WO2017202987A1 - Stairlift with simplified transmission - Google Patents

Abstract

A stairlift (1) with simplified transmission which comprises an assembly (2) for conveying a passenger associated slideably along a pair of mutually parallel guides (3, 4), an upper one (3) and a lower one (4), which can be associated with a substantially vertical fixed structure; means (5) for the sliding actuation of the conveyor assembly (2) along the guides (3, 4) which comprise a driving pinion (6) associated with a corresponding toothing associated with the upper guide (3) and rotating integrally with a primary shaft (7), a stabilizer pinion (8) associated with a corresponding toothing associated with the lower guide (4) and associated in rotation with a secondary shaft (9), and transmission means (10) associated with such pinions (6, 8); the transmission means (10) comprise an idle pinion (18) interposed between the pinions (6, 8) and sliding friction means (20) interposed between the secondary shaft (9) and the stabilizer pinion (8).

Description

STAIRLIFT WITH SIMPLIFIED TRANSMISSION

The present invention relates to a stairlift with simplified transmission.

Stairlift devices are known which make it possible to scale one or more flights of stairs when seated and they are generally used for elderly persons or persons with reduced mobility.

Such stairlift devices consist, substantially, of a conveyor assembly that can slide along a pair of parallel guides, one upper and one lower, which are connected to a vertical fixed structure adjacent to the stairs. The conveyor assembly generally has a chassis to support a small armchair and a footboard for carrying the passenger and means of sliding actuation along the guides, which must enable the advancement of the entire assembly while keeping the armchair and the footboard in a fixed position with respect to the horizontal plane independently of the variation in inclination of the path defined by the guides, for example at landings.

To this end a first type of transmission is known, for example described in WO95/15909, which has a pair of pinions, one of which is driving and associated with a rotating drive engine and the other driven, which are engaged in respective toothings associated with the guides and are mutually coupled by way of a transmission chain.

This solution requires exceptional precision, both during machining and during installation, in executing the coupling between the pinions and the toothings associated with the guides. If there are defects, in fact, there can be slight variations of pitch between the pinions which could result in the system jamming or in any case in its stability being compromised.

In order to overcome these drawbacks, a solution is known, described in EP 1,053,968 Bl in the name of this applicant, in which the transmission system has an upper, driving pinion, meshed in the toothing of the upper guide, and a lower, idle pinion meshed in the toothing of the lower guide, between which are interposed friction means that are adapted to be actuated in order to make the lower pinion rotate integrally with the upper pinion when the inclination of the guides is less than a preset threshold value, so that the lower pinion acts as a stabilization element.

This solution, although an improvement with respect to the previous art, is not devoid of drawbacks among which is the fact that, when the friction means are engaged, the connection between the upper and lower pinions is rigid and does not allow slippages in order to compensate for unforeseen variations of pitch between those pinions which may arise owing to imperfections in construction or in installation.

Furthermore, the cost and the complexity of construction of the solution using friction and of the corresponding control circuit entail the necessity to provide two stairlift versions, with and without friction, to offer to users based on the intended path of the guides in the specific application.

In order to contain the installation costs, in fact, for paths that have a slope that is always greater than the aforementioned threshold value a stairlift without friction is generally offered, while for paths with a slope that is lower than the threshold value, a stairlift is offered that has friction and the corresponding control circuit.

For this reason, managing the production cycle and the stocks of such type of stairlift is rather complex, since different article codes need to be managed.

The aim of the present invention is to eliminate the above mentioned drawbacks in the background art, by providing a stairlift with simplified transmission that makes it possible to compensate any variations of pitch between the upper and lower pinions under any condition of use and independently of the geometry and of the slope of the path defined by the guides, so as to optimize the safety and reliability of the system.

Within this aim, an object of the present invention is to provide a stairlift that is simple and economic from the point of view of construction, to the point where it can be used universally independently of the geometry of the path of the specific application.

Another object of the present invention is to simplify the logistical management of stocks, both of components and of finished products for manufacturers.

Another object of the present invention is to provide a stairlift that does not require particular contrivances either in the machining, or in the installation of the guides.

Last but not least, another object of the present invention is to provide a simple structure which is easy and practical to implement, safe in use and effective in operation, and low cost.

This aim and these and other objects which will become better apparent hereinafter are achieved by a stairlift with simplified transmission, comprising an assembly for conveying a passenger associated slideably along a pair of mutually parallel guides, an upper one and a lower one, which can be associated with a substantially vertical fixed structure, means being provided for the sliding actuation of the conveyor assembly along said guides and comprising a driving pinion associated with a corresponding toothing associated with the upper guide and integral in rotation with a primary shaft, a stabilizer pinion associated with a corresponding toothing associated with the lower guide and associated in rotation with a secondary shaft, and transmission means associated with said pinions, characterized in that said transmission means comprise an idle pinion interposed between said pinions and sliding friction means interposed between said secondary shaft and said stabilizer pinion.

Further characteristics and advantages of the present invention will become better apparent from the detailed description of a preferred, but not exclusive, embodiment of a stairlift with simplified transmission, which is illustrated for the purposes of non-limiting example in the accompanying drawings wherein:

Figure 1 is a front elevation view, partially transparent, of a stairlift with simplified transmission according to the invention;

Figure 2 is a cross-sectional view taken along the line II-II of Figure i ;

Figure 3 is an enlarged view of a portion of Figure 2 corresponding to the sliding friction means.

With particular reference to the figures, the reference numeral 1 generally designates a stairlift with simplified transmission.

The device 1 comprises an assembly 2 for conveying a passenger which is associated slideably along a pair of mutually parallel guides 3, 4, an upper one 3 and a lower one 4, which in use are mounted in a cantilever fashion against a substantially vertical fixed structure, such as a wall or a railing adjacent to the stairs where the device is installed.

The guides 3 and 4 are constituted by respective profiled bars that are contoured to follow the path that the conveyor assembly 2 is to travel in relation to the shape structure of the stairs where the device 1 is to be installed.

The device 1 further comprises means 5 for the sliding actuation of the conveyor assembly 2 along the guides 3 and 4 which comprise a driving pinion 6 associated with a corresponding toothing provided in the upper guide 3 and rotating integrally with a primary shaft 7, a stabilizer pinion 8 associated with a corresponding toothing provided in the lower guide 4 and associated in rotation with a secondary shaft 9, and transmission means 10 associated with these pinions.

In more detail, the actuation means 5 comprise an upper pinion 13 and a lower pinion 14 that rotate integrally, respectively, with the primary shaft 7 and with the secondary shaft 9 and are engaged in the toothings of the upper guide 3 and of the lower guide 4.

The shafts 7 and 9 are arranged with a horizontal arrangement and the toothings, not visible in the figures, are defined by a series of holes distributed under the guides 3 and 4 in which the teeth of the pinions 13 and 14 mesh.

Furthermore, the actuation means 5 comprise an upper trolley 15 and a lower trolley 16 with rollers engaged above the guides 3 and 4, which are mounted so as to oscillate respectively about the primary shaft 7 and about the secondary shaft 9.

Also, the actuation means 5 comprise electric motor means 27 associated with an endless screw gear reducer 28 provided with an output pinion 29 that is directly coupled with the driving pinion 6.

Advantageously, the transmission means 10 comprise an idle pinion 18 interposed between the pinions 6 and 8, which is supported so that it can rotate about an intermediate shaft 19 parallel to the shafts 7 and 9, and sliding friction means 20 interposed between the stabilizer pinion 8 and the secondary shaft 9.

In this manner the secondary shaft 9 rotates simultaneously with the primary shaft 7, unless variations of pitch occur between the pinions 13 and 14 such that the twisting moment threshold on the secondary shaft 9 is exceeded, in which case the sliding friction means 20 allow the stabilizer pinion 8 to temporarily rotate idle with respect to the secondary shaft, so as to prevent damage to or malfunctioning of the device 1.

It should be noted that this solution does not require sophisticated elements for management and control, since it is sufficient to conveniently calibrate the sliding friction means 20, which automatically activate in the event of exceeding the corresponding threshold value of the twisting moment applied to the secondary shaft 9, and make it possible to compensate any variations of pitch under any conditions of use of the device 1, independently of the path defined by the guides 3 and 4.

The device 1 comprises a substantially box-like body 17 which accommodates the actuation means 5 described above, and which supports the conveyor assembly 2 which is substantially constituted by an armchair 11 arranged above the body 17 and a movable footboard 12 arranged in front of the body.

In more detail, the sliding friction means 20 comprise two friction discs 21 which are supported by corresponding flanged discs 24 which are arranged on opposite sides of the stabilizer pinion 8 and integral in rotation with the secondary shaft 9, and are interposed between a rigid shoulder 22 and elastic compression means 23 that are adapted to keep the friction discs and the stabilizer pinion packed.

Between the flanged discs 24 and the inside diameter of the stabilizer pinion 8 there is also a friction ring 25.

Preferably the elastic compression means 23 comprise a plurality of

Belleville springs 26 arranged in series along the secondary shaft 9.

Advantageously, there is a threaded ring 31 meshed with a female thread provided along the secondary shaft 9, which is arranged in abutment with the Belleville springs 26 and the axial position of which can be varied by acting on the threaded coupling in order to vary the preloading of these springs, which defines the threshold value beyond which the slipping occurs between the stabilizer pinion 8 and the friction discs 21 integral in rotation with the secondary shaft 9.

Also acting on the secondary shaft 9 is a safety assembly 30, known as a "parachute", which is not described as it is conventional.

Operation of the present invention is the following.

To activate the sliding of the conveyor assembly 2 along the guides 3 and 4, the motor means 27 are activated, which, by way of the endless screw gear reducer 28 and the output pinion 29, makes the driving pinion 6 that is integral with the primary shaft 7 rotate.

By way of the idle pinion 18 and the sliding friction means 20 normally being in contact, the rotation is transferred to the stabilizer pinion 8 and from this, by way of the sliding friction means 20, to the secondary shaft 9.

Under normal conditions, therefore, the shafts 7 and 9 with the corresponding pinions 13 and 14 rotate simultaneously.

In the event of overload of the secondary shaft 9 caused by loss of pitch of the pinions 13 and 14, the sliding friction means 20 activate to compensate such loss of pitch and restore the simultaneous rotation of the shafts 7 and 9 as soon as the overload condition ends.

In practice it has been found that the invention as described achieves the intended aim and objects and, in particular, attention is drawn to the fact that the stairlift is provided with a transmission system that makes it possible to compensate any variations of pitch between the pinions meshed in the guides under any conditions of use and independently of the path defined by those guides.

Furthermore, the stairlift according to the invention offers optimal levels of reliability and safety.

Last but not least, the stairlift according to the invention has a structure that is simple and relatively low cost, which therefore makes it possible to provide a single device version to offer to the customer for all possible installations.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, as well as the contingent dimensions and shapes, may be any according to requirements without for this reason departing from the scope of protection claimed herein.

The disclosures in Italian Patent Application No. 102016000054147 (UA2016A003820) from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A stairlift (1) with simplified transmission, comprising an assembly (2) for conveying a passenger associated slideably along a pair of mutually parallel guides (3, 4), an upper one (3) and a lower one (4), which can be associated with a substantially vertical fixed structure, means (5) being provided for the sliding actuation of said conveyor assembly (2) along said guides (3, 4) and comprising a driving pinion (6) associated with a corresponding toothing associated with the upper guide (3) and integral in rotation with a primary shaft (7), a stabilizer pinion (8) associated with a corresponding toothing associated with the lower guide (4) and associated in rotation with a secondary shaft (9), and transmission means (10) associated with said pinions (6, 8), characterized in that said transmission means (10) comprise an idle pinion (18) interposed between said pinions (6, 8) and sliding friction means (20) interposed between said secondary shaft (9) and said stabilizer pinion (8).

2. The stairlift (1) according to claim 1, characterized in that said sliding friction means (20) comprise a pair of friction discs (21) which are arranged on opposite sides of said stabilizer pinion (8), rotate integrally with said secondary shaft (9), and are interposed between a rigid shoulder (22) and elastic compression means (23) that are adapted to keep said friction discs (21) and said stabilizer pinion (8) packed.

3. The stairlift (1) according to claim 2, characterized in that said elastic means (23) comprise a series of Belleville springs (26) arranged along said secondary shaft (9).

4. The stairlift (1) according to claim 3 or 4, characterized in that it comprises a ring (31) that is screwed along said secondary shaft (9) to adjust the preloading of said elastic means (23).

5. The stairlift (1) according to claim 1, characterized in that said actuation means (5) comprise motor means (27) associated with an endless screw gear reducer (28) provided with an output pinion (29) that meshes directly with said driving pinion (6).

6. The stairlift (1) according to claim 1, characterized in that said actuation means (5) comprise an upper pinion (13) and a lower pinion (14) that rotate integrally, respectively, with said primary shaft (7) and with said secondary shaft (9) and are engaged in the toothings associated with said guides (3, 4).