EP0500984A1 - Drive unit with four limit switches - Google Patents

Abstract

In order to drive gates, in addition to the elements which carry out the work, such as circulating chains etc., electrical drive units are known in which an electric motor, a transmission unit and further control elements are accommodated inside a housing which consists of a baseplate and housing and is screwed to the cover etc.. In this case, it is also known for the limit switches, for the approach to the limit positions of the gate, to be accommodated inside the housing. In order additionally to define points at which the moving door actually changes over from high speed to slow speed, time-dependent controllers were used in the past. In order to increase the adjustment capability and the ease of repair, it is intended to implement all four positions by electromechanical limit switches. To this end, in addition to the previously known two limit switches which were mounted on the baseplate (1) in addition to longitudinally moving control elements, two such limit switches are also accommodated in a suitable depression (27) in the baseplate (1) under the control elements and are held in position by retaining parts which are mounted and screwed on with the aid of the two other limit switches. <IMAGE>

Description

To automatically open gates, the corresponding electric drive units must be installed at a different location depending on the function of the gate and connected to the gate with special connecting elements.

In the case of a gate swinging upwards, it is known, for example, to mount a guide rail in the area of the ceiling, in which a drive chain or a similar means rotates, and to move a carriage along this guide rail. This slide is connected to the door leaf via a guide rod, which means that it can be opened and closed. Usually the end of the chain facing away from the gate is driven with the aid of the deflection pinion by an electric drive unit which is attached to the ceiling. In order to stop the movement of the chain and thus the gate in the correct end positions, limit switches or other elements with the same effect are necessary.

The limit switches can either be arranged in the area of the gate and actuated directly by it, or can be provided within a protected housing on the drive unit.

In the former case, the adjustment work to achieve the correct end positions of the door is easy to carry out, but there is an increased risk of damage to these limit switches, and cables must also be laid from the limit switches to the drive unit.

In the second case, the limit switches are protected from damage and dirt in the housing of the drive unit, but must be set precisely so that their triggering actually corresponds to the desired end positions of the door to be moved.

The second solution corresponds, for example, to the subject matter of European patent application EP 8812121. The entire drive unit is accommodated in a housing which consists of a base plate and a cover. The base plate is screwed to the ceiling and has integrally formed with the base plate spacers, so that the chain drive pinion including the rail in which the chain rotates is housed in the distance between the base plate and the ceiling.

On the side of the base plate facing away from the ceiling, all elements of the drive unit are mounted, for example an electric motor-gear unit, the output shaft of which extends through an opening in the base plate out of the housing, i.e. in the direction of the ceiling of the building, and with the sprocket driving the chain is connected.

Even within the housing, the rotary motion of the drive shaft is transmitted to a threaded spindle mounted parallel to the base plate, on which there are nuts as cams that are prevented from rotating with the threaded spindle. As a result, these nuts are screwed together when the gate is driven along the threaded spindle, so that after the nuts on the threaded spindle have been set once, a specific axial position on the threaded spindle can be assigned to a specific position of the gate.

The nuts on the threaded spindle are prevented from rotating by an angle screwed onto the base plate next to the threaded spindle, one leg of which is located directly next to the nuts. Through elongated holes in the angle transverse to the longitudinal direction of the threaded spindle, it can be brought into contact with the nuts and adjusted without any problems.

On the side of the threaded spindle opposite the angle, two known, electromechanical limit switches are screwed to the base plate, the buttons of which are actuated by the nuts moving along the threaded rod, one of which corresponds to the open and the other to the closed position of the gate.

In addition, it is known to use control electronics instead of limit switches, which are switched by mechanical elements that move depending on the gate, which is programmed, for example, for a certain operating time, which is used to move the gate from the fully open to the fully closed position and vice versa is necessary.

The use of such electronic controls has not only proven to be more expensive but also more prone to failure: on the one hand, the drive unit's time required to move the door from one setting to the other is not always the same, but depends, among other things. from the operating temperature of the drive unit, that is to say, for example, the ambient temperature, and also from its frictional losses, which can increase with increasing contamination, damage, etc. Fluctuations in the mains voltage are also responsible for a different operating time.

It should be noted that an incorrect operating time of just 1 or 2% can lead to a door that is opened a few cm instead of completely closed, or if the drive unit continues to run after only a few seconds, the drive motor is damaged by only a few seconds can lead.

In addition, a mechanical solution is much simpler in terms of adjustability, which is desirable for people with different qualifications who have to carry out the installation and initial adjustment or readjustment.

In particular, a different result between the setting attempts and the practical operation can be attributed to the fact that the door is opened and closed many times in succession during the setting process, as a result of which the electric motor, the chain, etc. are in the optimal thermal operating state. In practice, the drive unit on the other hand, often only operated at 12-hour intervals and is therefore much colder, especially in winter. In practice, a very precise setting with repeated attempts does not lead to the desired result of full opening and, above all, complete closing of the gate.

Furthermore, it is known in such gate drives not to move the gate to its end position at the same speed, but to reduce the operating speed shortly before this setting is reached, in order to avoid damage by the relatively large mass of the gate at too high a speed reached the end position and thus an attachment to a mechanical resistance.

Since the time between reaching the point at which the speed is to be reduced and reaching the end position is telatively short compared to the entire duration of the operating process, time-dependent circuits can be used somewhat better for this phase, since with a certain one percentage deviation of the time setpoint, the absolute time difference is relatively small.

For this reason, the combination of two electromechanical limit switches within the housing of the drive unit with a time-dependent electronic control for determining the time period for the slow phase is known.

But even in this case there is the difficulty that such a time-dependent control always appears to the assembler or adjuster as a "black box" and is difficult to correct if the operating result is incorrect, since this is always only possible by adjusting the electromechanical limit switches. If the electronic time unit itself delivers a wrong result, it cannot be adjusted, but can only be exchanged, which is not only associated with costs but also usually with a longer loss of use.

For this reason, it is desirable to completely dispense with electronic control in the drive unit, and to effect both the setting of the gate and the start of the slow-running phase by means of mechanically switched limit switches.

Since the rotational movement of the threaded spindle is removed from the output shaft of the motor-gear unit where it leaves the housing, there is very limited space on the threaded spindle, since a purchased part is used as the motor-gear unit and thus between the base plate and the existing distance to the motor body is already fixed. An additional increase in this distance is also not desirable, since this would increase the overall height of the drive unit, which complicates the assembly at certain installation locations, such as at a lintel of a door, i.e. between the upper edge of the door cavity and the slightly higher ceiling or would make impossible.

On the other hand, the threaded spindle cannot be made long enough to arrange all limit switches on the same side of the threaded spindle, as in the previously known solution, even with four limit switches.

If, on the other hand, two of the four desired limit switches are attacked from the underside of the base plate, that is to say from above in the assembled state, the distance between the base plate and the ceiling can be used to accommodate two limit switches. A prerequisite for this, however, is that the pinion which is attached to the output shaft and which drives the chain has such a small diameter that the chain does not protrude into the area in which the limit switches are located have to. This is possible if the speed of rotation of the motor or the reduction of the downstream gear unit is coordinated with a view to the smallest possible pinion.

The advantage of accommodating the two limit switches acting from below is not only that no additional space is required on the upper side of the base plate, but also that the pockets formed in the base plate additionally serve to stiffen the base plate to accommodate these limit switches. The stiffening ribs, which are necessary anyway, are therefore only brought into such a position that they - together with a lower enclosure of the limit switches to increase the stability of these ribs - form a lateral guide for the limit switches.

For the production of such base plates in the injection molding process, it is also advantageous if the limit switches are not seated directly on the bottom of the pockets, since irregularities can arise here due to inaccuracy of the injection molding process. For this reason, these pockets are made deeper, but have corresponding heels in the area in which the limit switches are seated.

For reasons of manufacturability, it is further advantageous to combine these two pockets into a common depression, the positioning of each individual limit switch being in turn precisely defined by corresponding paragraphs. This recess should be open at least on one of its end faces, which makes the manufacturing process easier.

These limit switches acting from below are not held in position by screwing but held from above by appropriate molded parts in contact with the circumferential surfaces of the pockets, spring plates preferably being used as holding parts which, when the other limit switches are screwed onto the base plate, between these limit switches and Base plate are laid and fixed with this. This also speeds up and makes the assembly process cheaper.

In order to be able to determine the actuation time of the pushbuttons of the limit switches as precisely as possible, the previously known commercially available hexagon nuts on the threaded spindle are not used as cams, since these have excessive manufacturing inaccuracies in addition to the rounded edges. Instead, specially designed plastic nuts are used, which not only have an exactly right-angled leading edge, but also regularly have slots arranged in the longitudinal direction distributed over the circumference, in which a corresponding extension of the fixing angle screwed on next to the threaded spindle engages to prevent rotation. Since due to its elongated holes this angle can be varied continuously in its distance from the threaded spindle, it is possible to let the extension protrude only so far into the slots of the nuts that it does not reach the bottom thereof. This results in a significantly lower sliding friction between the nuts and the guide bracket than when one of the brackets of the bracket is in full contact on one side of a hexagon nut.

If, on the other hand, it is not possible for certain reasons, for example a necessary enlargement of the chain sprocket or the like, to accommodate the two limit switches below the threaded spindle, two of the limit switches can be screwed onto the base plate on both sides of the threaded spindle. The anti-rotation device for the nuts running on the threaded rod must then be arranged above or below the threaded spindle. A particularly simple solution is the insertion of an appropriately dimensioned rod through the bearing blocks of the threaded spindle at such a distance from the threaded spindle that this rod comes to rest in the slots in the nut. Since the threaded spindle ends near the outer edge of the base plate, such a rod can be easily pulled out of the bearing blocks of the threaded spindle after the cover has been removed from the base plate.

By cranking this rod at the end adjacent to the edge of the base plate, it is prevented that the rod moves too far inwards and is no longer held by both bearing blocks. An automatic removal is also not possible, as this is prevented by the cover attached.

Fig. 1

eine Querschnittsdarstellung durch eine an der Decke montierte Antriebseinheit,

Fig. 2

eine teilweise Aufsicht auf die Grundplatte bei montierten Endschaltern,

Fig. 3

eine Aufsicht ähnlich der Fig. 2 auf eine leere Grundplatte,

Fig. 4

eine Schnittdarstellung der Vertiefung für die Endschalter,

Fig. 5

eine Schnittdarstellung rechtwinklig zur Darstellung der Fig. 4,

Fig. 6a,b

eine Darstellung der Mutter und

Fig. 7a,b,c,d

eine Darstellung des Verriegelungswinkels.

An embodiment according to the invention is described in more detail with reference to the figure description. Show it:

Fig. 1

2 shows a cross-sectional representation through a drive unit mounted on the ceiling,

Fig. 2

a partial view of the base plate with the limit switches installed,

Fig. 3

2 shows a top view similar to FIG. 2 on an empty base plate,

Fig. 4

a sectional view of the recess for the limit switch,

Fig. 5

4 shows a sectional illustration at right angles to the illustration in FIG. 4,

6a, b

a representation of the mother and

7a, b, c, d

a representation of the locking angle.

1 shows a drive unit 20 mounted on the ceiling with a base plate 1 to which all components of the drive unit 20 are fastened and which is screwed tightly to the ceiling.

The cover 2 placed on the base plate 1 serves to protect these components from damage and contamination. The minimum distance A between the base plate and the ceiling, which is determined by the spacers formed in one piece with the base plate 1, depends on the overall height of the pinion 7, the chain 18 driven thereby and the rail receiving this, which must find space between the base plate and the ceiling.

The motor-gear unit 3 is screwed to the base plate 1 by means of its feet 4, the output shaft 5 extending through the opening 6 of the base plate into the space between the base plate 1 and the ceiling of the building and being connected there to the pinion 7 .

The output shaft 5 is also connected to the coaxial socket 12 in a rotationally fixed manner by means of notched nails 26, so that the bevel gear teeth 13 of this socket 12 are located inside the housing, that is to say on the cover-side side of the base plate 1, and their rotation there on the bevel gear 14, which is on one end of the threaded spindle 9 sits, can transmit. The bevel pinion 14 and partly also the threaded spindle 9 are still below the motor-gear unit, for which the maximum distance F between the base plate and the motor-gear unit 4 is available, which is determined by the dimensions of this purchased part.

Above all, the overall height of this motor-gear unit 3 also determines the clear height B of the cover 2, which results in the total height C of the drive unit 20.

In the assembled state of FIG. 1 there are two limit switches 8 above the threaded spindle 9, which has a total of 4 nuts 10, and also in corresponding pockets 21 of a common recess 27 under the threaded rod, in which they are held by a spring plate 22 (in Fig. 1 not shown).

As can be seen better in the top view of FIG. 2, the two upper limit switches 8 are located next to the threaded spindle 9, where they are screwed directly onto the base plate. The arm-like button of each limit switch ventilates slightly at an angle to the threaded rod and can be rotated about a vertical pivot axis 50 in the limit switch. The Limit switches are already fixed in their position for screwing by stops 29 projecting vertically from the base plate, a spring plate 22 additionally being placed between these limit switches 8 and the base plate 1 before screwing and being clamped during screwing, which enables the positioning of the screw below the threaded spindle 9 horizontal limit switch 8 is used.

Fig. 2 also shows the position of the angle 16 which is screwed to the base plate on the free side of the threaded spindle 9.

With the help of the elongated holes 17 in the leg of the angle 16 resting on the base plate 1, the latter can be pushed so far onto the threaded spindle 9 before the screws 30 are tightened that the longitudinal projection 23, which extends from the leg striving perpendicularly from the base plate 1 in the direction protrudes on the threaded rod 9, engages in the slots 24 of the nuts 10 in the desired manner.

It is intended that this projection 23 does not reach the bottom of the slots 24 as far as possible, but only touches the inner contour of the slots 24 on its side surfaces in order to keep the friction between nuts 10 and angle 16 and thus the effort as low as possible.

Each of the nuts 10 represents either one of the end positions of the door to be moved, or one of the points at which a switch from high speed to slow speed is carried out before the end position is reached.

In this way, one of the nuts 10 switches one of the limit switches 8 in each case. In order to avoid mutual hindrances, for example switching on a limit switch by the wrong nut 10, nuts 10 of different sizes can be used. For example, the nuts 10 located on the outside of the threaded spindle 9 can have a smaller diameter than the nuts located on the inside, in order to be able to switch only the limit switch assigned to them and to be able to run over the button located further inside without contact.

As best shown in FIGS. 6a and 6b, the nuts 10 are preferably plastic cylinders with relatively weakly rounded outer edges and a coaxial threaded bore 33 matched to the threaded spindle 9. A defined design of the outer edges 35 is necessary since this is the control edges for the push buttons 36 are the limit switches 8. When using nuts 10 with different outer diameters, the depth of the slots 24 must also be different, since the distance 34 of the bottom of the slots 24 from the center of the nut 10 must be the same, since the same projection 23 of the angle 16 approximately this bottom of the slots 24 must reach. When the nuts 10 are made from polyamide, the contact depth between the projection 23 and the inner surface of the slots 24 should be approximately 2 mm in depth, on the one hand to achieve a sufficiently secure blocking of the nuts and on the other hand to minimize the friction with respect to the angle 16.

As shown in FIG. 7, the angle 16 consists, in a manner known per se, of a leg resting on the base plate, in which two oblong holes 17 are arranged transversely to the longitudinal direction of the angle 16 for screwing to the base plate 1. The other leg 37 projects from this leg at a right angle, the stability of which is ensured by triangular struts 38 to the other leg.

From this leg 37 protrudes from the side opposite the adjacent leg of the projection 23, which extends over the entire length of the angle 16, at such a height that it is in the assembled state of the angle 16 at the level of the axis of rotation of the threaded rod 9 comes to rest. The projection 23 is rounded at the free end.

Fig. 3 shows a partial plan view of the base plate similar to Fig. 2, but without components attached to it.

Between the bearing blocks 15, in which the threaded rod 9 is guided, the recess 27 can be seen, which in their End regions is expanded and forms the pockets 21 for receiving the two limit switches located under the threaded rod 9 by the resulting paragraphs 32.

As can be seen better in the cross-sectional illustration of FIG. 5, the depression 27 is formed by side walls 41 which are formed in one piece with the base plate 1 and are connected to one another at the bottom of the depression via a base 42 to increase the stability.

Since inaccuracies can occur precisely in the area of the bottom of such depressions during manufacture, the limit switches do not sit on this floor, but rather somewhat higher on corresponding shoulders 32 which run along the side walls 41 in such a length as corresponds to the size of the limit switches 8. The recess 27 has an end wall 43 on one side, which is connected to the bottom 42 and the side walls 41. This end wall 43 is located in the vicinity of the outer wall 44 of the base plate. The opposite end face of the recess 27 is largely open in order to make it easier to manufacture the base plate and to be able to lead cables underneath the base plate to the pockets 21.

5 shows, the side walls 41 are rounded on one side and obliquely on the other side into the base plate 1 in order to make it easy to insert the limit switches. 5 also shows the stops 29 projecting vertically upward from the base plate, between which the limit switches 8 screwed onto the base plate are placed for the purpose of assembly. Furthermore, the raised contact surface 28 can be seen in FIG. 5 and also in FIG. 3 in the area of each of these two limit switches 28. As a result, a defined height of the limit switches 8 screwed onto the base plate is achieved with respect to the threaded rod 9, even if the rest of the top side of the base plate has some slight warping due to the manufacturing process. The thread length in the screwing points 39 is also increased as a result. On this support surface 28, a spring plate 22 with a corresponding shape is placed in such a way that it follows the horizontal course of the contact surface 28 and its rounded transition into the recess 27 and ends there horizontally after a right-angled bend. This free end 46 presses when the limit switch 8 is inserted on its upper side, so that the spring plate no longer abuts the curve, as shown in FIG. 5.

4 shows a limit switch 8 in a pocket 21.

On the side of the recess 27 opposite the upper limit switches, at the upper edge of the edge of the recess 27 chamfered there runs a stop edge 47 striving from the upper side of the base plate, which serves to adjust the angle 16 before adjusting and screwing it down.

Claims (11)

Drive unit (20) for automatically opening gates, - which is mounted in a housing consisting of base plate (1) and cover (2), - With an electric motor-gear unit (3) which is fixed within the housing on the base plate (1) and its output shaft (5) extends through an opening (6) in the housing to the outside, where it with a transmission element for moving the gate is connected and - With at least two electromechanical limit switches (8) within the housing for switching the drive unit (20),
characterized in that - There are at least four limit switches (8) for reducing the drive speed in the vicinity of the end positions of the door and switching off at the end positions. Drive unit according to claim 1, - The base plate (1) is fastened at a distance from the wall or ceiling of the building by means of spacers integrally connected thereto and the cover (2) is placed on the side of the base plate (1) facing away from the ceiling, a threaded rod (9) mounted parallel to the base plate (1) is rotated by the output shaft (5) within the housing, and the limit switches (8) are switched by contact with elements which are screwed onto the threaded rod (9) and do not rotate but are axially movable,
characterized in that
Hold two limit switches (8) on the threaded rod (9) from the same side. Drive unit according to claim 1 or 2
characterized in that
two of the limit switches (8) on the same side next to the threaded rod (9) are screwed onto the base plate (1) and two of the limit switches (8) are directed against the threaded rod (9) from below. Drive unit according to one of the preceding claims
characterized in that
the limit switches (8) acting from below sit in precisely fitting pockets (21) of the base plate (1) which are open towards the threaded rod (9) and are held in the pockets (21) from above by a holding part. Drive unit according to claim 3 or 4,
characterized in that
at least one spring plate (22) serves as a holding part, which is screwed between the two limit switches (8) screwed onto the base plate and the base plate (1). Drive unit according to one of the preceding claims,
characterized in that - The axially movable elements are nuts, in particular made of plastic, which have slots (25) on the circumference at regular intervals over the entire length and are prevented by an angle (16) from rotating with the threaded spindle (9), which is parallel to the threaded spindle (9) is screwed onto the base plate and has a projection (23) directed against the threaded spindle (9) over its entire length, which fits into the slots (25) of the nuts, - Wherein the angle lying on the base plate (1) transverse to the longitudinal direction of the threaded spindle (9) has elongated holes. Drive unit according to one of claims 4 to 6,
characterized in that
the two pockets (21) form a common depression (27), lden, which is closed to the lower edge of the base plate (1), that is to say to the ceiling or wall, and in the areas in which the limit switches are to be seated are widened to form pockets (21). Drive unit according to one of claims 4 to 6,
characterized in that
the recess (27) is open on at least one end face. Drive unit according to claim 1 or 2,
characterized in that
Two limit switches (8) are screwed onto the base plate (1) on both sides of the threaded spindle (9). Drive unit according to claim 9,
characterized in that
As an anti-rotation device for the axially displaceable elements, an elongated element is pushed parallel or parallel to the threaded rod (9) above or below through the bearing blocks, so that it comes to rest in the slots (25) of the nuts (10). Drive unit according to one of the preceding claims,
characterized in that
the contact surface (28) for the limit switches (8) on the base plate (1) in the area of the limit switches is partially increased and the base plate upright stops (29) are held in position vertically next to the limit switches.

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