GB2443182A

GB2443182A - Stair lift

Info

Publication number: GB2443182A
Application number: GB0607610A
Authority: GB
Inventors: July Strupinsky
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-16
Filing date: 2006-04-18
Publication date: 2008-04-30
Also published as: IL174341A0; GB0607610D0

Abstract

A stair lift comprises a smooth guide rail 12 engaged by a friction drive wheel 3. The combined weight of a person being carried and a seat 2 is applied to the drive wheel 3 through a lever 5 which supports the seat, this weight being multiplied by the lever arrangement to prevent slippage of the friction drive wheel. The seat 2 is mounted on the lever 5 through a pivot connection 23, 53 which allows the seat to remain upright.

Description

Lift system and method This invention relates to a lift system with

means allowing it to be installed in stairways of existing homes.

The invention claims priority from the patent application No. 171+351+1 filed in Israel on 16 March 2006 by the present applicant and entitled "Lift system and method" At present, there are homes with several levels with no elevators. People may find it difficult to climb one or more flights of stairs. The problem may be especially difficult to elder people, ill persons or persons with disabilities.

Thus, a person living on a higher floor may suddenly find it difficult to get home or out.

To address this problem, various self-propelled stair lift systems have been proposed, which strive to cope with space limitations in buildings with no space for conventional elevators systems.

Such stair lift systems have, however, various disadvantages, for example due to their low maneuverability.

Other lifts may block the stairways, which is inconvenient and may be dangerous in an emergency.

Some disadvantages of prior art lift systems are related to the propulsion mechanism, which might use rack loading or engagement of driving wheel with stationery chain (U.S. patent 5720364 for instance).

The available trajectory of such stairlift is limited to either a straight line or a large radius curve. Therefore using this stairlifts in common houses obstructs the stairs for pedestrians, which is unacceptable.

Another prior art is a stair lift system with variable force friction drive (international publication number WO 02/05617 dated 24.01.2002).

It describes a guide mounted on a guard rail. A drive unit mounted in the seat increases seat size and reduces passage's size on the stairs for pedestrians. This prevents the usage of this stair lift in common houses.

Another prior art is a stair lift system of a Swiss firm called "HOGG".

This stair lift comprises a guide mounting on the ceiling above the middle (in cross section) of the stairs in order to guarantee necessary turning radius for gear rack mechanism.

In this case, the seat in middle of the stairs completely prevents passing through for pedestrians walking on the stairs.

Blocking of the stairs for pedestrians in common houses is absolutely inadmissible, because of the difficulties arising in emergency circumstances, such as fire, evacuation of sick people, etc. The present invention features a lift system which can be used in conjunction with existing stairways.

The lift system uses a guide rail which is installed on the inner side of the stairways, at a lower location such as the inner guard rail. This structure has the advantage that it does not causes a disturbance to people. The stairs can be used as well.

The lift can be installed in existing buildings and in stairways where there is no elevator, and at a reasonable cost.

The novel lift comprises a foldable seat, which can take one person.

Preferably, the seat is always folded when the lift is without a passenger therein.

The lift further includes grasping means to a side rail, with means for clasping the rail with great force, so it reliably engages the rail and will not slide down. The rail, driving wheel and counter wheels are all smooth, that is without gear teeth thereon.

An electric motor drives the lift along the guide rail in the stairway.

In a preferred embodiment, the current stairlift may use the self-propelled maneuverable device according to Israel patent No. 122362, patented by the present applicant.

Thus, the new lift can be used in private and shared buildings, due to its ability to move on a guide curve with small radius like the radius of a guard rail.

In order to prevent obstruction to pedestrians, the guide mounting is placed above or below, and in parallel to, a guard rail. There is also a driving mechanism, which does not block the stairs and guarantees free passage for pedestrians on the stairs.

Some of the characteristics of the novel lift system: 1. A strong grasp of a lift to a rail using a hoist or lever, thus the weight of the lift as well as additional pressure is used for grasping the rail by a motor's wheel which may be mounted through a gear.

2. Use of smooth rail in a reliable system: Due to the strong force thus created, there is a large friction force and the lift will not slip. Thus, despite the fact that the rail is smooth and without gears, the lift will not slip.

As the motor's wheel rotates, the lift moves steadily and reliably up or down.

3. Since the rail is smooth without gears, sharp turns are allowed.

Thus, a 180 degrees turn can be done within a diameter of about 30 centimeters. -Li-

The rail can thus be located near the handrail at about the central part of the stairways -so that doors and other openings will not be blocked. The system can be used in residential buildings having several floors. A 90 degrees turn at the low end of the rail allows to store the lift away from the stairs, so as not to obstruct the stairs when not in use.

The lift is for one person, so it is small. A seat without a passenger is always folded and may include means for easily removing it from the lift in case of emergency. This is important to prevent blocking of the stairs, such as to allow fast evacuation when there is a fire.

5. A novel sliding structure allows the seat to remain always in an upright orientation, despite the rail segments being horizontal or slanted. This achieves a user's comfort during the use of the lift.

6. Increasing the normal force applied on the rail. A long lever is achieved, to multiply the weight by a large number. In prior art, the weight is the weight of the lift plus that of the occupant.

In the new lift, however, the normal force applied on the rail, causing the desired friction therewith, is larger. This will prevent the lift from sliding on the rail, therefore the driving wheel will reliably move the lift up or down, as desired.

7. Simple structure, is low cost and reliable.

8. Shorter lever arm achieves a more stable structure (less swinging during the movement of the lift). The ability of the seat for spontaneous swinging is thereby reduced.

9. Novel rotary joint between seat and lever arm, using rotary rail and wheel rotating thereon, for fast, simple and easy removal of the chair from the lift. When it is desired that the seat not to interfere with people's movement on the stairs, the seat is simply taken off the lift.

Fig. 1 illustrates a front view (from the rail side) of a personal lift system installed in a stairway.

Fig. 2 details a cross-sectional side view of the mechanism holding the smooth rail Fig. 3 details a top view of the two-wheel, curvature-following mechanism holding the smooth rail The following invention shell now be described by way of example, and with reference to the accompanying drawings.

The lift 1 is installed over the stairs 32. The lift 1 includes a seat 2 for a person sitting thereon to be transported along the stairs.

The seat 2 is supported on a upper seat support (slider) 23 attached thereon.

The support 23 preferably includes ball bearings which may slide on the upper support rail (channel) 53, to keep the seat 2 upright when the angle of the power lever 5, which is attached to the lift 1, changes.

Other rotary joint means may be used to connect the seat 2 to the lever 5, however, the embodiment as illustrated has the additional advantage that it allows for fast, simple and easy removal of the chair 2 from the lift. When it is desired that the seat 2 not to interfere with people's movement on the stairs, the seat is simply taken off the lift by pulling it up, so the slider 23 disengages from the rail 53.

The weight of lift seat plus occupant, which is applied by means of slider 23 on the lever 5, is multiplied by the ratio Force multiplication= In lever length (a) 55/ Out lever length (b) 56 The friction between the rail 12 (guide, iron flat) and the drive wheel 3 is proportional to the force applied by support means (23), times the force multiplication (plus the weight of lever 5). Thus, a large friction force is achieved, to prevent the wheel 3 from slipping on the rail 12, despite the fact that the rail 12 is smooth with no gear teeth thereon.

Preferably, to prevent sliding on the rail, the formula: a/b > 14*sin(alpha) wherein alpha is the slope of the stairs.

A coefficient of 23 may be used instead of 14, for example.

The lift mechanism thus includes a counter wheel 4 with a normal axis for counter wheel 42, a semiaxie for power lever 8, a main shaft 9, within a drive unit 10 with a torque arm 11.

A shorter lever arm (a) 55 in the structure as illustrated will achieve a more stable structure (less swinging during the movement of the lift).

Fig. 2 details a cross-sectional side view of the mechanism holding the smooth rail, illustrating means for the lower wheels 4 to rotate sideways.

The drive wheel 3 rotates about the main shaft 9. The wheel 3 engages the rail 12 (guide, iron flat) with a large friction force. There are two counter wheels 4, each in a counter wheel housing 44 which can rotate about axis 42 which is normal to the guide 12.

This rotation is required to adapt to a curved rail 12, wherein a different angle of wheels 4 is required.

Fig. 3 details a top view of the two-wheel, curvature-following mechanism holding the smooth rail 12 on a curved section of the rail.

Each of the wheels 4 is required to point in a different direction, as illustrated. The vertical normal axis for counter wheel 42 for each of the wheels 4, will allow such rotation of the wheels 4. The rotation about each axis 42 is over an axis normal to the surface of the drawing.

It is possible to use a structure wherein the lever 5 applies force on the counter wheels 4, and the driving wheel is on the other side of the rail.

Either one or more counter wheels may be used.

Various embodiments of the present invention will become apparent to persons skilled in the art upon reading the present disclosure together with the drawings. Other embodiments of the invention may be implemented, without departing from the spirit and scope of the present invention.

Claims

What is claimed is: 1. A stair lift system comprising a smooth guide rail means installed along and at the side of the stairs on the inner part of a stairwell, seat means for carrying a person seated thereon, maneuverable device means for moving the system along the rail using a smooth driving wheel acting on the rail, and force multiplying means for applying on the rail, through the driving wheel, a force larger than the weight of the seat and its occupant, wherein the force multiplying means is located between the seat and the maneuverable device means and there is a rotary joint between the seat and force multiplying means.
2. The stair lift system of claim 1, further including means for its automatic folding when it is without a passenger.
3. The stair lift system of claim 2, further including means for its easy disassembly in an emergency.
4. The stair lift system of claim 1, wherein the force multiplying means include a lever means.
5. The stair lift system of claim 1, further including a rotary joint means between the force multiplying means and the seat.
6. The stair lift system of claim 1, wherein the rotary joint means comprise an upper seat support (slider) attached to the seat and an upper support rail (channel) attached to the force multiplying means.
7. The stair lift system of claim 1, wherein the lift is attached to the rail by means of a driving wheel and a counter wheel located on the opposite side of the rail. -9--
8. The stair lift system of claim 1, wherein the lift is attached to the rail by means of a driving wheel and two counter wheels located on the opposite side of the rail.
9. The stair lift system of claim 8, wherein each of the two counter wheels is mounted on a structure with means for its rotation on a plane so as to allow the two counter wheels to follow a curvature in the rail.
10. The stair lift system of claim 1, wherein the force multiplying means include a shorter lever arm to achieve a more stable structure with less swinging during the movement of the lift.
11. A stair lift system comprising a smooth guide rail means installed along and at the side of the stairs on the inner part of a stairwell, seat means for carrying a person seated thereon, maneuverable device means for moving the system along the rail using a smooth driving wheel acting on the rail, and force multiplying means for applying on the rail, through the driving wheel, a force larger than the weight of the seat and its occupant, wherein the force multiplying means is located between the seat and the maneuverable device means, and a rotary joint between the seat and force multiplying means includes support means attached to the seat and sliding on an upper support rail (channel) attached to the rest of the lift system.