cylinder chambers (9a, 9b) and in each case adjacent to one of said cylinder chambers a locking piston (3 or 4) can in each case be displaced concentrically with the piston rod (10), which locking piston is connected to the adjacent cylinder chamber (9a or 9b) in a manner conducting pressure medium. Each locking piston (3 or 4) has a sleeve-like section (e.g. 4a) which in one locking position embraces radially guided balls (ii). In this arrangement, the balls partially engage in an annular groove (e.g. 10a) connected to the piston rod (10). The sleeve-like section releases the balls radially outwards when it is moved away axially from them. In one embodiment of the pneumatic actuator, this locking device can be supplemented as a double-stroke cylinder by means of an additional locking rod on the piston rod and a pressure-controlled reversing valve, which actuates an additional locking piston co-operating with the additional locking rod. <IMAGE>

Description

The invention relates to a compressed air cylinder with an end position lock, in particular for actuating smoke flaps in smoke and heat exhaust systems according to the preamble of claim 1.

Compressed air cylinders of this type with end position locking are used in smoke and heat extraction systems (abbreviated: SHEV systems) to open smoke and heat extraction flaps automatically or remotely in the event of a fire, so that smoke can escape, which would otherwise make rescue difficult or impossible, and thus a central access for the rescue is created. In addition, the build-up of heat build-up is to be prevented by opening the heat and smoke flaps. The compressed air cylinders used must meet high safety requirements. The relevant compressed air cylinders include end position locks, which have to apply locking forces that are a multiple of the normal force of the compressed air cylinder. In particular, the end position locking is intended to ensure extensive burglar resistance. The end position locking is carried out according to the state of the art by mechanically self-retaining elements.

In a known compressed air cylinder of the type mentioned at the outset, an end position lock is known in which a loaded pin or bolt or ball snaps into a groove. This constantly loaded locking element causes considerable abrasion, which limits the permissible number of switching operations. In addition, the relatively long design of such a lock disturbs the thus negatively affects the overall height of the compressed air cylinder, causes an increased space requirement and possibly limits the pivotability of the compressed air cylinder.

The present invention is therefore based on the object of developing a compressed air cylinder with end position locking of the type mentioned in such a way that the locking takes place in both end positions with as little wear as possible that a high number of operations is permitted. The compressed air cylinder with the end position lock should be compact, in particular have a small overall length.

This object is achieved by the formation of the compressed air cylinder with end position locking with the features specified in the characterizing part of claim 1.

The locking piston, which can be moved concentrically with the piston rod - and possibly with the locking rod aligned with the piston rod - enables a largely load-free locking of the radially movable balls, which partially engage in a rounded groove of the piston rod or locking rod. In the locked position, the balls are reliably held in the grooves by the sleeve-like section of the locking piston, which engages around the balls. If, on the other hand, the locking piston is pushed back by the balls, which occurs automatically when the compressed air cylinder is pressurized with the pressure medium, the balls are exposed on one of the two grooves, so that they move radially outwards from the grooves when the piston rod or the locking rod moves can slide. When the piston rod or the locking rod comes into an end position, the balls can easily be returned to the groove by the self-displaced locking piston. For this purpose, the end face of the locking piston is expediently provided with a chamfer. The movement of the bolt piston therefore takes place automatically when the associated pressure chamber of the counter-cylinder is acted upon by the pressure medium, since a locking pressure chamber on one side of the locking piston is in a pressure-conducting connection with one of the two cylinder chambers. If, on the other hand, the pressure in this cylinder chamber is reduced, the locking piston moves back automatically into its locked position, for which purpose the locking piston is particularly loaded by a compression spring. However, this compression spring does not act directly on the balls, which engage in the groove of the piston rod or locking rod, but only displaces the locking piston, which slides on the piston rod or locking rod with little wear and with its sleeve-like section over the balls.

The particular advantages of this compressed air cylinder with end position locking are that due to the practically load-free locking and unlocking, the locking elements are not subject to any significant wear, so that the materials from which these elements are made can largely be freely selected. So training from metals, for example brass, or plastic is possible. However, the permissible number of switching operations can be increased by using particularly resistant materials.

Another significant advantage is that the arrangement, in particular of the locking piston in the locking pressure chamber concentric with the piston rod or locking rod, the sleeve-like section of the locking piston enclosing the balls, makes the compressed air cylinder particularly compact, in particular short, without restricting its functionality is possible.

There is no problem with the compressed air cylinder to produce the features of the invention in a rational manner with different lengths and diameters. With short overall lengths, a larger usable room height is available for the assembly and operation of the compressed air cylinder even when installed vertically. In addition, the short design results in material savings in manufacture.

According to claim 2, the rollable balls, which are used for locking, are guided radially, for which purpose, in particular, a ball sleeve can be used.

Advantageously, however, radial guidance through the ball sleeve can be dispensed with if the balls lie against one another in the circumferential direction in the manner of a ring. In this case, a larger number of relatively small balls can be used, which are not separated from one another by sections of the ball sleeve. Due to the large number of small balls, e.g. 10 balls and more, a particularly high locking force can be achieved in an uncomplicated manner with even contact of the balls in the groove.

In the embodiment according to claim 4, in which the piston rod merges into the locking rods on one side of the piston, the piston rod can be made of a heavy-duty material, in particular V2A, while a lighter material, in particular an aluminum alloy, can be selected for the locking rod .

The section of each of the two locking pistons projecting from the compressed air cylinder according to claim 6 enables - with a corresponding profile - an auxiliary manual unlocking.

According to claim 7, an outer and an inner groove ring are expediently arranged in the locking piston, which is displaceable on the piston rod, which serve to seal the locking pressure chamber to the outside.

According to claim 8, the compressed air cylinder is advantageously closed at each end by a stop cover, which forms at least one spring receiving space and a stop for the locking piston each concentric to the piston rod or locking rod. This promotes the compact design of the air cylinder.

According to claim 9, the portion of the locking piston projecting from one of the stop covers has a bore in a manner known per se through which the piston rod is displaceably guided.

According to claim 10, the protruding from the other stopper section of the locking piston is closed. In this section, a support part is particularly advantageously displaceably mounted, which is aligned with the locking bar and pressed against its end face by a spring. With this space-savingly arranged support part it is achieved that, in the case in which the locking bar is pushed away from the balls, they cannot fall into the empty space otherwise created, but lie on the support part.

For a particularly compact design of the compressed air cylinder, one of the locking pistons, the support part and the stop cover with the spring receiving space at one end of the compressed air cylinder are arranged at least partially concentrically overlapping one another.

According to claim 13, the compressed air cylinder can have the two pressure medium connections for the two cylinder spaces - and associated bolt pressure spaces - in a plane aligned with one another at right angles to a main longitudinal direction of the compressed air cylinder on the cylinder head or else on the cylinder base. If, according to the further feature of claim 13, the cylinder head and the cylinder base are interchangeable, which includes, among other things, the same bores for the piston rod and the locking rod, depending on the configuration of the cylinder head and the cylinder base, a suspension of the compressed air cylinder can be used the pressure medium connections is mounted, attack in the upper part or in the lower part of the cylinder, which is designed as a double tube cylinder.

In the alternative according to claim 14, on the other hand, only one pressure medium connection is arranged on the cylinder head and one on the cylinder base, each of which faces a corresponding blind connection in one plane. With this single-tube cylinder, it is also possible to attach the suspension in the upper or lower part of the compressed air cylinder.

Particularly expedient materials for individual elements of the compressed air cylinder, which enable a light but reliable construction, are specified in claims 15 and 16.

Significant further developments of the compressed air cylinder consist in the fact that it, as a so-called double-stroke cylinder, can not only pass through one stroke, but apart from a smaller stroke, which corresponds, for example, to an angle of up to 90 °, a much larger stroke, corresponding to an angle of up to approx Deflection of the stroke into a pivoting movement, in particular for actuating the smoke flaps. With the smaller stroke, normal ventilation is set, while the larger stroke is required for the alarm state, for example in the event of a fire. The smaller stroke can also be understood as a partial stroke of the larger stroke. With the previous one Direction with compressed air cylinders that can travel through such a double stroke, disadvantages of the size, in particular the length and sealing problems with large surfaces to be sealed, which have to be shifted against each other. In addition, there has been a great deal of wear and tear on the end position lock and also a partial stroke lock

A compressed air cylinder designed as a double stroke cylinder according to a development of the invention according to claim 17, with which a short design of the lock and the cylinder itself is realized and which is also characterized by high wear resistance, has the features that coaxial to the piston rod and to this up to an additional locking rod is slidably provided on a stop on the piston rod, which limits a partial stroke of the piston rod and in this partial lifting position protrudes from one of the two locking pistons which were provided for the normal end position locking, that an external locking cylinder is arranged on the outside of this locking piston, in which a Additional locking piston is slidably mounted, which engages with a sleeve-like section in the partial stroke position balls which engage in an annular groove in the additional locking rod and are otherwise radially movable, and which releases the radially outwardly movable balls when it is released from d This is axially moved away, and that the additional locking piston is in communication with the closest adjacent cylinder space via a pressure-controlled reversing valve when a predetermined pressure is exceeded.

This double-stroke cylinder is characterized by a short design of the lock and the cylinder; the double-stroke cylinder need not be significantly longer than the basic version of the compressed air cylinder described above.

All locking devices of the piston rod are constructed on the same principle with little wear. The basic version of the compressed air cylinder described above can be expanded to a double stroke cylinder with little effort. External stop covers are used for the locking pistons, each of which has a hole. No stop cover is therefore designed to be closed. The piston rod, which is surrounded in this area by one of the two locking pistons, extends through one of the stop covers. The additional locking rod, which can be locked on the outside by an additional locking piston in the partial stroke position, is guided through the bore of the other stop cover and the other locking piston provided for the end position locking. The additional locking piston with the elements interacting with it, in particular the balls, which can slide into a groove in the additional locking rod, is constructed on the same principle as the locking piston for the end position locking. The pressure-controlled reversing valve automatically pushes the additional locking piston into a position that eliminates the partial stroke limitation when the controlling pressure of the medium, in particular the compressed air, exceeds a predetermined value for extending the piston rod. This compressed air is supplied to the additional locking piston or the adjacent locking pressure chamber from the adjacent locking pressure chamber of the rear or lower locking piston in a short way. The locking cylinder, in which the additional locking piston is slidably arranged, is preferably located directly on the rear or lower locking piston. Apart from an expedient design of the rear locking piston which is expedient for this purpose, the parts on the rear and front region of the double-stroke cylinder can be constructed identically and thus be exchangeable. This applies in particular to the interchangeability of the cylinder head with the cylinder base.

In particular, in the double-stroke cylinder, a guide rod is expediently slidably mounted in a bore in the piston rod, one end of which has a stop which limits the mutual displacement of the piston rod and the guide rod, and the other end of which is connected to the additional locking rod. Instead of the bore in a solid piston rod, the piston rod can also be designed as a tube. A very short overall length of the cylinder can be achieved due to the centric displaceability of the guide rod and the piston rod. The overall dimensions of the compressed air cylinder with end position locking are practically only increased by the dimensions of the partial stroke limitation and locking.

The double stroke cylinder can be designed both as a double tube cylinder and as a compressed air cylinder with only one tube.

Due to the design of the reversing valve, which actuates the additional locking piston according to claim 19, if there is no increased pressure for unlocking the additional locking piston, a leakage air connection from the additional locking piston or the adjacent locking pressure chamber to the outside is established, which prevents leakage of the additional locking piston and thus unintentional movement Unlocking prevented.

According to claim 20, the reversing valve includes a spring-loaded cup sleeve, which can establish a connection from a preset pressure between a pressure medium supply and a valve chamber, into which radial bores open. By changing the spring load, in particular setting a preload, the limit value of the air pressure can be determined, from which the pressure medium supply to the valve chamber is switched on and the double-stroke cylinder moves into the fully extended end position - alarm position.

For this purpose, the valve bore of the reversing valve is preferably conductively connected to the closest adjacent cylinder space pressure medium, and the radial bores lead to a locking pressure space in the outer locking cylinder.

The pressure-controlled reversing valve can be used simply and in a rational manner as a connecting valve, with which elements actuated by pressure medium, in particular at least one lifting cylinder, can only be actuated in a compressed air cylinder arrangement from a predetermined minimum pressure. For this purpose, the additional valve is inserted into the pressure medium line to the lifting cylinder. According to claim 22, the connection valve comprises a pressure-controlled reversing valve and, in the present variant, expediently a connection plate attached to the reversing valve, to which the pressure medium line - interrupted by the connecting valve - can be connected. The connecting bores are directly connected to the radial bores of the reversing valve via connecting bores. The reversing valve is constructed as claimed in claim 20. The same valve type can therefore be used for two different purposes, depending on how it is connected to the compressed air cylinder or a compressed air cylinder arrangement.

• Fig. 1 eine erste Ausführungsform des Druckluftzylinders, der als Einrohrzylinder ausgebildet ist, in einem Längsschnitt,
• Fig. 2 die dazugehörige Außenansicht,
• Fig. 3 eine Einzelheit zu dem Einrohrzylinder einer anderen Baugröße, nämlich einen Riegelkolben im Längsschnitt,
• Fig. 4 entsprechend Fig. 3 eine andere Einzelheit des Druck­luftzylinders, nämlich eine Kugelhülse im Längsschnitt,
• Fig. 5 als weitere Einzelheit ein Stützteil im Längsschnitt,
• Fig. 6 als weiteres Einzelelement einen Anschlagdeckel, ebenfalls im Längsschnitt,
• Fig. 7 eine zweite Ausführungsform des Druckluftzylinders, der als Doppelrohrzylinder ausgebildet ist, in einem Längsschnitt,
• Fig. 8 die zu Fig. 7 gehörende Außenansicht des Druckluft­zylinders in einer ersten Konfiguration,
• Fig. 9 eine Außenansicht des Druckluftzylinders nach Fig. 7 in einer anderen, zweiten Konfiguration,
• Fig. 10 die erste Ausführungsform des Druckluftzylinders nach Fig. 1, wobei der obere Teil der Fig. 10 in der unteren endverriegelten Stellung, d.h. der einge­fahrenen Stellung der Kolbenstange dargestellt ist und der untere Teil der Fig. 10 in der oberen endver­riegelten Stellung, d.h. der ausgefahrenen Stellung gezeigt ist,
• Fig. 11 die zweite Ausführungsform nach Fig. 7, wobei der obere Teil der Fig. 11 in der eingefahrenen Position der Kolbenstange dargestellt ist und der untere Teil der Fig. 11 in der ausgefahrenen Position der Kolben­stange,
• Fig. 12 eine dritte Ausführungsform des Druckluftzylinders, der hier als Doppelhubzylinder und Doppelrohrzylinder ausgebildet ist, wobei der untere Teil eine einge­ fahrene Stellung der Kolbenstange zeigt und der obere Teil eine voll ausgefahrene Stellung der Kolbenstange darstellt,
• Fig. 13 die dritte Ausführungsform in einer Teilhubstellung, wobei Zylinderkopf und Zylinderboden gegenüber Fig. 12 vertauscht sind,
• Fig. 14 eine vierte Ausführungsform des Druckluftzylinders, der hier als Doppelhubzylinder und Einrohrzylinder ausge­bildet ist, wobei der untere Teil und der obere Teil der Fig. 14 analog zur Fig. 12 zwei Endstellungen der Kolbenstange zeigen,
• Fig. 15 die vierte Ausführungsform in einer Teilhubstellung,
• Fig. 16 ein Zuschaltventil, bestehend aus einem druckgesteuer­ten Umschaltventil und einer Anschlußplatte in einer Schnittebene A-A (Figur 17) geschnitten,
• Fig. 17 das Zuschaltventil gemäß Fig. 16 mit einem Schnitt durch die Anschlußplatte in der Schnittebene B-B (Fig. 16) und
• Fig. 18 die Einfügung eines Zuschaltventils in schematisch dargestellten Ausführungsbeispiel einer Druckluft­zylinderanordnung mit einem Einhubzylinder und einem Doppelhubzylinder.

The invention is explained below with reference to a drawing with 18 figures. Show it:

• 1 shows a first embodiment of the compressed air cylinder, which is designed as a single-tube cylinder, in a longitudinal section,
• 2 the associated external view,
• 3 shows a detail of the single-tube cylinder of another size, namely a locking piston in longitudinal section,
• 4 corresponding to FIG. 3 another detail of the air cylinder, namely a ball sleeve in longitudinal section,
• 5 as a further detail, a support part in longitudinal section,
• 6 as a further individual element, a stop cover, also in longitudinal section,
• 7 shows a second embodiment of the compressed air cylinder, which is designed as a double tube cylinder, in a longitudinal section,
• 8 shows the external view of the compressed air cylinder belonging to FIG. 7 in a first configuration,
• 9 is an external view of the air cylinder of FIG. 7 in another, second configuration,
• Fig. 10 shows the first embodiment of the air cylinder according to Fig. 1, wherein the upper part of Fig. 10 is shown in the lower end locked position, ie the retracted position of the piston rod and the lower part of Fig. 10 in the upper end locked position, ie the extended position is shown
• 11 shows the second embodiment according to FIG. 7, the upper part of FIG. 11 being shown in the retracted position of the piston rod and the lower part of FIG. 11 in the extended position of the piston rod,
• Fig. 12 shows a third embodiment of the compressed air cylinder, which is designed here as a double-stroke cylinder and a double-tube cylinder, the lower part being a shows the driven position of the piston rod and the upper part represents a fully extended position of the piston rod,
• 13 shows the third embodiment in a partial stroke position, the cylinder head and cylinder base being interchanged with respect to FIG. 12,
• 14 shows a fourth embodiment of the compressed air cylinder, which is designed here as a double-stroke cylinder and a single-tube cylinder, the lower part and the upper part of FIG. 14 showing two end positions of the piston rod analogously to FIG. 12,
• 15 shows the fourth embodiment in a partial stroke position,
• 16 a cut-in valve, consisting of a pressure-controlled changeover valve and a connecting plate, cut in a sectional plane AA (FIG. 17),
• FIG. 17 shows the connecting valve according to FIG. 16 with a section through the connection plate in the section plane BB (FIG. 16) and
• 18 shows the insertion of a connecting valve in a schematically illustrated exemplary embodiment of a compressed air cylinder arrangement with a single-stroke cylinder and a double-stroke cylinder.

In Fig. 1, a compressed air cylinder with end position locking is shown, as it can be designed for example with diameters of 80 mm (Fig. 1 and 2) or 50 mm (Fig. 3 - 6). The diameter specifications are those of the piston 12. The compressed air cylinder essentially consists of a cylinder head 1 and a cylinder base 2, which are connected to one another via a cylinder tube 9. The cylinder head, the cylinder base and the cylinder tube enclose two cylinder spaces 9a and 9b, which are separated from one another by the double-sided piston 12. The piston 12 is fixed between a locking rod 7, which is also referred to as a locking bolt, and a piston rod 10.

It is noted that the longitudinal extent of the cylinder spaces 9a and 9b is greater than that shown in Fig. 1, so that the piston 12 can move about the stroke therein until it abuts one of the stops which through the end faces 1a and 2a of the cylinder head and the cylinder bottom are formed. The locking rod 7 and the piston rod 10 are both shown in the locked position in FIG. 1, although in each case only one locking is actually locking in one of the two possible end positions of the piston.

For locking in one of the end positions, the locking rod 7 and the piston rod 10 are each provided with a groove 7a and 10a, respectively, which is formed with a radius of curvature which corresponds to the radius of steel balls 11 which are used for locking in the grooves 7a, 10a.

The formation of ball sleeves 6a and 6b, which each hold four balls 11 radially displaceable and rotatable, but not axially displaceable, can be seen in detail in FIG. 4. The ball sleeve essentially forms a ring which has four bores offset along the circumference by 90 °, of which the bores 19-21 can be seen.

The ball sleeves and the locking elements interacting with them are each located in a bolt pressure chamber 22 or 23, which is enclosed by a jacket section of the cylinder head 1 or the cylinder base 2. In the jacket section, a locking piston 3 or 4 is guided displaceably concentrically to the piston rod 10 or the locking rod 7. The shape of the locking piston 4 is shown in detail in FIG. 3. Here are recognizable stepped cylindrical cavities 24, 25 for receiving the ball sleeve with the balls and a support part 8 in Fig. 1. The support part 8 is also in the main longitudinal direction, which by a broken line 26 is indicated, displaceable and is pressed by an indicated spring 18 against the end face of the locking bar. For the shaping of the locking piston 4, a groove 13a in FIG. 3 is also to be mentioned, which serves to receive a grooving ring 13. The opposite rear end of the locking piston has a smaller recess 13b to which a tool for manual displacement of the locking piston can be attached in special cases.

The locking piston 4, which is the rear or lower locking piston of the compressed air cylinder, is displaceably guided by a rear stop cover 5. The shape of the stop cover is shown in detail in Fig. 6. It has a bore 5a for slidably guiding the rear locking piston 4 and a support surface 5b on which a spring 17 indicated in FIG. 1 can be supported, which pushes the rear locking piston in the direction of the ball sleeve 6a and the balls 11.

The locking device shown in the left part of Figure 1 for locking the end position with a front or outer locking piston 3, which is also guided through a stop cover 5, corresponds essentially Lichen the locking device described above with the rear or lower locking piston 4, with the following exceptions: The locking piston 3 is not closed to the outside and does not form a space for receiving a support part, but it has a through bore 3a through which the piston rod 10 to the front protrudes. A sealing ring 14 and a scraper 15 are used to seal the locking pressure chamber 22 from the surroundings of the compressed air cylinder, adjacent to the bore 3a. A spring, which is only indicated, and which presses the front locking piston 3 in the direction of the ball sleeve 6b and the balls 11, is designated by 17 .

Pairs of blind holes 27, 28 in the cylinder head or 29, 30 in the cylinder base, which are arranged in one plane, serve to supply the compressed air actuating the compressed air cylinder and to optionally suspend the compressed air cylinder. The blind hole 27 is connected via channels 31, 32 to the cylinder chamber 9a and the bolt pressure chamber 22; the blind hole 30 is connected via channels 34, 35 to the cylinder space 9b and the bolt pressure space 23.

To explain the mode of operation it is assumed that the piston rod 10 is in the lower end-locked position, in which the piston 12 rests on the end face 2a and the end locking is effective by the balls 11 engaging in the groove 7a. Deviating from the situation shown in a simplified manner in FIG. 1, in this state the rounded groove 10a in the piston rod is located on the right outside of the balls 11 in the ball sleeve 6b. If the compressed air cylinder is now to be actuated, the blind hole 30 is pressurized with compressed air, which presses the piston 12 to the left outside. At the same time, the locking piston 4 is pressed to the right or back by the compressed air flowing into the locking pressure chamber 23, so that the balls 11 in the ball sleeve 6a are no longer retained in the position shown by a sleeve-like section 4a, but are moved radially outward under the influence of the locking rod 7 moved to the left. So that the balls 11 do not fall into the space left by the locking bar 7 when the locking bar moves away from the balls, the support part 8 is automatically pushed by the compression spring 18 engaging in its spring space 8a. The forward movement of the piston rod continues until the piston 12 abuts the end face 1a of the cylinder head 1, the balls 11 in the ball sleeve 6b being pushed into the groove 10a in the piston rod, as shown in the drawing. The end locking is effective because the balls 11, when the piston rod is loaded to the right, cannot move back radially outwards from the groove 10a, but remain in the position shown by a sleeve-like section 3b of the locking piston, in which they hold a multiple of the actuating force of the piston. If the compressed air cylinder is to be unlocked in the event of a failure of the compressed air supply, this is possible by pulling the locking piston 3 forward or outward, analogously to pulling out the locking piston 4 in the other end position by engagement of a tool in its recess 13b.

In FIG. 10, the two end positions of the piston 12 or the piston rod 10 discussed above in connection with FIG. 1 are illustrated more clearly. The upper part of the drawing, located above the main longitudinal axis 26, shows the piston and the piston rod in the lower end-locked position, which corresponds to the retracted position of the piston rod. It can be seen how the piston 12 bears against the end face 2a of the cylinder base. The end lock of the pistons shown on the right in the drawing rod is effective because the balls 11 are lowered into the groove 7a. The left end lock, however, is free, since the locking piston 3 is retracted so far that the balls 11 in the ball sleeve 6b are pushed radially outwards, where they can roll on the jacket of the piston rod 10.

The lower part of FIG. 10, however, shows the fully extended end position of the piston rod 10. The stroke into this extended position is only possible when the locking piston 4 is pushed to the right outside by the compressed air flowing into the blind hole 30, so that the balls 11 can roll freely out of the groove 7a, the balls moving radially outwards. Under the action of the compressed air, the piston 12 is then pressed up to the end face 1 a of the cylinder head 1. In this position, the balls 11 are lowered into the groove 10a in the piston rod under the action of the spring-loaded locking piston 3. This spring is not shown in Fig. 10; also no corresponding spring on the locking piston 4.

The embodiment of the compressed air cylinder according to FIGS. 7-9 as a double tube cylinder differs from that according to the figures discussed above, in particular FIGS. 1 and 2, essentially in that here only one cylinder head 41 with aligned blind holes 61, 62 lying in one plane is equipped, each of which is used optionally for the supply of compressed air and which are both used together to suspend the compressed air cylinder. In addition, the cylinder head 41 and a cylinder base 42 are mutually interchangeable, so that the suspension can optionally be carried out on the upper section of the compressed air cylinder, see FIG. 8, or on its lower section according to FIG. 9, depending on where the cylinder head 41 is attached is. It should be noted here that the representations of FIGS. 8 and 9 are rotated by 90 ° about the main longitudinal axis 26 compared to that in FIG. 7.

To explain FIG. 7, it is pointed out that the compressed air supply from the blind hole 61 to a first cylinder space 63 takes place via a channel 64 and play (not shown) on a piston rod 51. The compressed air supply to the bolt pressure chamber 45 also takes place through the play of the piston rod 51. The compressed air-conducting connection between the blind hole 62 and a bolt pressure chamber 46 at the right or lower end of the compressed air cylinder takes place via channels 47, 48 and a space between a cylinder tube 49 and a protective tube 50, which connect the cylinder head and the cylinder base with each other. A second cylinder chamber 65 is in turn fed with compressed air via a play of a locking bar 52. Depending on which of the blind holes 61, 62 is pressurized with compressed air, a piston 53 is moved forwards or upwards or backwards or downwards while simultaneously releasing the end lock on a rear locking piston 44 or on a front locking piston 43.

In Fig. 11, the extended position of the piston rod 51 in the upper part, ie above the main longitudinal axis 66 on the one hand and in the lower part of the same figure, the extended position of the piston rod are shown. In the retracted position, the balls, which are not designated, engage in the right locking piston 44 in a groove in the locking rod 52. The balls in the region of the left locking piston 43, on the other hand, are pressed outward onto the circumference of the piston rod 51. Conversely, in the fully extended, lower position of the piston rod 52, the balls in the region of the locking piston 43, which is pressed over the balls, snap into a groove in the piston rod, while the groove on the right in the locking rod 52 moves radially from the outside pressed balls is free in the area of the locking piston 44 pushed to the right outside.

The embodiment according to FIGS. 7-9 and 11 is intended in particular for smaller diameters of, for example, 35 mm of the piston.

While the embodiments of the compressed air cylinder described above represent single-stroke cylinders in which a single stroke is characterized by two defined end positions in which the piston rod is locked, the following embodiments relate to double-stroke cylinders. In the case of the double-stroke cylinders, the piston rod can be moved by a relatively large stroke and locked in its end positions, but also by a more defined smaller stroke in that the piston rod is held by the pressure present.

Specifically, the embodiment of a double-stroke cylinder according to FIGS. 12 and 13 corresponds to the two-tube cylinder form according to FIG. 7, so that corresponding parts in FIGS. 7, 12 and 13 are provided with the same reference numerals. In this respect, the description may not be repeated. It is noted that in the embodiment of the double-stroke cylinder according to FIGS. 12 and 13, the cylinder tube 49 and the protective tube 50 in connection with the cylinder head 41 and the cylinder base 42 form long cylinder spaces 63, 65 that the piston 53 around the maximum stroke, in particular can be adjusted to operate smoke flaps.

In the upper part of FIG. 12 above a main longitudinal axis 67, the piston 53 is shown in a left or upper position, in which the piston rod 51 is fully extended. In contrast, in the lower part of FIG. 12 below the main longitudinal axis 67, the piston 53 is in its right or lower end position, which corresponds to the retracted position of the piston rod 51. 13, the piston 53 an intermediate position corresponding to a partial stroke of the piston rod 51.

The embodiment of the double-stroke cylinder according to FIGS. 12 and 13 differs from that in FIG. 7 initially in that within a bore 68, see FIG. 13, the piston rod and within a bore 69 within the locking rod screwed to the piston rod in the region of the piston 70 a guide rod 71 is mounted coaxially. At the end of the guide rod located in the bore 68, the latter is provided with a likewise slidable stop 72 - see FIG. 13 - which can come to rest on a tapered end face 73 of the locking rod 70 and forms a stop there. At the opposite end, an additional locking bar 74 of larger diameter is screwed onto the guide bar 71 and can be locked to limit the partial stroke.

So that the additional locking rod 74 can be locked outside a rear locking piston 75, the locking piston 75 is provided with an outwardly open extension 76, to which an outer locking cylinder 77 is attached. In the locking cylinder 77, an additional locking piston 78 is slidably supported, which is supported against a spring 79, only indicated, on a stop cover 80. The parts 77 - 80 are used in conjunction with the elements still to be discussed to limit the stroke, ie to lock the piston rod during a partial stroke. For this purpose, the additional locking piston 78 has in particular a sleeve-like section 81, under which balls 82 can be locked by engaging in an annular groove 83 in the additional locking rod 74. There is then a set of small balls lying in a ring around the circumference of the groove 83 in the groove.

Similarly, sets of smaller balls 84 and 85 without a ball sleeve are mounted in the areas of the sleeve-like sections 86 and 87 so that they can be inserted into annular grooves 88, 89 in the locking bar 70 and the piston rod 89, respectively. So that the balls 82 and 84 cannot fall into the cavities released in an uncontrolled manner when the additional locking bar 74 or locking bar 70 is withdrawn, spring-loaded displaceable support parts 90, 91 are provided which support the balls in these cases.

The connection between the blind hole 62 and a bolt pressure chamber 92 and the second cylinder chamber 65 is the same as described for FIG. 7. In addition, however, in the embodiment according to FIGS. 12 and 13 there is a connection between the bolt pressure chamber 92 and a bolt pressure chamber 93 via a channel 94 in the extension 76. The channel 94 leads to a reversing valve 95, which has a cup sleeve 96 on one side is under the adjustable pressure of a spring sleeve 97 and can be supported on a valve seat 114. A spring 98, a threaded pin 99 in a nut 100 are used for pressure adjustment. The threaded pin can be locked by a second nut 101.

By adjusting the pretension of the spring 98, it is determined at what pressure in the blind hole 62 the piston rod is pushed into the fully extended position after the lock on the additional locking rod 74 is released. For this purpose, the spring sleeve 97 releases a valve chamber 102 in which the pressure built up therein via the channel 94, a radial bore 103a and a valve bore 103 presses back the cup sleeve 96 against the spring force. The compressed air can therefore flow through radial bores 104, 105 to reach the locking pressure chamber 93 and thus push the additional locking piston 78 back to the right or downward, so that its sleeve-like section 81 releases the balls 82 which come out of the groove 83 can be pushed out when the piston 53 is pushed to the left or up to the fully extended position due to the pressure in the cylinder space 65. As stated, this position is shown in the upper part of FIG. 12. Here, the balls 85 snap into the groove 89 of the piston rod in order to ensure a large locking force or holding force in the fully extended position.

Conversely, if the pressure in the blind hole 62 is below a predetermined pressure level of e.g. Remains 5 bar, the piston only extends by one partial stroke or one ventilation stroke. In this operating state shown in FIG. 13, the pressure in the valve bore 103 is not sufficient to lift the cup sleeve 96 and to establish the connection to the radial bores 104, 105 via the valve chamber 102. In this case there is a leakage air connection between the bolt pressure chamber 93 on the additional bolt piston 78 and the radial bore 105 along the outside of the spring sleeve 97 to the outside. This leakage protection prevents the balls 82 from being accidentally released by moving the additional locking piston 78 when the reversing valve is dirty or worn. The additional locking bar 74 thus remains in the locked right or lower position. When the pressure builds up in the second cylinder space 65, the piston 53 can therefore only move upwards until the stop 72 comes to bear against the end face 73 of the locking rod 70 in the piston rod 51 and holds the piston rod in this position. The balls 85 are released from the groove 89 in the piston rod from the previous return of the piston, which is discussed in connection with the lower part of FIG. 12.

To reset or close the smoke flaps, depending on the variant according to FIG. 12 or 13, one of the two blind holes 61, 62 is pressurized with compressed air strikes, which in this case is not critical. Special reference is made to the lower part in FIG. 12. To reset the piston rod or to close the smoke flap, which is connected to the piston rod, the blind hole 61 is pressurized, which propagates along the piston rod into the overpressure chamber 45 and into the first cylinder chamber 63. As a result, the piston rod 53 is shifted to the right or down to the stop on the cylinder base 42. The balls 84 enter the annular groove 88 of the locking bar 70 and are held there by the sleeve-like section 86 which is pushed over them by spring force. In addition, the guide rod 71 and the additional locking rod 74 are moved to the right or down into the end position via the stop 72, which abuts the end of the bore 68 in the piston rod, which they assume for limiting the stroke or for setting a partial stroke. In this position, the balls 82 fall into the groove 83 in the additional locking bar and are held in this position by the additional locking piston 78 pushed to the left or up under spring force.

It is also noted with respect to FIGS. 12 and 13 that in the two figures the cylinder head 41 and the cylinder base 42 assume positions that are interchanged, which is readily possible due to the construction of the compressed air cylinder, although the blind holes 61 and 62 interchange their functions. By replacing the cylinder head 41 with the cylinder base 42, it is possible to change the attachment of the compressed air cylinder to the blind holes 61 and 62 depending on the installation requirements.

The resetting can take place both from the fully extended position in the upper part of FIG. 12, as described above, and from the partial stroke position in FIG. 13, the balls 85 not needing to be unlocked, since they have not fallen into the groove 89 of the piston rod here.

FIGS. 14 and 15 show the same stroke positions as in FIGS. 12 and 13, but for a compressed air cylinder that has only one cylinder tube 9 according to the embodiment in FIG. 1. In the same way as in FIG. 1, the other parts of this double tube cylinder according to FIGS. 14 and 15, which are not designated, are formed, except for the slight modification of the piston rod 106, which in turn here has a bore 107 for mounting a stop 108 on a guide rod 109 is provided. The guide rod is screwed at its opposite end into an additional locking rod 110, which extends through the locking piston 112 provided with an extension 111 into an outer locking cylinder 113. The outer locking cylinder 113 with the parts mounted in it, including an attached reversing valve 95, is constructed in the same way as the outer locking cylinder 77 with the reversing valve 95, so that there is no need to repeat the description. Different from the embodiment in FIGS. 12 and 13 in the embodiment according to FIGS. 14 and 15 are the cylinder head 1 and the cylinder base 2, for the explanation of which reference is made to the corresponding parts in FIG. 1. Connection channels are provided between a blind hole 27 in the cylinder head 1 and a cylinder chamber 9a or a bolt pressure chamber 22. Analogously, there are connection channels between a blind hole 30 in a cylinder bottom and a second cylinder pressure chamber 9b on the one hand and a bolt pressure chamber 23. The bolt pressure chamber 23 is in turn connected via a channel 94 to the bolt pressure chamber 93 of the additional bolt piston 78.

It should be noted at this point that in all of the embodiments according to FIGS. 12-15 the partial stroke locks tion can be easily solved by pulling out the additional locking piston 78. The rear locking piston 112 can also be easily pulled out together with the outer locking cylinder 113 to release the partial stroke position by inserting a tool into the blind hole 115.

The pressure medium-operated reversing valve 95 can also be used as a connecting valve, in particular of compressed air cylinders, which are designed as single-stroke cylinders, in a line of a pressure medium-operated arrangement for smoke flap actuation.

For this purpose, the reversing valve 95 is provided with a connecting plate 116, see FIGS. 16 and 17. The entirety of the reversing valve 95 and the connecting plate 116 is regarded as a connecting valve. The structure and principle of operation of the pressure-operated reversing valve are the same as described above. The reference numerals of the individual elements of the reversing valve have therefore been retained in FIGS. 16 and 17.

The connection plate 116 is approximately cuboid with at least one flat side 117, which bears tightly on a likewise flat side 118 of the reversing valve. These two elements are held together by Allen screws, not shown, which extend through bores in the connecting plate 119, 120 and are screwed into threaded holes in the reversing valve.

Mounting holes for mounting the sequence valve are designated 121, 122. A first connection bore 123, into which a first connection bore 124 projects transversely, is used to connect a first line which is under the controlled pressure of a pressure medium. This passes into the radial bore 103a of the reversing valve attached. A second connection bore 125 for connecting an outgoing, second line is connected via a tapered bore section i26 to a transverse bore 127, from which a second connection bore and a third connection bore 128, 129 extend at right angles to the second connection bore and to the cross bore. The second and the third connecting bores merge into the radial bores 104 and 105 of the reversing valve mounted. The cross hole is closed by a threaded pin 130.

Depending on the pressure with which the connecting valve 95, 116 constructed in this way is acted upon, this creates a pressure medium-conducting connection between the first connection bore 124 and the second connection bore 125:

If the pressure in the first pressure medium connection 123 does not reach a predetermined minimum value, the cup sleeve 96 is pressed onto the valve seat 114 in the rest position shown in FIG. 16 under the action of the spring sleeve 97 and the spring 98. As a result, a pressure medium-conducting connection between the first connection bore and the second connection bore is interrupted. The pressure at the second connection bore 125 can be compensated to the outside via the third connection bore 129, the radial bore 105 along the outside of the spring sleeve 97. However, if the pressure at the first connection bore 123 is so high that the cup sleeve 96 lifts off the valve seat 114 against the force of the spring 98, then there is a pressure medium-conducting connection between the first connection bore via the first connection bore 124, the radial bore 103a , the valve bore 103, the valve chamber 102, the radial bores 104, 105, which, like the adjoining connection bores 128, 129, are parallel, via the transverse bore 127 to the second connection bore 125.

In the compressed air cylinder arrangement shown schematically in FIG. 18, a single-stroke cylinder 131 and a double-stroke cylinder 132 are provided for actuating a smoke and heat exhaust flap 133 and 134, respectively. A pressure-controlled reversing valve 135, as described above, is integrated with the double-stroke cylinder 132. The compressed air cylinder arrangement also includes a manual control valve 136, the one output of which is connected via lines 137, 138, 139 to unidentified inputs or blind holes of the single-stroke cylinder 131 and the double-stroke cylinder 132 in order to move the smoke and heat exhaust flaps into the closed position. To actuate the smoke and heat exhaust flaps in the opposite direction to open, a further outlet of the manual control valve is connected via lines 140, 141 to the compressed air supply or a blind hole of the double-stroke cylinder 132. A pressure medium line, consisting of sections 143, 144, in which a connecting valve 145 is switched on, is branched off from a connection point 142. The connection valve is in turn pressure-controlled. The pressure medium line, consisting of the sections 143, 144, leads to a compressed air supply or a blind hole of the lifting cylinder 131. If a pressure acting on the line 140 is set on the manual control valve 136, which does not exceed a predetermined pressure, the double lifting cylinder 132 drives the smoke - And heat flap 134 in a first open position, since the reversing valve 135 prevents a further stroke. Since the pressure-controlled connection valve interrupts the pressure medium line, consisting of sections 143, 144, in this pressure range, the smoke and heat exhaust flap 133 is not actuated. - Only in the event of an alarm, when the pressure on the manual control valve exceeds a predetermined pressure, the connection valve 145 transfers this pressure into the section 144 of the pressure medium line and from there into the lifting cylinder 131, which thus places the smoke and heat exhaust flap 133 in the open alarm position pivots. In addition, the reversing valve 135 on the double-stroke cylinder 132 releases the further alarm stroke of the double-stroke cylinder, which opens the smoke and heat vent flap 134 accordingly.

Many variants of the compressed air cylinder arrangement are conceivable in which the connecting valve and the reversing valve, both of which are pressure-controlled and essentially of the same construction, can be used advantageously.

Claims (22)

1. compressed air cylinder with end position locking, in particular for actuating smoke flaps in smoke and heat extraction systems, with a double-sided piston which can be displaced in a counter cylinder with two cylinder spaces by a pressure medium, and with at least one locking device connected to a piston rod,
characterized,
that on both sides outside the closed cylinder spaces (9a, 9b) and adjacent to each of these cylinder spaces, a locking piston (3 or 4) can be moved concentrically to the piston rod (10), which with the adjacent cylinder space (9a or 9b) in pressure medium Conductive connection is that each locking piston (3, 4) has a sleeve-like section (e.g. 4a), which in a locking position engages radially guided balls (11), which in an annular, with the piston rod (10) communicating groove (e.g. 10a) partially engage, and which releases the balls radially outwards when it has moved axially away from them. 2.Compressed air cylinder with end position locking, in particular for actuating smoke flaps in smoke and heat extraction systems, with a double-sided piston which can be displaced in a counter cylinder with two cylinder spaces by a pressure medium, and with at least one locking device connected to a piston rod,
characterized,
that on both sides outside the closed cylinder spaces (9a, 9b) and adjacent to each of these cylinder spaces, a locking piston (3 or 4) is concentrically displaceable to the piston rod (10), which with the neighboring Cylinder chamber (9a or 9b) in pressure medium conductive connection is that each locking piston (3, 4) has a sleeve-like section (e.g. 4a), which engages radially and rollable balls (11) in a locking position, which in an annular, with the Partially engage the piston rod (10) in the connected groove (for example 10a) and which releases the balls radially outwards when it has moved axially away from them. 3. Air cylinder according to claim 2,
characterized,
that the balls in the lowered position in the groove in the circumferential direction of the groove abut each other in a ring shape. 4. Air cylinder according to one of claims 1-3,
characterized,
that the double-sided piston (12) is fastened between the piston rod (10) and a locking rod (7) which is aligned with the piston rod, and that in addition to the piston rod (10) the locking rod (7) with an annular groove (7a) each partial recording of the locking balls (11) is provided. 5. Air cylinder according to one of claims 1-4,
characterized,
that each locking piston (3, 4) is pressed by at least one spring (17) in the direction of the adjacent balls (11). 6. Air cylinder according to one of claims 1-5,
characterized,
that each locking piston (3, 4) has a section protruding from the compressed air cylinder. 7. Air cylinder according to one of the preceding claims,
characterized,
that on the locking piston (3), which is displaceable on the piston rod (10), an inner and an outer grooved ring (14, 15) are arranged. 8. Air cylinder according to one of the preceding claims,
characterized,
that each of the two ends of the compressed air cylinder is closed by a stop cover (5) which forms at least one spring receiving area (support surface 5b) and a stop for the locking piston, each concentric with the piston rod (10) or locking rod (7). 9. Air cylinder according to claim 8,
characterized,
that the section of the locking piston (3) emerging from one of the stop covers (5) has a bore (3a) through which the piston rod (10) is displaceably guided. 10. compressed air cylinder according to claim 8 or 9,
characterized,
that the section of the locking piston (4) projecting from the other stop cover (5) is closed and that in this section a support part (8) is slidably mounted, which is aligned with the locking bar and is pressed against its end face by a spring (18). 11. compressed air cylinder according to one of claims 1, 3 - 10,
characterized,
that the balls (11) are mounted in a ball sleeve (6a, 6b) in a rollable and radially displaceable manner. 12. Air cylinder according to claims 1, 2, 3, 7 and 8,
characterized,
that one of the locking pistons (4), the support part (8) and the stop cover (5) with the spring receiving space are arranged at least partially overlapping one another concentrically. 13. Air cylinder according to one of the preceding claims,
characterized,
that two pressure medium connections (blind holes 61, 62) of the two cylinder spaces (63, 65) are arranged on the cylinder head (41) and that the cylinder head and the cylinder base (42) are interchangeable. 14. Air cylinder according to one of claims 1-12,
characterized,
that one of the pressure medium connections (blind hole 27 or 30) of the two cylinder spaces (9a, 9b) is arranged on the cylinder head (1) and the cylinder base (2) and that each pressure medium connection is opposed by a similarly shaped blind connection (blind hole 28 or 29) . 15. Air cylinder according to one of the preceding claims,
characterized,
that the cylinder head (1), the cylinder base (2), the locking pistons (3, 4), the stop cover (5), the ball sleeves (6a, 6b), the locking rod (7) and the support part (8) from an AlCuMgPb Alloy. 16. Air cylinder according to claim 15,
characterized,
that the piston rod (10) is made of V2A steel. 17. Compressed air cylinder according to one of claims 1-9, 12-16,
characterized,
that to form the compressed air cylinder as a double-stroke cylinder coaxial to the piston rod (51) and with respect to this up to a stop on the piston rod (stop 72, end face 73) an additional locking rod (74) is provided, which limits a partial stroke of the piston rod and in this partial stroke position protrudes from one of the two locking pistons (75), that an external locking cylinder (77) is arranged on the outside of this locking piston (75), in which an additional locking piston (78) is slidably mounted, which has a sleeve-like section (81) in the partial stroke position balls ( 82) which engages in an annular groove (83) in the additional locking bar and is otherwise radially movable, and which releases the radially outwardly movable balls (82) when it has moved axially away from them, and that the additional locking piston (78) via a pressure-controlled reversing valve (95) when a predetermined pressure is exceeded with the closest adjacent cylinder space ( 65) is connected. 18. A compressed air cylinder according to claim 17,
characterized,
that a guide rod (71) is slidably mounted in a bore (68) in the piston rod (51), one end of which has a stop (72) which limits the mutual displacement of the piston rod and the guide rod, and the other end with the additional locking rod (74) is connected. 19. Air cylinder according to claim 17,
characterized,
that the reversing valve (95) a leakage air connection (channels 104, 105) from a bolt pressure chamber (93) on the additional bolt piston (78) to the outside. 20. Air cylinder according to claim 17 or 19,
characterized,
that the reversing valve (95) has a spring-loaded cup sleeve (96) which closes on one side a valve bore (103), which is connected to a pressure medium supply, opposite a valve chamber (i02), in the radial bores (104, 105 ) lead to. 21. Compressed air cylinder according to claim 20,
characterized,
that the valve bore (103) of the reversing valve (95) is conductively connected to the closest adjacent cylinder chamber (65) pressure medium and that the radial bores (104, 105) lead to a bolt pressure chamber (93) in the outer bolt cylinder (77). 22. Compressed air cylinder arrangement, in particular using at least one lifting cylinder according to one of claims 1-16,
characterized,
that a switching valve is arranged in a pressure medium line to the lifting cylinder, which comprises a pressure-controlled reversing valve (95) and a connection plate (116) attached to it, that the reversing valve (95) has a spring-loaded cup sleeve (96) on a Side a valve bore (103), which is connected to a pressure medium supply, terminates opposite a valve chamber (102), in which radial bores (104, 105) open, that the connection plate (116) has a first connection bore (123) and a second connection bore (125), to which the pressure medium line can be connected, and that the connection bores via Connection bores (128, 129) are directly connected to the radial bores (104, 105) of the reversing valve.

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