EP0870888B1

EP0870888B1 - External unit for door lock

Info

Publication number: EP0870888B1
Application number: EP19980302675
Authority: EP
Inventors: Luis Angel Ruano
Original assignee: Talleres de Escoriaza SA
Current assignee: Talleres de Escoriaza SA
Priority date: 1997-04-11
Filing date: 1998-04-06
Publication date: 2003-06-04
Anticipated expiration: 2018-04-06
Also published as: ES1036905Y; EP0870888A2; RU2142041C1; EP0870888A3; ES1036905U

Description

The invention relates to an external unit for controlling access via doors with a lock which can only be operated from inside. The external unit is one which is actuated by means of a combination cylinder which is operated by means of a key, to make it possible for a door, which is fitted with a lock, which is designed to only be opened from inside, to also be opened from outside, though only by someone who has the said key which can be used to block the said access from outside without affecting the opening of the door from the inside which can occur at any time.
In this respect, a typical example is that of emergency doors which are provided, on the inside, with anti-panic bars which actuate the opening of the lock to enable the escape of persons (as in large commercial areas, hospitals, sporting and cultural precincts, factories, etc.). Nevertheless, the external unit can generally be applied in all cases where there is a door which is basically provided as an exit, but where, without affecting opening from inside, doors are also able to be opened occasionally from the outside by whoever has the key to do so.
In this field, there is known the general concept of an exterior unit having a combination cylinder which, by means of a mechanism of the unit itself, is able to lock, against rotational movement, a rotating shaft housing which is externally coupled with an actuating handle, while towards the inside, there is coupling with a connection shaft (in the form of a spindle, square-sectioned bar, fillet, etc.) for unlocking the door from inside.
At the same time, it is usual, in cases where several locks are required for large areas, for the installation of these to be carried out in two stages; a first stage in which the locks with their original cylinders are installed, and a second stage in which, for a carefully chosen security operation, the original cylinders are replaced by different ones and the relevant training in the use of the system of locks, for the project as a whole, is carried out.
In this case, it is desirable that the substitution of the cylinders be carried out in the simplest and quickest way possible.
Now, the solutions currently provided are still complicated and slow. In this respect, the solution in which the combination cylinder is integrated into a capsule which can be coupled to the casing of the unit in which the rest of the mechanism is contained, is known in particular. This solution notably complicates the design of the unit, increases production costs and makes the substitution more laborious, as it is necessary to disassemble the capsule in relation to the lock, then to disassemble the rotor in relation to the capsule, to remount the rotor in the capsule and re assemble the capsule into the lock; additionally, an extra part (the capsule) which is visible from outside, makes it necessary to have a store of more parts with different possible surface finishes.
In view of the above, the new exterior unit which is now proposed, seeks to provide a device for which the assembly of the combination cylinder is extremely simple, enabling simple and quick substitution.
According to the invention there is provided an exterior unit for controlling access via doors with a lock which can normally only be operated from the inside, comprising a combination key cylinder to prevent or enable access from the exterior, a fixed support housing in which the combination cylinder is insertable from the front of the exterior unit, by sliding it longitudinally into the support housing, a sliding catch incorporated in the support housing and co-operating in the inserted position of the cylinder, with an aligned transverse cavity which is provided in at least one side of the housing of the combination cylinder and into which the tip of the said catch is slideable to retain the combination cylinder, a spring for urging the catch into its locking position, the catch having, at the rear, a conical tail which is axially guided in a chamber of the support housing and which has a radial threaded hole which is accessible from the back of the exterior unit, and a grub screw, which has a conical tip which is complementary to the conical form of the conical tail, located in this threaded hole, the grub screw being screwable between a first position in which its conical tip is contained within the threaded hole and a second position in which it extends into the enclosure, to slidingly engage the side of the conical tail element and maintain the catch in its combination cylinder retaining position.
The operativeness of this new device is extremely simple and quick. When the grub screw is loosened to the point where it reaches its enclosed position, the retention on the conical tail element is removed and the renewed action of the spring forces the retraction of the catch to its locking position, in which it comes out of the transverse cavity of the housing of the combination cylinder, and the latter can then be inserted or withdrawn, through the front of the unit, by a simple, axial, sliding movement in relation to the support housing. Thus, the substitution of the cylinder only requires the loosening of the grub screw, once the unit has been removed from the door, which is something that has to be done anyway. To facilitate the mounting of the support housing component, without the catch coming out of the enclosure in which it sits, this mounting can take place with the grub screw in its protruding position in which it retains the conical tail element of the catch. Once the support housing has been mounted, it is the wall of the unit which stops the catch from coming out. The same applies to disassembly of this support housing.
This invention also seeks to provide a simple, economic and efficient mechanism which, through actuation of the cylinder (by the combination key), is able to lock the handle with which the proposed external unit is fitted.
In a preferred embodiment of the invention, the mechanism consists in that, when turning the key, of the combination cylinder, in the opening direction, the rotational movement of the projection of this acts on one or other of the first radial faces of a tilting cam element which is symmetrical in relation to the vertical plane which contains the virtual axis of the said combination cylinder, the tilting cam element forming, an upwards, obtuse, re-entrant angle which, by through each apex, connects with respective retention sides, the tilting cam element taking up an untilted position, with its plane of symmetry being vertically aligned, and a tilted position in which one of the two apices abuts against a side of the said exterior unit and the other apex slightly extends beyond the said vertical plane containing the virtual axis of the combination cylinder, and a sliding engaging plate, which is guided vertically and has a lower obtuse angular projection, which corresponds to the re-entrant angle of the tilting cam element, engaging the tiling cam element, from above, under the force of a spring, and a window which is formed by a circular part extends into a straight vertical part there below, the circular part having a diameter greater than that of a revolving shaft housing in which, directly or indirectly, an external handle can be connected, and in this way, a transmission shaft can be connected to the opening mechanism of the internal lock of the door, and the straight, vertical part has a width which is greater than the distance between two opposite, parallel flats of the revolving shaft housing, the engaging plate having a lower non-locking position, and an upper locking position, these two positions corresponding, respectively, to the untilted and tilted positions of the tilted cam element, and being such that, in the position of non-locking, the obtuse angular projection is engaged with its corresponding re-entrant, obtuse angle and the circular part of the window is coaxial with the rotating shaft housing and, in the locking position, the obtuse, angular projection has its vertex supported against one of the respective two retaining sides and the said straight, vertical part of the window is engaged with the flats of the rotating shaft housing. In the tilted position of the tilted cam element, one or the other of two second radial front faces of the latter is interposed in the return path of the said projection of the combination cylinder.
The functioning of this mechanism is that the projection of the cylinder tilts the tilted cam element, and, inclined by direct action between the re-entrant of this cam element and the projection of the sliding engaging plate, this engaging plate rises until the straight, vertical part of its window is engaged with the flats of the rotating shaft housing to which the handle is connected, such that this handle cannot turn. In this situation, the engaging plate cannot descend, because the tilting cam element has reached its point of maximum tilting in which the lower, angular projection of the engaging plate now rests on a side of this tilting cam element such that it pushes this cam element to its extremity of tilting. On turning the key in the direction of locking, the projection of the cylinder engages the second radial face, and the tilting cam is forced to tilt in the opposite direction, towards the initial position in which the engaging plate descends, pushed by its spring and by the force of gravity acting on it, until it becomes re engaged between the projection and angular re-entrants.
The symmetrical design of the tilting cam element enables functioning in both directions of rotation of the cylinder, in order to enable use of the unit in doors opening either to the left or to the right. Once the right- or left-hand side of the door has been chosen, there is, in the said non-tilted position of the said tilting cam element, a peg which is anchored to the body of the external unit and which is engaged with that side of the two retaining sides which is in the rear position in relation to the direction of tilting of the said tilting cam element, this position being produced by the opening action of the said combination cylinder. For this reason, the peg, of the two of these which were originally provided for in the production of the proposed external unit, which serves no purpose, is removed.
The possibility of indirect connection of the operating, exterior handle concerns the setting up of a mechanical link, between this and the rotating shaft housing, which, like a mechanical fuse which is destroyed or broken when a force greater than a set value, considered as representing an attempted trespass, is applied to the handle, such that, here, the handle becomes loose and its movement is not transmitted to the shaft housing and neither, therefore, is it transmitted to the opening mechanism of the internal lock.
The invention also seeks, in a better embodiment thereof, to provide a highly simple and economic mechanism for rotationally actuating a shaft housing of the external unit which is connected to the opening mechanism of the interior lock of the door, by means of the combination cylinder, but without this shaft housing of the exterior unit having an operating handle.
Accordingly, in this embodiment this new mechanism is that, when turning the key of the combination cylinder, in the opening direction, the rotational projection of the latter engages one or the other of two impelling parts which are disposed symmetrically in relation to the initial idle position of the rotational projection, the impelling parts belonging to a sliding thrusting means which is guided vertically and which, on its upper part, incorporates a thrusting arm-piece which is positioned in a neck which is formed in the rim of a draw-plate which rotates together with a shaft housing without an external actuating handle and which has a transmission shaft, which can be connected to the opening mechanism of the said interior lock of the door, coupled to it.
The functioning of this mechanism is that while the cylinder is not rotated, the door cannot be used from outside. Only by turning the key, (via the mechanism of the sliding thrusting means), does the draw-plate effect the turning of the shaft housing which causes the opening of the interior lock, the door being opened from the outside while the key is held turned. When the rotation of the key is reversed, the interior lock is re-applied.

DRAWINGS AND REFERENCES

The invention will now be described in greater detail by way of example only, with reference to the drawings, in which:-
Figure 1 is the right-hand side view of an exterior unit in accordance with the present invention, where the side wall, has been conveniently partially removed to show the nature of the combination cylinder;
Figure 2 is a front view of the exterior unit of figure 1, with the front partially removed to show the nature of the combination cylinder,
Figure 3 is an expanded view of detail III which appears encircled in figure 2, though showing here only the support housing and the corresponding part of the combination cylinder;
Figure 4 is a section taken along the line IV-IV in figure 3, but incorporating the catch and the enclosed screw in positions of non-holding and passivity;
Figure 5 is a view similar to figure 4, but with the catch and the enclosed screw in its respective holding and active positions;
Figure 6 shows a frontal view, without its front, of an exterior unit with a handle, and of the corresponding rotating locking mechanism, located in an idle position, or one of non-engagement;
Figure 7 is a view similar to figure 6, but showing the position of the engaging plate of the mechanism in relation to the turning of the handle;
Figure 8 is a view similar to figure 6, but showing an exterior unit without a handle and having a rotational action mechanism of the rotating shaft housing which is shown in its idle position;
Figure 9 is a view similar to figure 8, but showing the position in which the rotating shaft housing has been turned to the point at which it enables the opening of the interior lock of the door;
Figures 10 and 11 show corresponding views and sections of the rotating shaft housing;
Figures 12 and 13 show corresponding views and sections of the sliding engaging plate;
Figures 14 and 15 are corresponding views and sections of the tilting cam element;
Figures 16 and 17 are corresponding views and sections of the draw-plate, and
Figures 18 and 19 are corresponding views and sections of the sliding thrusting means.
The following reference numbers are used in the diagrams:
1 exterior unit
1a front section of the unit (1)
1b back section of the unit (1)
1c side of the unit (1)
2 combination cylinder
2a rotating projection
3 support housing
3a housing cage
4 catch
5 cylinder's transverse cavity (2)
6 spring
7 conical tail element
8 threaded hole
9 grub screw
9a conical tip of screw (9)
10 tilting cam element
10a first radial faces of cam (10)
10b obtuse angular re-entrant of cam (10)
10c apices of cam (10)
10d retaining sides of cam (10)
10e second radial faces of cam (10)
11 spring
12 sliding engaging plate
12a obtuse, angular projection of engaging plate (12)
13 window of engaging plate (12)
13a circular part of window (13)
13b straight vertical part of window (13)
14 rotating shaft housing
14a vertical, parallel flats
15 transmitting shaft
16 abutment pin
17 sliding thrusting means
17a impelling parts of thrusting means (17)
17b upper thrusting arm-piece of thrusting means (17)
18 draw-plate
18a neck of plate (18)
19 working handle
Referring to the drawings, a preferred embodiment of the new exterior unit, which is aimed at blocking and facilitating entry from outside via doors which are originally fitted with a lock that can only be worked from inside, by means of an anti-panic push-bar, or by other generally known means, is shown.
The exterior unit (1) is actuated by means of a combination cylinder (2) which is operated by a key, and is provided with a rotating shaft housing (14) which is rotationally connected with the action of opening the interior lock of the door and which may or may not have an operating handle (19) connected on the outside. When one wishes to temporarily have the door openable from the outside, without having to use the key each time, the exterior unit (1) will be fitted with an outer handle (19) which can be rotationally locked/unlocked by means of the key, depending on whether one wishes to prevent or allow access from outside as figures 6, 7 and 10 to 15 show. When it is required that the key be used each time someone wishes to pass through from outside, the handle (19) is omitted from the exterior unit (1). In the first case, the turning of the key locks or unlocks the turning of the handle (19). In the second case, the key is used to effect the turning, of the rotating shaft housing (14), which rotation is transmitted to the mechanism which opens the interior lock, as shown by figures 8,9 and 16 to 19.
A first characteristic of the exterior unit (1) is the mounting of the combination cylinder (2) in the exterior unit (1) (figures 1 to 5). This combination cylinder (2) is mounted from the front (1a) of the exterior unit (1), by sliding it longitudinally in a support housing (3) which is fixed and which incorporates a catch (4). The catch 4, in the operating position of the combination cylinder (2), is axially opposite a corresponding transverse cavity (5) which is provided in at least one side of the elastic body of the combination cylinder (2) and which has a transverse section which has sliding adjustment in relation to that of the tip of a said catch (4). The catch has two positions in one of which it retains the combination cylinder (2), and in the other of which it releases the combination cylinder (2), these positions being determined, respectively, by the compression and release of a spring (6) associated with a said catch (4). This catch (4) incorporates, at the rear, a conical tail (7) which is axially guided in an enclosure (3a) of the support housing (3) and which is faced, in a radial direction, by a threaded hole (8) which is accessible from the back (1b) of the exterior unit (1). A grub screw (9), which has a conical tip (9a) which is complementary to the conical form of the conical tail (7), operates in this threaded hole, the said grub screw (9) occupying passive and active positions in which, respectively, its conical tip (9a) is retained in the threaded hole (8) or penetrates into the said enclosure (3a), being slidingly applied on to the side of the conical tail element (7) up to a point of maximum penetration in which the said catch (4) occupies its position of retaining the combination cylinder (2). On loosening the grub screw (9) to its passive position, the catch (4) and its conical tail element (7) are forced (figure 4) by the spring (6) into the retracted position of non-retention, in which the combination cylinder (2) can be inserted or withdrawn from the front (1a) by a simple axial sliding operation in relation to the support housing (3). The grub screw (9) is only accessible from the back section (1b) and is therefore inaccessible when the outer unit (1) is fixed to the door from the inner side thereof. When the grub screw (9) is screwed into its active position, the side of its conical point (9a) exerts a force on an inclined surface of the conical tail element (7) and pushes it forward, such that the catch (4) penetrates the transverse cavity (5) (figure 5), adopting its retaining position which immobilizes the combination cylinder (2) section, it being possible to also use this position when mounting the support housing (3) in the exterior unit (1), in order to prevent the catch (4) from coming out of the enclosure (3a).
For the case in which an exterior handle (19) (figures 6 and 7) is required, when turning the key, of the said combination cylinder (2), in the direction of opening, the rotational projection (2a) thereof acts on one or other of the first radial front faces (10a) of a tilting cam element (10) which is symmetrical in relation to the vertical plane which contains the virtual axis of the combination cylinder (2). The tilting cam element (10) forms an upwardly, extending obtuse, re-entrant angle (10b) which, by means of each apex (10c), is connected to respective retention sides (10d), the said tilting cam element (10) being movable between an untilted position, with its plane of symmetry being vertically aligned, and a tilted position in which one of the two apices (10c) abuts against a side (1c) of the said exterior unit (1) and the other apex (10c) slightly extends beyond the vertical plane containing the virtual axis of the combination cylinder (2). A sliding engaging plate (12), which is guided vertically and has a lower obtuse angular projection (12a), which corresponds to the re-entrant angle (10b) of the tilting cam element (10), is applied against the said tilting cam element (10), from above, under the force of a spring (11). A window (13) is formed by a circular part (13a) which merges below with a straight vertical part (13b), the circular part (13a) having a diameter greater than that of a rotatable shaft housing (14) to which, directly or indirectly, an external handle (19) is connected, and in this way, a transmission shaft (15) of any suitable kind which can be connected to the mechanism for opening the internal lock of the door, can be connected. The straight, vertical part (13b) has a width which is more than the distance between two opposite, parallel flats (14a) of the revolving shaft housing (14), the engaging plate taking up both a lower locking position, and an upper non-locking position, these two positions corresponding, respectively, to the untilted and tilted positions of the tilted cam element (10). In the non-locking position, the obtuse angular projection (12a)) is coupled with the corresponding re-entrant, obtuse angle (10b) and the said circular part (13a) of the window (13) is coaxial with the rotating shaft housing (14). In the entry blocking position, the said obtuse, angular projection (12a) has its vertex supported against one of the respective two retaining sides (10d) and the straight, vertical part (13b) of the window (13) is engaged with the flats (14a) of the rotatable shaft housing (14). In the unlocked position (figure 6), the shaft housing (14) can rotate freely in the circular part (13a) of the window (13) of the engaging plate (12). In the locking position (figure 7), on the other hand, the flats (14a) are positioned between the edges of the straight, vertical part (13b) of the window (13), and the rotatable shaft (14) cannot turn, so that neither can the rotating handle (19) turn; the raising of the engaging plate (12) is produced by the action of an inclined surface between the re-entrant angle (10b) and projecting angle (12a), when the tilting cam element (10) is tilted. In the locking position, the angular projection (12a) falls on the retaining side (10d) and facilitates the movement of the tilting cam element (10) against its abutment on the side (1c) of the exterior unit (1).
In the tilted position of the tilting cam element (10), one or other of second radial faces (10e) of the latter is interposed in the path of return of the projection (2a) of the combination cylinder (2), and therefore, in order for disengagement to occur, the counter rotation of the projection (2a) falls on the second radial face (10a). The cam element (10) tilts until the apex (10c) passes the point of the angular projection (12a) and the spring (11) makes the engaging plate (12) descend to its initial position.
In the non-tilted position of the tilting cam element (10), there is a pin (16) which is attached to the body of the exterior unit (1) and which engages one of the two retaining sides (10d) which is in a rear position in relation to the direction of tilting of the said tilting cam element (10) and which is produced by opening movement being exerted on the combination cylinder (2). When produced, the exterior unit (1) is provided with two of these pins (16) in symmetrical positions, and one of these, the one which is not necessary for the given right or left hand side of the door into which it is installed, is removed.
It is also provided for that the connection between the handle (19) and the shaft housing (14) is destructible should a force be applied, to a handle concerned, which is above a predetermined security value, such that the handle (19) becomes loose, before the interior lock can be opened or damaged, acting as a 'mechanical fuse' in the event of undue handling or of vandalism, destroying the handle which is simple and inexpensive to replace, while other mechanisms which are more costly and sensitive, are maintained.
In the case of figures 8 and 9 where the exterior handle 19 is not wanted, when turning the key of the combination cylinder (2), in the opening direction, the projection (2a) of the latter engages one or the other of two impelling parts (17a) which are disposed symmetrically in relation to the initial idle position of the said projection (2a), said impelling parts (17a) belonging to a sliding thrust means (17) which is guided vertically and which, at its upper part, incorporates a thrust arm-piece (17) which is positioned in a neck (18a) which is formed in the rim of a draw-plate (18) which rotates together with a shaft housing (14) without an external actuating handle (19) and which has a transmission shaft (15) of any suitable kind which can be connected to the opening mechanism of the said interior lock of the door, coupled to it. While the key is maintained in a turned position, the door can be opened; when the key is no longer in this position, the door is re-locked.
The nature of the present invention having, like its production, been sufficiently described, it merely remains to add that, both in whole and in part, it is possible to introduce changes in form, material and arrangement, without departing from the fundamental invention as defined in the appended claims.

Claims

An exterior unit (1) for controlling access via doors with a lock which can normally only be operated from the inside, comprising a combination key cylinder (2) to prevent or enable access from the exterior, a fixed support housing (3) in which the combination cylinder (2) is insertable from the front (1a) of the exterior unit (1), by sliding it longitudinally into the support housing (3), a sliding catch (4) incorporated in the support housing (3) and co-operating in the inserted position of the cylinder (2), with an aligned transverse cavity (5) which is provided in at least one side of the housing of the combination cylinder (2) and into which the tip of the said catch (4) is slideable to retain the combination cylinder (2), a spring (6) for urging the catch into its locking position, the catch (4) having, at the rear, a conical tail (7) which is axially guided in a chamber (3a) of the support housing (3) and which has a radial threaded hole (8) which is accessible from the back (1b) of the exterior unit (1), and a grub screw (9), which has a conical tip (9a) which is complementary to the conical form of the conical tail (7), located in this threaded hole (8), the grub screw (9) being screwable between a first position in which its conical tip (9a) is contained within the threaded hole (8) and a second position in which it extends into the enclosure (3a), to slidingly engage the side of the conical tail element (7) and maintain the catch in its combination cylinder retaining position.
Exterior unit as claimed in claim 1, further comprising a projection (2a) on the combination cylinder (2) and rotatable therewith, a tilting cam element (10) which is symmetrical in relation to the vertical plane which contains the virtual axis of the combination cylinder (2), and having first radial front faces engageable by the projection (2a), the said tilting cam element (10) forming, upwards, an obtuse, re-entrant angle (10b) which, by means of each apex (10c), is connected with respective retention sides (10d), the tilting cam element (10) being moveable between an untilted position, with its plane of symmetry being vertically aligned, and a tilted position in which one of the two apices (10c) abuts against a side (1c) of the exterior unit (1) and the other apex (10c) slightly extends beyond the said vertical plane containing the virtual axis of the combination cylinder (2), a sliding engaging plate (12), which is guided vertically and has a lower obtuse angular projection (12a), which corresponds to the re-entrant angle (10b) of the tilting cam element (10), the sliding engaging plate (12) being engageable with the tiling cam element (10), from above, under the force of a spring (11), and a window (13) is formed by a circular part (13a), connected there below to a straight vertical part (13b), the circular part (13a) having a diameter greater than that of a revolving shaft housing (14) to which, directly or indirectly, an external handle (19) can be connected, and by means of which, a transmission shaft (15) which is connectable to the opening mechanism of the internal lock of the door, and the straight, vertical part (13b) having a width which is greater than the distance between two opposite, parallel flats (14a) on the revolving shaft housing (14), the engaging plate (12) being moveable between a lower locking position, and an upper non-locking position, these two positions corresponding, respectively, to the untilted and tilted positions of the tilting cam element (10), the engaging plate (12) in the non-locking position engaging with its obtuse angular projection (12a) the re-entrant, obtuse angle (10b) of the tilting cam (10) and having the circular part (13a) of the window (13) coaxial with the rotating shaft housing (14), the engaging plate (12) in its locking position having the vertex of the obtuse, angular projection (12a) supported against one of the respective two retaining sides (10d) of the tilting cam (10) and having the straight, vertical part (13b) of the window (13) aligned with the flats (14a) of the rotating shaft housing (14).
A unit, as claimed in claim 2, characterised in that, in the tilted position of the tilting cam element (10), one or other of second radial faces (10e) thereof is interposed in the path of return of the projection (2a) of the combination cylinder (2), and therefore, in order for disengagement to occur, the counter rotation of the projection (2a) of the combination cylinder engages the second radial face (10a), of the cam element (10) and the cam element (10) tilts until the appropriate apex (10c) of the tilting cam (10) passes the point of the angular projection (12a) of the engaging plate (12) and the engaging plate spring (11) causes the engaging plate (12) to descend to its initial position.
A unit, as claimed in claim 2 or 3, characterised in that a pin (16) is attached to the body of the said exterior unit (1) and is engageable with that one of two retaining sides (10d) of the tilting cam element in its non-tilting position which is in a rear position in relation to the direction of tilting of the tilting cam element (10) when an opening movement of the combination cylinder (2) takes place.
A unit, as claimed in claim 1, characterised by a sliding thrusting means (17) which is guided vertically and which, on its upper part, incorporates a thrusting arm-piece (17) which is positioned in a neck (18a) which is formed in the rim of a draw-plate (18) which rotates together with the shaft housing (14) without an external actuating handle (19) and which has a transmission shaft (15) which can be connected to the opening mechanism of the interior lock of the door and two impelling parts (17a) located on the thrusting means (17) which are disposed symmetrically in relation to the initial idle position of the rotational projection (2a), one or other of the two impelling parts being engaged by the rotary projection (2a) of the combination cylinder (2) when the combination cylinder turns in the opening direction.