WO2013081522A1

WO2013081522A1 - Patient lift trolley

Info

Publication number: WO2013081522A1
Application number: PCT/SE2012/050748
Authority: WO
Inventors: Magnus Holmberg; Magnus BRÄNNSTRÖM
Original assignee: Handicare Ab
Priority date: 2011-12-02
Filing date: 2012-06-29
Publication date: 2013-06-06

Abstract

A patient lift trolley for movement in a suspended rail is provided. The trolley comprises at least one contact element for receiving electrical power from a connectable power supply arrangement when the trolley is arranged in the suspended rail, at least one spring arrangement resiliently connecting the at least one contact element with a body of the trolley such that the at least one contact element resiliently contacts the power supply arrangement when the trolley is arranged in the suspended rail, and a locking arrangement adapted to mechanically limit the protrusion of the contact element relative the body.

Description

PATIENT LIFT TROLLEY

Technical Field of the Invention

The invention relates to the field of patient lifts trolleys for movement in suspended rails. In particular, the invention relates to a patient lift trolley having contact elements for receiving electrical power.

Technical Background

Patient lifts which ride on suspended rails, for example ceiling-mounted rails are commonly used as an aid for lifting, lowering and moving persons who need such assistance, for example patients, elderly or disabled persons. Such a patient lift usually comprises a hoist device for lowering and raising for example a harness holding the patient. The hoist may be powered by an electrical motor. Depending on the need of the person who needs assistance, the patient lift may also comprise a motor for driving the patient lift along the rail of a rail system attached to, for example, the ceiling. The electrical power necessary for these motors may, for example, be delivered directly from an externally arranged power supply via a cable, or from a rechargeable battery or from an accumulator arranged in the patient lift housing. There exists a large variety of arrangements for delivering electrical power in order to either drive the patient lift directly or for charging batteries or accumulators.

Patient lifts which comprise batteries or accumulators and are adapted to be charged at certain predetermined positions, usually at an end position of a rail, are known in the prior art. One such example is described in US5939857, where a charging system for charging the batteries of ceiling-mounted patient lifts is disclosed. The charging system is mounted on top of the trolley and comprises multiple spring-biased brass pins having upper ends extending upwardly from the trolley for contacting rail-mounted charging stations arranged at specific positions along the rail. This system requires that the trolley is placed at certain positions for it to be charged.

In US201 1000015 another system having a patient lift including a trolley adapted to ride along, for example, a ceiling-mounted track is disclosed. The trolley comprises contacts which are biased outwardly from the trolley, for example, by springs such that the contacts are in contact with track

conductors for supplying electrical power to the patient lift. The trolley is configured to the geometrical outline of the ceiling mounted track such that the patient lift receives power during operation, i.e. regardless of its position along the track. One problem with the power supplying systems disclosed in US201 1000015 and US5939857 is that these systems cannot be combined without substantial modifications or adaptations of the systems.

Summary of the Invention

It is an object of the present invention to provide a patient lift trolley which may be used in a modular suspended rail arrangement having conductor(s) for supplying electrical power being arranged at different distances from the trolley. A further object is to provide a patient lift trolley which may be used for both in-track power, i.e. power is supplied from track conductor(s) along the rail, and for charging batteries at predetermined positions. According to a first aspect of the invention, a patient lift trolley for movement in a suspended rail is provided. The trolley comprises at least one contact element for receiving electrical power from a connectable power supply arrangement when the trolley is arranged in the suspended rail, at least one spring arrangement resihently connecting the at least one contact element with a body of the trolley such that the at least one contact element resihently contacts the power supply arrangement when the trolley is arranged in the suspended rail, and a locking arrangement adapted to mechanically limit the protrusion of the contact element relative the body. In other words, the trolley comprises at least one contact element being connectable with at least one conductor of a power supply arrangement, where the contact element(s) is resihently coupled to the body of the trolley by means of a spring arrangement. The spring arrangement acts on the contact element(s) such that the at least one contact element resihently contacts the at least one conductor of the power supply arrangement when the trolley is arranged in the suspended rail. The spring arrangement or the contact element(s) is lockable by means of a locking arrangement to mechanically limit the protrusion outwardly of the contact element relative the body. Put differently, a locking arrangement is adapted to lock the spring means of the spring arrangement in a partially biased state such that the protrusion of the contact element relative the body of the trolley is reduced relative an unbiased and unlocked state. Put differently, the trolley is operable in at least a retracted state and a non-retracted state. In the retracted state, the contact element is retracted relative the body of the trolley, i.e. the retracted state corresponds to when the protrusion of the contact element is limited by the locking arrangement. In the non-retracted state, the contact element is protruding relative the body of the trolley, i.e. the non-retracted state corresponds to when the protrusion of the contact element is not limited by the locking arrangement.

According to a second aspect of the invention, a patient lift device is provided. The patient lift device comprises a patient lift trolley according to the first aspect of the invention, a hoist being suspended from the patient lift trolley, wherein the hoist comprises an electrical motor, and an accumulator or battery being coupled to the electrical motor and the contact elements. According to a third aspect of the invention, a suspended rail system is provided. The suspended rail system comprises at least one rail being adapted to be suspended and a patient lift device according to the second aspect of the invention. The invention is based on the insight that by providing a combined resilient and lockable attachment of the contact element(s) receiving electrical power relative the body of the trolley, a common patient lift trolley may be used in both suspended rail arrangements having conductor track(s) or other conductor arrangements arranged along the length of the rail(s) as well as suspended rail arrangements having charging station(s) arranged at predetermined position(s).

Thus, when the trolley is used in suspended rail arrangements having charging station(s) arranged at predetermined position(s), it is advantageous that the contact element(s) are lockable because unnecessary interaction between the contact elements and the suspended rail may be avoided.

Thereby noise due to friction between the contact element(s) and the rail and unwanted electrical contact between the contact element(s) and the rail may be avoided. Another advantage is that the charging station(s) in such a suspended rail arrangement may be advantageously designed with a shorter spacing between the power supply conductor(s) and the body of the trolley compared to the spacing between the conductors extending along the length of a suspended rail system with in-track charging or power. Thus, the contact element(s) may be connectable with the power supply conductor(s) of the charging station(s) when the locking arrangement is used to limit the protrusion of the contact element(s), but not with the rail.

In an embodiment of the invention, the at least one contact element is adapted to receive power from a connectable power supply comprising electrical conductor rails being arranged along the length of the suspended rail. This is advantageous because the patient lift may be supplied with electrical power and/or charge a battery or accumulator regardless of the position along the suspended rail. The electrical conductor rails may be arranged on an inner surface of the suspended rail.

In another embodiment of the invention, the at least one contact element is adapted to receive power from a connectable power supply comprising at least one conductor or conductor rail arranged at arbitrary position(s) along the suspended rail. The at least one conductor or at least one conductor rail may be arranged in the suspended rail(s) along portions of the length or may be arranged at certain positions.

In yet another embodiment of the invention, the at least one contact element is adapted to receive power from a connectable power supply comprising at least one conductor or conductor rail arranged in a charging station arranged at an arbitrary position along or adjacent to said suspended rail. In other words, the at least one contact element may be adapted to be connectable with at least one conductor or conductor rail of a power supply, wherein the at least one conductor or conductor rail are arranged at an arbitrary position, for example at an end position of the suspended rail(s), to form at least one charging station.

In yet another embodiment of the invention, the at least one contact element is a metal wheel, a graphite wheel, a ball bearing wheel or a combination thereof or any other type of contact wheel suitable for receiving electrical power. In yet another embodiment of the invention, the at least one contact element is a trailing shoe or trailing contact. In yet another embodiment of the invention, the locking arrangement comprises at least one pin or peg. In yet another embodiment of the invention, the locking arrangement is a reciprocally moveable portion of the spring arrangement.

In yet another embodiment, the spring arrangement comprises a U-shaped member coupled to the contact element and at least one spring member arranged between said U-shaped member and a body of said trolley. The laterally protruding portions of the U-shaped member may be rounded on both sides in the longitudinal direction of the patient lift trolley. Thereby, the trolley may be inserted easier from beneath into an opening of a suspended rail is achieved.

Brief Description of the Drawings

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawing showing a currently preferred embodiment of the invention, wherein:

Fig 1 is an illustration of a patient lift trolley in accordance with an embodiment of the invention.

Fig 2 is an illustration of the embodiment in fig. 1 before the locking arrangement is applied.

Fig 3 is an illustration of the embodiment in fig. 1 with the locking arrangement applied. Detailed Description

In the following description, an embodiment of the present invention is described with reference to a patient lift trolley having two contact elements and two U-shaped spring arrangements. Fig. 1 shows a patient lift trolley 1 according to an embodiment of the present invention. The patient trolley has an elongated body 2 and wheels 3a-d rotatably coupled to the sides of the elongated body such that the patient lift trolley may ride in a suspended rail (not shown). A first and a second spring arrangement 4a, 4b are arranged in a recessed portion of the top of the patient trolley body 2. The spring arrangements comprise U-shaped bodies partially protruding in opposite directions from each other and laterally from the body of the patient trolley 2. The arms 4a1 , 4a2, 4b1 , 4b2 of the U-shaped bodies extend towards each other and partially overlap. The U-shaped bodies are slidable relative each other in the lateral direction, such that the overlap of the arms and the protrusion outwardly from the body of the trolley of the U- shaped bodies is adjustable. The spring arrangements further comprise two helical springs 5a, 5b arranged extending laterally in between the U-shaped bodies in order to force them laterally outwardly. The U-shaped bodies have tracks in the partially overlapping arms of the U-shaped bodies of the spring arrangements. Screws 6a, 6b are screwed from above through the tracks and extending through the partially overlapping arms tracks into the body 2 of the patient lift trolley. The screws 6a, 6b in cooperation with the tracks will guide and/or limit the protrusion outwardly of the U-shaped bodies. The laterally protruding portions of the U-shaped bodies of the spring arrangements 4a, b are rounded on both sides in the longitudinal direction of the patient lift trolley to facilitate easier insertion from beneath into an opening of a suspended rail. In accordance with the scope of the invention, it is understood that a single U- shaped body may be used in other embodiments.

A first contact element 7a and a second contact element 7b (not shown) are arranged partially recessed in recessions from beneath in the U-shaped bodies of the respective spring arrangements 4a, 4b. The contact elements are rotatably coupled thereto and are rotatable around an axis being perpendicular to the axes of rotation of the wheels 3a-d. The contact elements are furthermore partially protruding in the lateral direction of the spring arrangements 4a, 4b in order to be connectable with conductors of a power supply. The contact elements are formed as wheels, such as graphite wheels or ball bearings or other metallic wheels suitable to receive power in a suspended rail system, which are electrically conducting such that electrical power may be received through the contact elements. The electrical power is further connectable to motors and/or batteries and accumulators via cable lugs 8a, 8b which are arranged on top of the U-shaped bodies of the spring arrangements 4a, 4b and in electrical contact with the contact elements.

Fig. 2 shows a patient lift trolley 1 according to the same embodiment as shown in fig. 1. The patient lift trolley 1 is shown together with its locking arrangement 9a, 9b provided in the form of two pins or pegs 9a, 9b. The locking arrangement is adapted to cooperate with through holes 10a, 10b of the U-shaped bodies of the spring arrangements 4a, 4b. The through holes 10a, 10b are slightly elongated in the lateral direction and are located laterally adjacently to the tracks of the arms 4a1 , 4a2, 4b1 , 4b2 of the U-shaped bodies. By manually forcing the spring arrangements 4a, 4b towards each other in the lateral direction, the through hole 10a of the first spring

arrangement 4a aligns with a through hole of the arm 4b2 of the second spring arrangement 4b, and also aligns with a hole in the body 2 of the trolley. The through hole 10b aligns with holes of the first spring arrangement and the body of the trolley in an analogous manner. In accordance with the scope of the invention, it is understood that other types of locking arrangements may be used, such as various types of mechanical stops.

Fig. 3 shows a patient lift trolley 1 according to the same embodiment as shown in figs. 1 and 2. By inserting the pins or pegs 9a, b into the respective through holes 10a, 10b when the spring arrangements 4a, 4b are aligned as described above, movement in the lateral direction of the spring

arrangements is limited. In other words, the protrusion of the spring

arrangements and thereby also the protrusion of the contact elements is limited mechanically. The helical springs are thus locked in a partially compressed state. Because the through holes 10a, 10b of the U-shaped elements of the spring arrangements 4a, 4b are slightly elongated, resilient movement in the lateral direction of the springs arrangements and the contact elements is still possible. When the locking arrangement 9a, 9b is applied in this way, the contact elements still protrude in the lateral direction relative the body 2 of the trolley, although to a lesser extent than shown in figure 1 .

Figs. 1 and 3 thus illustrate the two different modes of operation. In the first mode, as illustrated in figure 1 , the contact elements protrude in such a manner that they are resiliently connectable with conductors or conductor rails arranged at a first lateral distance from the trolley. In the second mode, as illustrated in figure 3, the contact elements protrude in such a manner that they are resiliently connectable with conductors or conductor rails arranged at a second lateral distance from the trolley, where the second lateral distance is smaller than the first lateral distance. Thereby, the same patient lift trolley may be used in suspended rail systems having different spacing between the conductors or conductor rails. Advantageously, the patient lift trolley may be used for in-track charging or power in the first mode, i.e. it may be used in suspended rails having conductors rails arranged along the length thereof. In the second mode, the patient lift trolley may advantageously be used in a suspended rail system having charging stations arranged at certain

predetermined positions relative the rail, for example at end positions thereof. Although an exemplary embodiment of the present invention has been shown and described, it will be apparent to the person skilled in the art that a number of changes and modifications, or alterations of the invention as described herein may be made. Thus, it is to be understood that the above description of the invention and the accompanying drawing is to be regarded as a non- limiting example thereof and that the scope of the invention is defined in the appended patent claims.

Claims

1 . A patient lift trolley for movement in a suspended rail,

said trolley comprising:

- at least one contact element for receiving electrical power from a connectable power supply arrangement when said trolley is arranged in the suspended rail;

- at least one spring arrangement resiliently coupling said at least one contact element with a body of said trolley such that the at least one contact element resiliently contacts the power supply arrangement when the trolley is arranged in said suspended rail; and

- a locking arrangement adapted to mechanically limit the protrusion of said contact element relative said body.

2. The patient lift trolley according to claim 1 , wherein the trolley is operable in at least a retracted and a non-retracted state.

3. The patient lift trolley according to claim 2, wherein the protrusion of said contact element is limited by said locking arrangement in said retracted state.

4. The patient lift trolley according to claim 2 or 3, wherein the protrusion of said contact element is not limited by said locking arrangement in said non- retracted state.

5. The patient lift trolley according to any one of the preceding claims, wherein the spring arrangement or the contact element(s) is lockable by means of said locking arrangement to mechanically limit the protrusion outwardly of the contact element relative the body.

6. The patient lift trolley according to any one of the preceding claims, wherein said locking arrangement is adapted to lock a spring means of the spring arrangement in a partially biased state such that the protrusion of the contact element relative said body of the trolley is reduced relative an unbiased and unlocked state.

7. The patient lift trolley according to any one of the preceding claims, wherein said at least one contact element is a metal wheel, graphite wheel or a ball bearing wheel. 8. The patient lift trolley according to any one of the preceding claims, wherein said locking arrangement comprises at least one pin or peg.

9. The patient lift trolley according to any one of the preceding claims, wherein said spring arrangement comprises a U-shaped member coupled to said contact element and at least one spring member arranged between said U-shaped member and a body of said trolley.

10. A patient lift device comprising:

- A patient lift trolley according to any one of the preceding claims;

- A hoist being suspended from said patient lift trolley, said hoist comprising an electrical motor; and

- An accumulator or battery being coupled to said electrical motor and said at least one contact element.

. A suspended rail system comprising:

- at least one rail being adapted to be suspended and

- a patient lift device according to claim 10.

12. A suspended rail system according to claim 1 1 , further comprising a power supply arrangement having a charging station arranged at an arbitrary position along or adjacent to said suspended rail.

13. A suspended rail system according to claim 12, wherein said at least one contact element is adapted to receive power from at least one conductor or conductor rail arranged in said charging station.

14. A suspended rail system according to claim 12, wherein said at least one contact element is adapted to receive power from at least one conductor or conductor rail arranged in said charging station when said locking

arrangement is mechanically limiting the protrusion of said contact element relative said body.

15. A suspended rail system according to any one of the claims 1 1 -14, further comprising a power supply arrangement having at least one electrical conductor rail arranged along the length of said at least one rail. 16. A suspended rail system according to claim 15, wherein said at least one contact element is adapted to receive power from said at least one electrical conductor rail.