EP3922799A1

EP3922799A1 - Door actuator

Info

Publication number: EP3922799A1
Application number: EP20179348.6A
Authority: EP
Inventors: Weiming Derek Ho
Original assignee: Dormakaba Deutschland GmbH
Current assignee: Dormakaba Deutschland GmbH
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2021-12-15

Abstract

The present invention concerns a door actuator (1) for opening and/or closing a door (101). The door actuator (1) comprises a housing (2), a damping piston (5) arranged in the housing (2), and a spindle (7) extending through the housing (2). Therein, the spindle (7) is connected to the damping piston (5) such that a rotation of the spindle (7) moves the damping piston (5). Further, at least one telescopic damping spring unit (9) is connected to the damping piston (5) such that the rotation of the spindle (7) and the movement of the damping piston (5) are damped by the telescopic damping spring unit (9). The present invention also concerns a door unit (100) which comprises a door (101) and the door actuator (1).

Description

The present invention relates to a door actuator for opening and/or closing a door and a door unit comprising the door actuator.
Conventionally, cam-type door actuators are known which include damping springs for pressing a damping piston continuously towards the cam surface in order to maintain hydraulic control during all closing situations. These conventional damping springs, however, require a large free space in a housing of the door actuator and thus increase the overall size of the door actuator. In addition, the damping piston, conventionally includes a machined space in which the damping spring is partially arranged. Such damping pistons are, however, complicated and expensive to manufacture and also require additional sealing elements for sealing of the machined space.
An object of the present invention is to provide a door actuator for opening and/or closing a door which has a reduced size and is more cost-effective to manufacture.
This object is solved by the features of the independent claims. The dependent claims contain advantageous embodiments of the present invention.
A door actuator for opening and/or closing a door of the present invention comprises a housing, in which a damping piston is arranged. The door actuator further comprises a spindle which extends through the housing. Therein, the spindle is connected to the damping piston such that a rotation of the spindle moves the damping piston. Furthermore, the spindle comprises a cam surface. The door actuator further comprises one or more telescopic damping spring units connected to the damping piston for pressing the damping piston, especially continuously, towards the cam surface such that hydraulic control is maintained during all closing situations.
The door actuator of the present invention has the advantage that the telescopic damping spring unit may be elastically compressed to a length that is greatly lower than its length in a non-compressed state. Therefore, due to a compact size of the telescopic damping spring unit, a space in the housing for the telescopic damping spring unit may be made smaller, thus saving space and manufacturing costs.
Herein, the telescopic damping spring unit comprises or is an elastic spring element which may contract in a telescopic manner. In other words, the telescopic damping spring unit may consist of or include parts which slide into each other during compression.
Preferably, the telescopic damping spring unit of the door actuator may comprise a conical coil spring. More preferably, the telescopic damping spring unit of the door actuator may comprise multiple conical coil springs. It is thus possible to reduce a space required in the housing for the telescopic damping spring unit and to lower manufacturing costs thereof.
Advantageously, the at least one conical coil spring comprises a number of coils each with a diameter. Further, a compression factor is a quantity determined by dividing a minimum compressed longitudinal length of the conical coil spring by a sum of the diameters of the coils of the conical coil spring. Therein, the compression factor is preferably a maximum of 0.9, even more preferably 0.75, even more preferably 0.5, and/or a minimum of 0.2, preferably 0.3, more preferably one divided by the number of coils. With this, it is possible to further reduce the amount of space required in the housing for the telescopic damping spring and thus lower manufacturing costs thereof.
Further advantageously, the at least one telescopic damping spring unit may comprise sheet metal spirals. It is thus possible to advantageously lower manufacturing costs of the door actuator and preferably increase a damping force of the telescopic damping spring unit while reducing the amount of space required in the housing therefor.
Preferably, a free length of the telescopic damping spring unit in a pre-installed state is 10 mm to 50 mm, even more preferably 20 mm to 40 mm. This has the advantage that the amount of space required therefor may be reduced while simultaneously attaining a suitable damping force of the telescopic damping spring unit.
Advantageously, the telescopic damping spring unit of the door actuator abuts an outermost surface of the damping piston and a damping portion inner wall of the housing. This has the advantage that no machining of the damping piston is required for holding the telescopic damping spring unit, thereby further reducing the manufacturing costs of the door actuator.
The damping piston may further comprise a first roller which rolls on the cam surface of the spindle such that the rotation of the spindle is translated into a longitudinal movement of the damping piston. It is thus possible to provide a compact means for translating the movement of the damping piston into a rotation of the spindle, thereby further reducing the size of the housing and lowering manufacturing costs therefor.
Further preferably, the door actuator includes a closer piston and a closer spring in the housing. Therein, a movement of the closer piston caused by the closer spring rotates the spindle for opening and/or closing of the door. It is thus possible to provide a door actuator with an advantageously reduced overall size. In addition, since the rotation of the spindle is coupled with the damping piston, said rotation is damped by the damping piston.
Further advantageously, the closer piston comprises a second roller which rolls on the cam surface of the spindle. Therein, a longitudinal movement of the closer piston is translated into a rotational movement of the spindle via the interaction between the second roller and the cam surface of the spindle. This further advantageously reduces the amount of space required in the housing for the closer piston and closer spring, thereby also reducing the manufacturing costs therefor.
Preferably, the closer piston and the damping piston are arranged along the same longitudinal axis, wherein the longitudinal axis is perpendicular to a rotation axis of the spindle. It is thus possible to provide a door actuator with a further reduced overall size, thereby also further advantageously reducing the manufacturing costs therefor.
Advantageously, a longitudinal axis of the closer spring and a longitudinal axis of the telescopic damping spring unit may overlap with each other in a coaxial arrangement. This has the advantage that the overall size of the door actuator, especially in a direction parallel to the rotation axis of the spindle, may be advantageously reduced.
In a preferred configuration, a longitudinal axis of the closer spring and a longitudinal axis of the telescopic damping spring unit are parallel to each other and/or parallel to the longitudinal axis. With such an alignment of the closer spring and the telescopic damping spring unit, it is further possible to advantageously reduce the overall size of the door actuator, especially in a direction perpendicular to the rotation axis of the spindle, and thereby also reduce the manufacturing costs therefor.
The present invention also concerns a door unit comprising a door and the door actuator according to any of the foregoing preferred configurations. Therein, the spindle is drivingly connected to the door or to a rod assembly, wherein the rod assembly is further connected to a door frame. Therefore, a rotation of the spindle opens or closes the door and the damping piston damps the opening and/or closing movement of the door.
This has the advantage that a door unit can be provided, wherein the door actuator thereof may be advantageously manufactured with low costs and with a low overall size, thus also reducing a necessary installation space for the door actuator of the door unit.
Further details, advantages, and features of preferred embodiments of the present invention are described in detail with reference to the figures. Therein,

Fig. 1 shows a schematic cross section of a door actuator according to a first embodiment of the present invention,
Fig. 2 shows a schematic cross section of a door actuator according to a second embodiment of the present invention,
Fig. 3 shows a detailed side view of an element of the door actuator according to the embodiments of the present invention,
Fig. 4 shows a detailed side view of an element of the door actuator according to the embodiments of the present invention, and
Fig. 5 shows a schematic drawing of a door unit of the present invention.

Fig. 1 shows a schematic cross section of a door actuator 1 according to a first embodiment of the present invention.
The door actuator 1 includes a housing 2 which comprises a damping section 4 and a closer section 3. A closer spring 14 is provided in the closer section 3 of the housing 2. The closer spring 14 is interposed between an inner side wall of the housing 2 and a closer piston 6. Therein, a compression and/or decompression of the closer spring 14 causes a longitudinal movement of the closer piston 6 in the closer section 3 of the housing 2.
Further, the door actuator 1 comprises a telescopic damping spring unit 9 in the damping section 4 of the housing 2. Therein, the telescopic damping spring unit 9 is interposed between an inner wall 11 of the housing 2 and an outermost surface 10 of the damping piston 5. Thus, a compression telescopic damping spring unit 9 presses the damping piston 5 in the damping section 4 to the right of the housing 2. The telescopic damping spring unit 9 comprises or is an elastic spring element which may contract in a telescopic manner. In other words, the telescopic damping spring unit 9 may consist of or include parts which slide into each other during compression.
Therein, the telescopic damping spring unit 9 is a conical coil spring (compare Fig. 3). In this case, coils of the conical coil spring 9 slide into each other during compression, thus reducing the amount of space necessary for housing the telescopic damping spring unit 9 between the inner wall 11 of the housing 2 and the damping piston 5. In this embodiment, the telescopic damping spring unit 9 and the closer spring 14 are arranged along a longitudinal axis 15 extending through the housing 2. More specifically, a longitudinal axis 17 of the closer spring 14 and a longitudinal axis 18 of the telescopic damping spring unit 9 overlap with each other as well as with the longitudinal axis 15 extending through the housing 2.
Further, the door actuator 1 includes a spindle 7 which extends through the housing 2. The spindle 7 further comprises a cam surface 12. In addition, the damping piston 5 comprises a first roller 13 which rolls on the cam surface 12. The closer piston 6 comprises a second roller 19 which also rolls on the cam surface 12. Therefore, when either of the damping piston 5 or the closer piston 6 are moved in a direction along the longitudinal axis 15, the spindle 7 is rotated via the interaction between the first roller 13 and/or the second roller 19 and the cam surface 12 of the spindle 7. Herein, an axis of rotation 16 of the spindle 7 is perpendicular to the longitudinal axis 15.
More specifically, the closer spring 14 exerts a force in the longitudinal axis 15 direction for moving the closer piston 6. The closer piston 6 in turn rotates the spindle 7 via the second roller 19 and the cam surface 12. A rotation of the spindle 7 exerts a force in the longitudinal axis 15 direction onto the damping piston 5 via the cam surface 12 and the first roller 13, thus compressing the telescopic damping spring unit 9.
Fig. 2 shows a schematic cross section of a door actuator 1 according to a second embodiment of the present invention. More specifically, Fig. 2 shows a detailed view of the damping section 4 of the door actuator 1 according to the second embodiment of the present invention.
In this embodiment, the door actuator 1 includes a plurality of, especially two, telescopic damping spring units 9. Therein, the longitudinal axis 18 of each of the telescopic damping spring units 9 is parallel to the longitudinal axis 17 of the closer spring 14 and the longitudinal axis 15 extending through the housing 2. This has the advantage that a size of the housing 2 in the longitudinal direction 15 may be reduced, while increasing the number of telescopic damping spring units 9 for upholding a necessary force exerted by the telescopic spring units 9.
Figs. 3 and 4 each show detailed side views of an element of the door actuator 1 according to the embodiments of the present invention. More specifically, Figs. 3 and 4 each show examples for a telescopic damping spring unit 9 of the door actuator 1 in a state before being installed in the door actuator 1.
As shown in Fig. 3, the telescopic damping spring unit 9 of the door actuator 1 may be a conical coil spring 9 which comprises a plurality of wire coils or spirals. As shown in Fig. 4, the telescopic damping spring unit 9 of the door actuator 1 may include a plurality of coils or spirals at least partially comprising sheet metal. In both cases, the coils of the telescopic damping spring unit 9 each have a predetermined diameter 20. In the case of the telescopic damping spring unit 9 comprising coils of sheet metal, the diameter of each of the coils is defined as a height of each coil along the longitudinal axis 18 of the telescopic damping spring unit 9.
The conical coil spring 9 of the embodiments has a free length of 26 mm and a coil diameter 20 of 2.5 mm. In addition, the conical coil spring 9 has a length of 17.5 mm at a load of 94 N. Further, an example for a compression factor of the telescopic damping spring unit 9 will be explained with reference to the conical coil spring 9 of Figs. 1 and 3.
The compression factor of a conical coil spring 9 is calculated by dividing a minimum elastically compressed length 21 (compare Fig. 1) by a sum of all diameters 20 of the coils. For example, a telescopic damping spring unit 9 generally has a compression factor of less than 1. As can be taken from Fig. 3, the conical coil spring 9 has a total of 4.5 coils. In the embodiment shown in Figs. 1 and 3, the compression factor of the conical spring 9 is roughly 0.4 to 0.6.
Fig. 5 shows a schematic drawing of a door unit 100 of the present invention.
The door unit 100 comprises a door 101 and the door actuator 1 according to the foregoing embodiments. Further, the spindle 7 of the door actuator 1 is connected to the door 101 for opening and/or closing thereof. More specifically, the spindle 7 of the door actuator 1 is connected to a rod assembly 102 which is connected to a door frame 103. Therefore, a rotation of the spindle 7 opens or closes the door 101.
In addition, the opening and/or closing movements of the door 101 are damped by the damping piston 5 of the door actuator 1. Thus, the telescopic damping spring unit 9 may prevent the damping piston 6 from losing contact with the cam surface 12 and thus losing hydraulic control of the movement of the door 101.

List of Reference Numerals

1 door actuator
2 housing
3 closer section of housing
4 damping section of housing
5 damping piston
6 closer piston
7 spindle
9 telescopic damping spring unit
10 outermost surface of the damping piston
11 inner wall of the housing
12 cam surface
13 first roller
14 closer spring
15 longitudinal axis
16 rotational axis of the spindle
17 longitudinal axis of the closer spring
18 longitudinal axis of the telescopic damping spring unit
19 second roller
20 diameter of spring coils
21 minimum compressed longitudinal length of the telescopic damping spring unit
100 door unit
101 door
102 rod assembly
103 doorframe

Claims

A door actuator (1) for opening and/or closing a door (101), comprising:
• a housing (2);

• a damping piston (5) arranged in the housing (2);

• a spindle (7) extending through the housing (2), wherein the spindle (7) is connected to the damping piston (5) such that a rotation of the spindle (7) moves the damping piston (5), wherein the spindle (7) comprises a cam surface (12) and

• at least one telescopic damping spring unit (9) connected to the damping piston (5) such that the damping piston (5) is pressed towards the cam surface (12) by the telescopic damping spring unit (9).
Door actuator (1) according to claim 1, wherein the telescopic damping spring unit (9) comprises at least one conical coil spring.
Door actuator (1) according to claim 2, wherein the at least one conical coil spring comprises a number of coils each with a diameter (20), wherein a compression factor is given by a minimum compressed longitudinal length (21) of the conical coil spring divided by a sum of the diameters (20) of the coils, and wherein the compression factor of the conical coil spring is a maximum of 0.9, preferably 0.75, more preferably 0.5, and/or a minimum of 0.2, preferably 0.3, more preferably one divided by the number of coils.
Door actuator (1) according to any one of claims 1 to 3, wherein the telescopic damping spring unit (9) comprises sheet metal spirals.
Door actuator (1) according to any one of claims 1 to 4, wherein a free length of the telescopic damping spring unit (9) in a pre-installed state is 10 mm to 50 mm, preferably 20 mm to 40 mm.
Door actuator (1) according to any one of claims 1 to 5, wherein the telescopic damping spring unit (9) abuts an outermost surface (10) of the damping piston (5) and a damping portion inner wall (11) of the housing (2).
Door actuator (1) according to any one of claims 1 to 6, wherein the damping piston (5) comprises a first roller (13) rolling on the cam surface (12) such that the rotation of the spindle (7) is translated into a longitudinal movement of the damping piston (5).
Door actuator (1) according to any one of claims 1 to 7, further including a closer piston (6) and a closer spring (14) in the housing (2), wherein a movement of the closer piston (6) caused by the closer spring (14) rotates the spindle (7) for opening and/or closing of the door (101).
Door actuator (1) according to claim 8, wherein the closer piston (6) comprises a second roller (19) rolling on the cam surface (12) such that a longitudinal movement of the closer piston (6) is translated into a rotational movement of the spindle (7).
Door actuator (1) according to claims 8 or 9, wherein the closer piston (6) and the damping piston (5) are arranged along the same longitudinal axis (15), and wherein the longitudinal axis (15) is perpendicular to a rotation axis (16) of the spindle (7).
Door actuator (1) according to any one of claims 8 to 10, wherein a longitudinal axis (17) of the closer spring (14) and a longitudinal axis (18) of the telescopic damping spring unit (9) are parallel to each other and/or parallel to the longitudinal axis (15).
A door unit (100), comprising:
• a door (101); and

• the door actuator (1) according to any one of claims 1 to 11, wherein the spindle (7) is drivingly connected to the door (101) or to a rod assembly (102) connected to a door frame (103) such that a rotation of the spindle (7) opens or closes the door (101) and the damping piston (6) damps the opening and/or closing movement of the door (101).