A SAFETY DEVICE FOR DOOR OPERATING APPARATUS

Abstract: A safety device (11) for door operating apparatus comprises a tripping member (19) having connection means (19A) for connecting it to a power operated double-acting door actuator (12), the tripping member being movable to a tripping position against the action of a predetermined load (24), and a breaker device (23) for the door actuator (12), said breaker being operatively connected to the tripping member. The breaker device is adapted in response to movement of the tripping member (19) to the tripping position to operate a control device (13) to cause it to discontinue supply of energy to the door actuator (12). The tripping member (19) is movable against said predetermined load (24) in one direction to a first tripping position and in the opposite direction to a second tripping position, and the breaker device (23) is adapted in both tripping positions to operate the control device (13) to cause it to discontinue supply of energy to the door actuator (12). The tripping member may be a tripping lever (19) which is mounted on a fixed pivot pin (18) on a support (15) to pivot in opposite directions between two stop positions defined by abutments (15/19C), the connection means (19A) being positioned on the tripping lever at a distance from the pivot pin (18).

Description: A safety device for door operating apparatus This invention relates to door operating apparatus and, more particularly, to a safety device for door operating appara- tus . A safety device of the kind with which the invention is con¬ cerned can be used to stop a door actuator of the door oper¬ ating apparatus if the opening or closing movement of the door being operated is impeded by a force acting on the door and exceeding a certain given value, e.g. a value specified by authorities or in regulations. There are known safety devices which function properly when it is the closing movement of the door that is impeded, e.g. by an object which is stuck between the edge of the door leaf and the door frame. An example of such a device is disclosed in SE-B-456684. However, there is a great demand for a safety device of the kind indicated which functions reliably to stop the door actuator whenever the movement of the door is impeded by a force exceeding a predetermined value, whether the door is opening or closing. Such a dual safety function cannot read- ily be accomplished just by doubling a single-acting safety device. A primary object of the invention is to provide a safety device of the kind indicated which is double-acting in the sense explained above. To this end, the safety device is constructed as set forth in the independent claim. The dependent claims recite features of preferred embodiments of the safety device according to the invention. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings . Fig. 1 is a diagrammatic side view of a door operating appar¬ atus incorporating a safety device according to the inven¬ tion, the apparatus being shown in a rest position, i.e., a position in which no load acts on the door actuator; Fig. 2 is a diagrammatic plan view of the safety device of Fig. 1; Figs 3 and 4 are enlarged fragmentary views of the safety device of Fig. 1 showing the safety device in two different states of the safety device, namely, in Fig. 1 during a nor¬ mal opening or closing movement and in Fig. 4 during an open¬ ing or closing movement in which the movement of the door being operated is impeded by an excessive force that causes the safety device to operate to trigger stopping of the door actuator. The illustrated preferred embodiment of the safety device according to the invention is incorporated in a door operat- ing apparatus which comprises, in addition to the safety device which is generally designated by 11, a door actuator in the shape of a double-acting pneumatic piston and cylinder assembly 12 with an associated control and air supply device, which is represented by a block 13 in Fig. 1. The cylinder of the piston and cylinder assembly 12 is pivotally connected to the safety device 11 and the piston thereof is connected to a pivotally movable door leaf 14 to be operated. The safety device 11 comprises an elongated base or support plate 15 having openings 16 for attachment screws (not shown) by which the plate can be attached in a suitable position on a wall or door frame, for example. Halfway between the ends of the base plate a pair of bearing lugs 17 are fixedly secured to the upper side (as viewed in the drawings) of the base plate. A transverse pivot pin or shaft 18 is journalled in the bearing lugs 17. At the outer sides of the bearing lugs 17 a pair of parallel rocker arms 19 are secured to the pivot pin. These rocker arms extend from the pivot pin away from the base plate 15 and adjacent their outer ends have apertures 19A for receiving trunnions 12A of the pneumatic piston and cylinder assembly 12. One of the rocker arms 19 is welded to the pivot pin 18 while the other rocker arm is secured to the pivot pin by means of set screws 20 or other suitable fasteners . The inner or lower end 19B of the rocker arms 19 is perpen¬ dicular to a plane L containing the axis of the pivot pin 18 and the common axis of the apertures 19A and in the illus¬ trated centered position is parallel to the top side of the base plate 15 and spaced therefrom by a relatively small distance, e.g. 1-1.5 mm. Accordingly, the two rocker arms 19 can swing freely in opposite directions from the illustrated vertical centered position to a slightly inclined position in which one or the other of the corner portions 19C of the rocker arms engages the top side of the base plate 15 to limit the rocking movement. The angular range of movement of the rocker arms 19 may be, for example, 5° in either direc- tion from the illustrated centered position. Between the bearing lugs 17 the pivot pin 18 supports a pair of juxtaposed bearing sleeves 21 which are freely rotatably on the pivot pin. A pair of flat control levers 22 extending in opposite directions at right angles to the pivot pin 18 are welded to the lower portions of respective ones of the bearing sleeves 21 and normally are in a rest position in engagement with the top side of the base plate 15. As is best shown in Fig. 2, each control lever 22 is provided with a recess 22A in the vicinity of the adjacent rocker arm 19. A vertical transverse edge 22B on the control lever, which defines a part of this recess and in the rest position of the control lever is perpendicular to the base plate, is adjacent to one lateral edge 19D of the rocker arm 19 at the corner portion 19C thereof. The gap S separating the transverse edge 22B and the lateral edge 19D of the rocker arm may be one or a few tenths of a millimetre; it is sufficient and suitable for the gap to be just about wide enough to permit unimpeded pivotal movement of the rocker arm 19 until the neighbouring corner portion 19C thereof engages the base plate 15. Near the outer end thereof, each control lever 22 is provided with a laterally projecting arm 22C which coacts with an actuating arm 23A of one of a pair of switches 23 which form a breaker device connected to the control and air supply device 12. Moreover, each control lever 22 is provided with a loading spring 24 which applies a load to the control arm which can be individually adjusted by turning a nut 25. Associated with each control arm is also a stop 26 which limits the pivotal movement of the control arm 22 away from the base plate to a certain angle so that excessive loading of the actuating arm 23A of the associated switch may be avoided. When the pneumatic piston and cylinder assembly 12 is com¬ pletely relieved from load, the rocker arms 19 take a posi- tion within the angular range of pivotal movement which is defined by the base plate 15 and the corner portions 19C of the lower rocker arm end. For convenience of description, the door is assumed initially to be closed and the rocker arms are assumed to be in the centered position shown in Fig. 1. To move the door leaf 14 to open position, the left end of the cylinder of the piston and cylinder assembly 12 is pres¬ surised. When the cylinder is pressurized so that the piston rod is extended, the rocker arms 19 will be pivoted counterclockwise as viewed in Fig. 1. This pivotal movement will not affect the left control lever in any way. On the other hand, after a slight pivotal movement the corner portion 19C of the right- hand lateral edge 19D will engage the vertical transverse edge 22B of the right control lever 22; this engagement occurs before the left corner portion 19C engages the base plate 15. This situation is illustrated in Fig. 3. If the force required to move the door leaf 14 does not exceed a given value determined by the setting of the load spring 24 of the right control lever 22, the rocker arms 19 will not be moved past the position shown in Fig. 3 during the opening movement. Consequently, the right control lever 22 will also remain in its rest position in engagement with the base plate 15. However, if the opening movement of the door leaf 14 should encounter an excessive resistance, caused by an impediment of some kind, the force which the piston and cylinder assembly 12 applies in the counterclockwise direction to the rocker arms 22 will suffice for the force which the right-hand lateral edge 19D of the lower (as viewed in Fig. 2) rocker arm 19 in turn applies to the transverse edge 22B of the right control lever 22 to overcome the load applied by the associated spring 24 and swing this control lever upwardly. The arm 22C of the control lever will therefore operate the actuating arm 23A of the right switch 23. Through the inter- mediary of the control and air supply device 13, this switch 23 will then discontinue the supply of pressurized air to the piston and cylinder assembly 12 so that the piston, and thereby the door leaf 14, will be stopped. If a corresponding excessive loading occurs during the clos¬ ing movement of the door leaf 14, the left control lever 22 in a corresponding manner will be pivotally moved upwardly and act on the associated switch 23 so that that switch causes stopping of the piston and cylinder assembly 12 and the door leaf 14. Because the control levers 22 are constructed as elbow levers having a long lever arm which operates by its outer end the breaker constituted by the switch 23, only a small angular movement of the control levers 22, and thereby of the rocker arms 19, is required for triggering a stopping of the door actuator, that is, of the pneumatic piston and cylinder assembly 12. In the illustrated embodiment, one of the corner portions 19C of each rocker arm 19 together with the adjacent transverse edge 22B of the associated control lever 22 constitutes a freewheel or unidirectional coupling which enables the rocker arm 19 to move in one direction without acting on the associ¬ ated control lever but causes the rocker arm to carry the control lever along when moving in the opposite direction. Although it is preferred to have the separate control levers provided in the exemplary embodiment, it is possible within the scope of the invention to provide a double-acting trip¬ ping function without such separate control levers.

Claims: Claims 1. A safety device for door operating apparatus, com¬ prising a tripping member (19) having connection means (19A) for connecting it to a power operated double-acting door actuator (12) , the tripping member being movable to a tripping posi¬ tion against the action of a predetermined load (24) , and a breaker device (23) for the door actuator (12) , said breaker being operatively connected to the tripping member and adapted in response to movement of the tripping member (19) to the tripping position to operate a control device (13) to cause it to discontinue supply of energy to the door actuator, characterised in that the tripping member (19) is movable against said prede¬ termined load (24) in one direction to a first tripping position and in the opposite direction to a second tripping position, and the breaker device (23) is adapted in both tripping positions to operate the control device (13) to cause it to discontinue supply of energy to the door actuator (12) . 2. A safety device according to claim 1, characterised in that the tripping member is a tripping lever (19) which is mounted for pivotal movement in opposite directions between two stop positions about a stationary pivot member (18) , the connection means (19A) being positioned on the tripping lever at a distance from the axis (18) . 3. A safety device according to claim 2, characterised in that the tripping lever (19) comprises two abutments (19C) which are positioned on opposite sides of a line (L) joining the pivot member (18) and the connection means (19A) and associated with respective ones of the tripping positions, each abutment (19C) engaging a support (15) for the pivot member (18) when the tripping lever (19) is in the associated tripping position. 4. A safety device according to claim 2 or 3 , characterised in that two control levers (22) are pivotally mounted on the pivot member (18) and project in opposite directions from the pivot member, in that the control levers are biassed (24) to respective inactive positions established by the support (15) and independently movable against the bias in opposite directions from the respective inactive positions to respective active positions, in that each con¬ trol lever (22) in the active position thereof operates an associated breaker member (23A) of the breaker device (23) , and in that the tripping lever (19) is connected to the operating lever (22) through respective unidirectional coup¬ lings (19C/22B) . 5. A safety device according to claim 4, characterised in that each control lever (22) is provided with an abutment (22B) which is spaced from the pivot member (18) and in that the tripping lever (19) comprises a pusher portion (19C) which engages the abutment (22B) and carries the control lever along when the tripping lever (19) is pivoted towards one of the tripping positions but goes clear of the abutment (22B) when the tripping lever (19) is pivoted towards the other tripping position. 6. A safety device according to claim 4 or 5, characterised in that each control lever (22) is an elbow lever comprising a short lever arm one end of which is journ¬ alled on the pivot member (18) and the other end of which is joined with a long lever arm, and in that the breaker member (23A) associated with the control lever is positioned in the path of movement of the long lever arm to be operated thereby upon pivotal movement of the tripping lever (19) to the asso¬ ciated tripping position.

Inventors: OEVERSTROEM SVEN-ERIK, OEVERSTROEM, SVEN-ERIK
Applicants: OEVERSTROEM SVEN ERIK, OEVERSTROEM, SVEN-ERIK
Application year: 1996
Main classification: E05F15
IPC codes: E05F15