EP1035268B1 - Motor-driven staircase - Google Patents

Abstract

The two or more connected sets of steps are driven by a motor with gearing wherein the upper step part in the useful state forms the drive member and the lowermost part in the useful state forms the coupling member. An intermediate link member forms the output member. The articulated gearing means that the unfolding and collapsing of the middle and lower step parts are coupled together. A crank fixed directly or indirectly to the upper step in the useful state prevents excessive strain in the gearing and motor.

Description

The present invention relates to motorized folding staircases which are often used as access to attics or false ceilings.

Floor stairs are usually used to reach attics, flat roofs or other structures. The known floor stairs are provided with a hatch cover and foldable, retractable or collapsible, so that they can be stowed in a hatch frame. Depending on the design, the floor stairs can be divided into three groups: scissor stairs, retractable stairs and foldable stairs. The three-part foldable staircases are most commonly used because of their simple construction and the associated low production costs and their small footprint. But a motor-driven three-piece folding staircase is not known to me.

For scissor stairs and retractable stairs, there are some suggestions for motor drive, z. B. DE-A 2458788, DE-A 1509491, DE-A 1905220, DE-GM 9214710 and DE-A 4325366. Due to the relatively complicated construction and the associated higher production costs both with regard to the stairs seihst as well as in the However, such stairs are usually expensive in terms of their motor drive.

The main problem with motor-driven foldable stairs is in coupling the movements of two hinged stair parts in such a way that both the use and the stowage of the stairs are guaranteed.

Another problem is the heavy use of the gearbox and motor when the staircase is loaded during use or when the stairs extend to their use position. This problem exists because the motor drive is intended only for the opening and stowing of the stairs and the load must be carried by the staircase construction itself during use. If the motor is switched off too early during operation, the stairs will not yet be in their position Used condition and the stairs can carry no load. Use of the stairs in this state leads, alone to the load on the gearbox and the engine, which is not provided. If the motor is switched off too late during operation, the transmission and the motor are subjected to a high level of stress due to the sudden blocking of the unfolding or extension of the staircase.

For motorized three-part folding staircases a simple coupling of the opening of the hatch cover with the unfolding of the stairs must be found, the unfolding of the stair parts only after the hatch cover is opened and the closing of the hatch cover only after the folding of the stair parts begins.

Accordingly, it is an object of this invention to develop a simple transmission for coupling two hinged together stair parts.

Another object of this invention is to develop constructions to avoid high stress on the gearbox and engine during use of the staircase or during the extension of the staircase to its position of use.

Another object of this invention is to develop a transmission for the coupling of the opening of the hatch cover with the deployment or extension of the stairs, wherein the unfolding of the stair parts only after the hatch cover is opened and the closing of the hatch cover only after the folding of the Stair parts begins.

The o. G. Problems or tasks are solved or overcome in the invention with the following measures:

The invention relates to a motor-driven folding staircase with a four-bar linkage for coupling two hinged stair parts. The stairs in the use state upper stair part is the drive member in the four-bar linkage, in the stairs Gebranchszustand lower stair part of the coupling member, the false ceiling or the fitting attached thereto or the top of the staircase usually attached to the hatch cover or the fitting attached thereto, the frame and a two-link member the output member. The output member can be constructed as a handrail of the stairs, as shown in one embodiment.

To stow the stair parts as compatible as possible, an additional joint or several additional joints in the o. G. Vicrgelenlcgetriebe be used. Before the stair parts unfold to their use state, all relative movements in the additional joints must be prevented, so that the four-bar linkage is created and the staircase parts can be brought into their state of use.

For two-part foldable stairs for false ceilings or galleries in the invention, a construction is presented in which no stress during use of the stairs or no high stress occurs during the extension of the stairs in the gearbox and in the engine. The design is a crank with a guideway on which the linear motor or equivalent drive directly drives by means of a pin. The guideway is constructed so that the pin is not normally in the state of use of the stairs at the end of the guideway. This ensures that no or no higher stress in the transmission and the engine occurs and that the ceiling height can be adjusted by changing the stairs slope.

• einer Führung, vorzugsweise einer Linearführung, die auf dem obersten Treppenteil oder auf dem Lukendeckel befestigt ist;
• einem Gleitstein, der an eines Führung angeordnet ist und mit den Treppenteilen so gekoppelt ist, daß sich die Treppenteile entfalten oder zusammenfalten, wenn sich der Gleitstein entlang der Führung bewegt, und
• einem Zweigelenkglied, das mit dem Gleitstein gelenkig verbunden ist, wobei der Winkel α zwischen diesem Stab und der Führung gleich oder kleiner als 90° ist.
• einem gelenkig an der Rahmenwange befestigten Winkelhebel, dessen einer Arm gelenkig mit dem Zweigelenkglied verbunden ist und vorzugsweise von einem elektrischen Linearmotor angetrieben wird, der gelenkig zwischen dem anderen Arm des Winkelhebels und dem Rahmen bzw. einem darauf befestigten Beschlag angebracht ist.

For tripartite foldable loft ladders, a docking system is presented in this invention. This coupling system consists at least of:

• a guide, preferably a linear guide, which is mounted on the uppermost part of the staircase or on the hatch cover;
• a sliding block disposed on a guide and coupled to the stair parts so that the stair parts unfold or collapse as the sliding block moves along the guide, and
• a two-link link articulated to the slider, the angle α between this rod and the guide being equal to or less than 90 °.
• an angle lever pivotally mounted on the frame cheek, one arm of which is pivotally connected to the Zweilenkenkglied and preferably of one electric linear motor is hingedly mounted between the other arm of the angle lever and the frame or a fitting attached thereto.

In order to avoid a high stress on the gearbox and the engine during use of the stairs and during the stairway extension, this two-link link can be replaced by a tensile-pressure gas spring or equivalent.

If no spring or insufficient spring force for balancing the weights is arranged, this drive rod is only zugbeansprucht. The above-mentioned two-link link can be replaced by a rope, the linear motor by a cable.

The desired coupling of the opening of the hatch cover with the unfolding of the stairs one behind the other can be achieved by the o. G. Coupling system can be realized. It is easy to construct the staircase so that the sliding block moves only after opening the hatch cover along the guide and that the sliding block is withdrawn by the Zwtigelglied first before the closing of the flap lid, d. H. the stair parts are folded first.

Fs is not mandatory that the floor stairs are provided with a viable hatch cover. Instead, a durable metal frame can be used. For foldable and retractable loft ladders, all mechanisms, including the docking system described above, may also be attached directly to the uppermost staircase portion in use.

In order to be able to simply fold or fold down foldable loft ladders, the arrangement of an initial angle β between the upper staircase part and the articulated staircase part in the folded-up state of the staircase is provided in the invention, so that both the dead spots of the push-pull chain formed therebetween the dead spots of the above-described Viergelenkgeuiebes for the coupling of two hinged stair parts can be avoided.

Since the solutions presented here for coupling the movements of two articulated stair parts, to avoid higher loads in the transmission and for coupling two movements in a row are very simple, reliable and maintenance-free, the motor-driven folding staircases can be produced inexpensively. In addition, the folding staircases can be virtually as massive as required for convenient and safe use, because the weight problem, which usually sets the limit for manually operated folding staircases, here be solved by a motor drive.

In order to compensate for the dead weight or to keep the required engine power as small as possible or to enable a one-sided motor drive, springs can be used.

Fig. 1:

eine erfindungsgemäß ausgebildete dreiteilige faltbare Bodentreppe im verstauten Zustand in einem Längsschnitt,

Fig. 2:

diese Bodentreppe im zusammengefalteten Zustand und mit aufgeklapptem Lukendeckel in einem Längsschnitt

Fig. 3:

diese Bodentreppe im entfalteten Zustand bzw. im Gebrauchszustand in einem Längsschnitt,

Fig. 4:

eine erfindungsgemäß ausgebildete zweiteilige faltbare Wangentreppe mit einem zusätzlichen Schubgelenk im Viergelenkgetriebe und im verstauten Zustand in einem Längsschnitt,

Fig. 5:

diese Wangentreppe im entfalteten Zustand bzw. im Gebrauchszustand in einem Längsschnitt,

Fig. 6:

die Details der Verbindung zwischen dem Linearmotor und der Kurbel mit einer Bahnführung, wobei sich die Wangentreppe im verstauten Zustand befindet, und

Fig. 7:

die Details der u. g. Verbindung, wobei sich die Wangentreppe im Gebrauchszustand befindet.

Two embodiments of the invention will be described below with reference to the drawings. It shows:

Fig. 1:

an inventively designed three-part foldable loft ladder in the stowed state in a longitudinal section,

Fig. 2:

this attic stairs in the folded state and with hatch cover opened in a longitudinal section

3:

these attic stairs in the unfolded state or in use in a longitudinal section,

4:

an inventively designed two-part foldable stringers with an additional sliding joint in four-bar linkage and in the stowed state in a longitudinal section,

Fig. 5:

this stringer staircase in the unfolded state or in use in a longitudinal section,

Fig. 6:

the details of the connection between the linear motor and the crank with a web guide, wherein the stringboard stairs is in the stowed state, and

Fig. 7:

the details of the ug connection, wherein the staircase is in use state.

1, 2 and 3, a three-part foldable loft ladder with stair parts 3, 4 and 5 is shown on a hatch cover 2, which is suspended on both sides by means of two hinges 6 and 7 on the frame che 1 by the attached fittings 8. The limitation of the opening stroke of the hatch cover is made by the attached to both frame cheeks pins 25, which prevent further extension of the rods 9 and also carry the load during use. At the hatch cover 2, the uppermost staircase part 3 is fastened by means of the spacers 26. Two linear guides 12, each with a sliding block 13 are also attached to the hatch cover 2. The sliding blocks 13 are connected to each other by the flat steel 18. A sliding block 13 is driven by a two-link member 15. This member 15 has an angle α (α <90 °) relative to the linear guide 12 and is driven by a fixed to the frame cheek 1 angle lever 16, which in turn is driven by a linear electric motor 17.

Unintentional lowering of the hatch cover 2 from the stowed state (FIG. 1) can normally be avoided either by the use of a self-locking linear motor 17 or by a self-locking gear formed between the two-link member 15 and the bell crank 16. This self-locking of the transmission can also by a brief donning or pressing the angle lever 16, z. B. by means of a cable to be solved, so that the stairs remain manageable even in case of power failure or engine failure.

The middle stair part 4 is hingedly connected to the top stair part 3. Its movement is coupled by a two-link member 19 to the movement of the sliding block 13. In the folded state there is an initial angle β between the two stair parts 3 and 4, so that the thrust crank mechanism formed therebetween and the four-bar linkage for the coupling of the staircase parts 4 and 5 can not fall into their dead spots. The generation of this initial angle β can by different Methods are realized and is simple. For example, the fittings between the stair parts can be designed so that this angle is formed.

In order to avoid high stress on the transmission and the engine during use of the stairs or during the extension of the stairs, the two-link member 15 or the two-link member 19 can be designed so that when it exceeds a predetermined compressive force caused a large elastic deformation becomes. Alternatively, one of the two-link elements can be replaced by a tensile-pressure gas spring. Another advantage of this design is that the motor can always be switched off regardless of the ceiling height by its built-in limit switch.

The lowermost stair part 5 is on the one hand directly hinged to the middle stair part 4 and on the other hand by means of a two-link member 22, which is designed as a lower railing of the stairs (the upper, directly attached to the hatch cover 2 railing is not shown), connected to the uppermost stair part 3 , This results in the four-bar linkage, so that the unfolding and folding of the middle staircase part 4 and the lower staircase part 5 is coupled together (see Fig. 2 and Fig. 3).

When starting up the stairs from the state shown in Fig. 1, the linear motor 17 is set in motion or the motor 17 is extended. The hatch cover 2 works accordingly on the sliding blocks 13 but not yet move along the Linearführmgen 12. Only when the unfolding of the hatch cover 2 has reached its full open position (Fig. 2), the sliding blocks 13 move along the linear guides 12 through the further extension of the linear motor 17. As a result, the stair parts 4 and 5 unfold correspondingly to the state of use (FIG. 3).

The stowing of the stairs from the state of use (FIG. 3) takes place by reversing the linear drive or the linear motor 17 is shortened. The stair parts 4 and 5 are first folded up to the position shown in FIG. 2, only then is the folding of the hatch cover 2 to the position shown in FIG. 1.

Fig. 4 shows a two-part foldable staircase with a staircase, which is normally used to reach galleries or false ceilings, when stowed, and Fig. 5 shows them in the condition of use. The staircase consists of the stair parts 34 and 35 and the steps 39. The push rod 38 with a shoe joint is shown symbolically, so you can clearly and clearly recognize its operation. The position of this thrust joint may be anywhere between the two ends of the rod.

One end of the upper stair part 34 is fixed to the shaft 33. Also attached to the shaft 33 is a crank 40 having the track 41 (Figures 6 and 7). The crank 40 is driven by a linear motor 42. The shaft 33 is angeorduct in the fastened to the ceiling 30 fittings 31.

The lower stair part 35 is hinged to the other end of the upper stair part 34. The push rod 38 is disposed between the lower staircase portion 35 and the ceiling 30 by means of the fittings 31 and 36. When stowed, the push rod 38 is slightly extended. During the unloading of the stairs, the rod 38 is collapsed to its minimum length and then acts as a two-link link. The above four-bar linkage for coupling two hinged stair parts is formed and the stair parts can thereby be brought into their state of use.

In Fig. 6, the details of the connection between the linear motor 41 and the crank 40 with the web guide 41 are shown in the stowed state of the stairs, and in Fig. 7, these in use. The linear motor 42 is hingedly connected to a fixed frame 43 by a normal hinge. The other end of the motor drives the guide track 41 of the crank 40 by means of a hinge pin 44. When stowed, the pin 44 is normally at the end of the track 41 (Figure 6). In use, however, the pin 44 is normally not at the end of the track 41 (Fig. 7), so that an adjustment of the ceiling height by a change in inclination of the stairs is possible. In addition, in the engine 42 and the transmission no stress during use of the stairs or no higher stress during the extension of the Stairs occur. The motor 42 can always be switched off by the built-in limit switch (simple operation).

When starting up the stairs from the state shown in Fig. 4, the linear motor 42 is set in motion or the motor 42 is extended. As a result, the stair parts 34 and 35 unfold correspondingly and with the aid of the pressure rod 38 until they are in use (FIG. 5). The motor can continue to extend until it is switched off by the built-in limit switch. Then the pin 44 is no longer at the end of the guideway 41.

The stowing of the stairs from the use state (FIG. 5) takes place by reversing the linear drive or the linear motor 42 shortens. The pin 44 first moves to the end of the track 41 and then attracts the crank 40. The staircase parts 34 and 35 are thereby brought into the stowed state (FIG. 4).

Although the invention is in the o. G. Embodiments have been described in detail, but this should be considered that these details are for demonstration purposes only and are not intended to limit the scope of this invention. Other embodiments are possible without departing from the scope of this invention.

Claims (4)

1. Motor-driven foldable ladders with a four-bar linkage to couple the movements of two on each other hinged ladder sections are so characterized that the linkage consists of:

   - an in operative position upper ladder section (4 or 34) which is hinged on a frame and on an in operative position under ladder section as driver in the linkage;

   - the in operative position under ladder section (5 or 35) which is hinged on the upper section and on a singular link as coupler in the linkage;

   - the singular link (22 or 28) which is hinged on the in operative position under ladder section and on the frame as Follower in the linkage; and

   - the frame (3 and 20 respectively 30 and 31) on that the upper ladder section and the singular link are hinged and which is by three-section foldable ladders the uppermost ladder section (3) usually fixed to a cover (2) respectively the mounting plate (20) fixed to the uppermost ladder section respectively by two-section foldable ladders the floor (30) respectively the mounting plate (31) fixed to the floor.
2. Motor-driven foldable ladder as described in claim 1 is so characterized that the four-bar linkage (34, 35 38 and 30 respectively 31) results only by hindering of the relative movements in one or more additional joints which are constructed as part of the linkage, and that the formation of the four-bar linkage occurs before the ladder sections unfold into their operative position.
3. Motor-driven two-section foldable ladder as described in claims 1 or 2 is so characterized that a crank (40) with a guideway to avoid high stress in the driving mechanisms and in the motor during using of ladder or unfolding into operative position is constructed wherein the crank (40) is fixed to the in operative position upper ladder section, is hinged on the floor (30) and is driven usually by a linear motor by means of a pin (44) in the guideway.
4. Motor-driven three-section foldable ladder as described in claims 1 or 2 is so characterized that a coupling assembly for opening of cover and for unfolding of ladder sections one after another is constructed wherein the coupling assembly consisted at least of:

   - a guide, preferably a linear guide (12), which is fixed to the in operative position uppermost ladder section (3) or to the cover (2),

   - a slider (13) which is mounted on the guide (12) and is coupled with the ladder in a manner that the ladder sections fold or unfold retract respectively when the slider moves along the guide,

   - a singular link (15) which is so constructed that one of his ends is pivotally connected to the slider (13) where the angle α between this link and the guide is equivalent to or less than 90° and

   - an on the frame pivoted bent lever (16) on one of whose ends the singular link (15) is hinged and which is driven preferably by an electrical linear motor (17) which is hinged between the other end of bent lever (16) and the frame (1) respectively the mounting plate (27) fixed to the frame.

Images