WO2005036576A1

WO2005036576A1 - An electrical handset, in particular for electrically adjustable hospital and nursing beds

Info

Publication number: WO2005036576A1
Application number: PCT/DK2004/000693
Authority: WO
Inventors: Phillip Larsen
Original assignee: Linak A/S
Priority date: 2003-10-10
Filing date: 2004-10-11
Publication date: 2005-04-21
Also published as: EP1671340A1; PL1671340T3; CN1868016A; EP1671340B1; CN100570782C; DK1671340T3

Abstract

In electrically adjustable hospital and nursing beds there is a varying need for blocking certain adjustments of the bed. This blocking option is incorporated in the handset for the bed. The handset comprises a plurality of electrical switches (7) having an axially movable activating means (7') in a housing (7'), said activating means protruding a distance from the top of the housing. Above the activating means there is a likewise axially movable key which when being pushed down toward the switch steps on the activating means and presses it inwards toward the housing to activate the switch. A blocking means (12) may be moved from a parking position to a locked position, in which it partly rests on the upper side of the housing of the switch and partly serves as a stop for the overlying key at a level above the activating means of the switch in the rest position.

Description

An electrical handset, in particular for electrically adjustable hospital and nursing beds

The present invention relates to an electrical handset, in particular for electrically adjustable hospital and nursing beds as stated in the introductory portion of claim 1.

As for examples of adjustable hospital beds, reference may be made to EP 0 488 552 A1 to Huntleigh Technology pic and US 4425 673 to B-W Health Products, Inc. There are typically two controls for the bed, a handset by means of which the patient may adjust the mattress supporting structure to a desired position, as well as a controller at the end of the bed where the hospital staff may carry out adjustments of the bed, including adjustments beyond those which the patient can perform. At the same time, the staff can block medically inadmissible adjustments for the given patient so that the patient does not unintentionally activate an inadmissible position; in case of fracture of the femur, e.g. raising of the leg section.

Rather than a separate handset and a controller, it may be desirable exclusively to have the handset. For nursing beds, which are typically not as technically advanced as hospital beds, and which are exclusively equipped with a handset, it may be expedient to have a blocking of certain adjustment functions.

CH 681 833 to Magnetic Elektromotoren AG discloses a handset for hospital beds having a blocking mechanism for various functions. The control is a pneumatic control, and the keys are arranged in pairs, one for activating the function, the other for returning to the starting position. The blocking device operates purely mechanically with a pin having two wings arranged between two sets of keys. When the pin is rotated by a spanner intended for the purpose, the two wings may be moved inwards below a

flange on the keys and thereby prevent the keys from being pushed in. In an electrical handset from the same company, described in CH 691 638 to Magnetic Elektromotoren AG, the keys are blocked purely electronically by a separate magnetic card which cooperates with a reed switch in connection with the keys.

The invention is based on handsets, using small square brick-shaped switches having a round push-button on the upper side called tactile switch or tact switch. The switches are placed below a resilient tongue in the upper side of the handset, having adhered thereto a sheet with graphics that localize the key and its functions. Pressure on the sheet causes the tongue to be pushed in and affects the push-button on the switch. The travel of the push-button is very modest, viz. of the same order as the tolerances of the objects, which makes it difficult to have a mechanical lock. This also manifests itself in the foregoing, where a mechanical solution is selected for the pneumatic handset and an electronic solution for the electrical handset.

The object of the invention is to provide an electrical handset with mechanical locking of the keys.

As stated in claim 1 , the handset according to the invention is characterized by comprising a plurality of electrical switches having an axially movable activating means in a housing, said activating means protruding a distance from the top of the housing, a key, likewise axially movable, provided above the activating means, which when being pressed towards the switch, steps on the activating means and pushes it inwards toward the housing to activate the switch, and a blocking means which may be moved from a parking position to a locked position, in which it partly rests on the upper side of the housing of the switch and partly serves as a stop for the overlying key at a level above the activating means of the switch in a rest position. This provides a simple and safe mechanical solution for the blocking of an electrical switch, also even though its activating means has a limited travel. The essential point is that the reference of the blocking means is the housing of the switch which is the most direct reference for the activating means.

In an embodiment, the blocking means comprises a recess having a narrow part which is just capable of accommodating the activating means, and an expanded part which allows passage of the key to affect the activating means. The expanded part of the recess might be larger than the circum- ference of the switch, whereby the blocking means might be pressed elasti- cally down over the switch when the key is activated. However, it is preferred that the lower side of the blocking means, irrespective of its position, rests on the upper side of the housing of the switch. The position of the blocking means is thus constantly determined exactly relative to the switch.

Instead of resting directly on the housing of the switch, the blocking means may rest indirectly thereon via a bridge element which, with a plane part, rests directly on the upper side of the housing of the switch, and which is formed with a bore for the activating means of the switch which protrudes above the flat element at least by a height corresponding to its travel, and the bridge element is secured to the substrate which carries the switches. The flat element may be made plane and serve as a slide face for the blocking means, which thereby obtains a good support.

The blocking means may be configured as a slide which may be moved to and fro in the axial direction. With the arrangement of the keys in pairs, as mentioned initially, the slide may extend transversely and operate both keys. Displacement from one side to the other may cause the keys to become blocked and released, respectively. The slide may also be arranged with its side edges in a groove in the upper part of the handset carrying the keys, and there may be a snap-lock engagement to hold the slide in its respective positions. More expediently, the slide may be arranged on the bridge element, guided on the upper side and the side edges thereof. The sides of the handset may be formed with recesses for the insertion of a spanner having a spade-shaped end for displacing the slide. The recess may be covered by a membrane for water-tight construction of the handset.

Alternatively, the blocking means may be constructed to be rotatable between the non-locked position and the locked position, and it may be adapted to operate one or more switches. In case of two switches arranged in a pair, the blocking means is constructed as a flat or essentially flat element with recesses for two switches and with a pivot pin disposed between the two recesses. The pivot pin extends out on the front side of the handset between two keys, and the upper side of the pivot pin is configured for non- rotational reception of the end of a spanner for rotating the blocking means between the non-locked position and the locked position. It will be appreciated that the flat element is arranged in a plane in parallel with the upper and lower sides of the handset, whereby the handset may be made flat, e.g. in contrast to the above-mentioned CH 681 833 in which the blocking means has flaps perpendicular to the upper and lower sides of the handset.

When a bridge element is provided, as mentioned before, the blocking means may be mounted on it. For this purpose, the rear side of the blocking means may have a circular elevation which is received in a corresponding countersink in the bridge element.

It is a requirement that the handset for hospital and nursing beds is water- and moisture-proof, as the handsets are washed and disinfected in step with the exchange of patients. Typically, the handset consists of two plastics shells, viz. a lower part and an upper part which together form a closed housing. The plastics shells are assembled either by ultrasonic welding or are screwed together with an intermediate seal in the assembly line. To seal the passage for the pivot pin, the flat element is formed with a groove up to the pivot pin for a seal for sealing engagement internally with the upper part.

For a safe feeling that the blocking means is at least in the locked position, snap locking means may be provided between the blocking means and the housing of the handset for releasable securing of the blocking means. The snap locking means may simply consist of a local bulge or a pin in connection with a corresponding indent. When the blocking means is rotated, the engagement will then be recognized with certainty. Another way of constructing the snap locking means is to constrict the transition to the recess which holds the activating means in the locked position. On the other hand, the activating means is then affected by transverse forces at locking as well as at release, which may be inexpedient.

To indicate whether the keys are in a locked position or in a non-locked position, the blocking means may be provided with indicators which, by displacement, are moved to a window visible on the front side of the handset. In a simple manner, it may be a red mark which is moved to the window so that, in the locked position, it is visible through a transparent section of the cover sheet.

Further features of the invention will be elucidated in connection with the following description of an embodiment of the invention with reference to the accompanying drawing, in which:

Fig. 1 shows a perspective view of the upper part for a handset, fig. 2 shows a close-up of the upper part with its upper end shown without the cover sheet, fig. 3 shows a perspective view of a circuit board for the handset shown with five rows of switches, of which only the three upper rows are used in the example concerned, fig. 4 shows a perspective view of a blocking means seen from above, and fig. 5 shows a perspective view of a spanner for the handset.

The exemplary embodiment concerns a handset for nursing beds having an adjustable back section and leg section. Fig. 1 shows an upper part 1 for the handset which is assembled by ultrasonic welding with a lower part (not shown in the drawing). As will appear, the handset is equipped with six keys arranged in pairs, where the two upper keys 2a, 2b activate the back section and the two intermediate ones 3a, 3b the leg section. The two lower keys 4a, 4b activate the back and leg sections simultaneously. The right- hand row of keys 2a, 3a, 4a raises the sections, while the left-hand row 2b, 3b, 4b lowers the sections. The front of the upper part 1 is covered by a sheet indicating the keys.

As will appear from fig. 2, resilient portions 2'a, 2'b, 3'a, 3'b are provided as a component of the keys in the upper part below the sheet, viz. as a circular brick 5 at the end of a stem 1.

Below the keys there are small switches 7 in the form of tactile switches consisting of a brick-shaped housing 7' with a round push-button 7" on the upper side. The switches are mounted on a circuit board 8 which is mounted and secured in the lower part of the handset. A bridge element 9 is arranged above switches in pairs 2"a, 2"b; 3"a, 3"b; 4"a, 4"b, spanning from side edge to side edge on the circuit board 8 and being secured on it by a snap lock connection. The bridge elements are formed with bores 10 for the bush-buttons 7" of the switches and in the centre with a countersink 11 for the mounting of a blocking means 12, as shown in fig. 4. The bridge element is quite thin and rests directly on the upper side of the housing of the switches.

The blocking means 12 is an essentially flat element with a special recess 13 in each side. A narrow part 13' of the recess is intended for just enclosing or extending close to the push-button 7" of the switch, while an ex- panded part 13" of the recess provides a relatively great clearance around the push-button. On the centre of the blocking means 12, there is a circular elevation on the rear side which fits in the countersink 11 on the bridge element 9. The blocking means has a pivot pin 14 on the front side and an annular groove 15 at the foot thereof for a seal 16 which grips the edge of a bore in the upper part 1 , so that the upper side of the pivot pin 14 is present on the front side of the handset.

The upper side of the blocking means 12 is formed with two circular arc- shaped elevations 17', 17" arranged diametrically opposite and concentri- cally relative to the axis of rotation of the blocking means. These are seated in two corresponding circular arc-shaped recesses 18', 18" in the upper part 1 of the handset. On the elevations, there are two knobs 19, 20 with a colour indication, of which one 19 is green for non-locked key and the other 20 red for locked key. The cover sheet has a transparent section 21 so that the green knob is visible in the section when the key is non-locked, while the red knob becomes visible when the key is locked. As indicated in fig. 2, the two knobs 19, 20 may also be used for holding the blocking means in the two positions in that the recesses in the upper part are formed with a projection 22 which extends between the two knobs so that the blocking means is held by a snap connection. It is evident that one set of knobs may be omitted. In terms of production, two sets of knobs have the advantage that an orientation degree of the element may be omitted. Further, the two sets of knobs contribute to ensuring control of the element.

The blocking means 12 may be rotated by means of a spanner 24, config- ured here as a circular brick. The spanner is provided with a curved incision

25 which mates with a terminating arch of the upper side of the pivot pin. The incision of the key has two four-sided bosses 26 which fit in two correspondingly four-sided countersinks 23 on the pivot pin 14 of the blocking means. Together, this provides a safe engagement of the spanner in the axis of rotation. Of course, it may also be made differently, e.g. with a large four-sided or polygonal countersink. In e.g. fig. 3, a triangular countersink 23' is indicated. For practical storage of the spanner, it is formed with a hole 27 to allow it to be inserted into a key ring, chain or the like, or alternatively to be hung on a hook.

Claims

PATENT CLAIMS

1. An electrical handset, in particular for electrically adjustable hospital and nursing beds, comprising

a plurality of electrical switches (7; 2"a, 2"b; 3"a, 3"b; 4"a, 4"b) having an axially movable activating means (7") in a housing (7'), said activating means protruding a distance from the top of the housing,

a key (2a, 2b, 3a, 3b, 4a, 4b), likewise axially movable, provided above the activating means, which when being pushed down toward the switch steps on the activating means (7") and pushes it inwards toward the housing (7') to activate the switch, and

a blocking means (12) which may be moved from a parking position to a locked position, in which it partly rests directly or indirectly on the upper side of the housing (7') of the switch and partly serves as a stop for the overlying key (2a, 2b, 3a, 3b, 4a, 4b) at a level above the activating means (7") of the switch in the rest position.

2. A handset according to claim ^ c h a ra c t e r i z e d in that the blocking means has a recess (13) with a narrow part (13') which is just capable of accommodating the activating means (7"), and an expanded part (13") which allows passage of the key (2a, 2b, 3a, 3b, 4a, 4b) to affect the activating means.

3. A handset according to claim 1 or 2, characterized in that the lower side of the blocking means (12), irrespective of its position, rests directly or indirectly on the upper side of the housing (7') of the switch.

4. A handset according to claim 3, characterized in that it includes a bridge element (9) which, with a plane part, rests directly on the upper side of the housing (7') of the switch, and which is formed with a bore for the activating means (7") of the switch which protrudes above the plane part at least by a height corresponding to its travel, and that the bridge ele- ment is secured to the substrate (8) which carries the switches (7).

5. A handset according to one of claims 1 to 4, characterized in that the blocking means (12) is configured as a slide element slidable in the axial direction between the non-locked position and the locked position.

6. A handset according to one of claims 1 to 4, characterized in that the blocking means (12) is constructed to be rotatable between the non-locked position and the locked position.

7. A handset according to one of claims 1 to 6, characterized in that the blocking means (12) comprises a flat or essentially flat sub-element with recesses (13) for two adjacent switches (2"a, 2"b; 3"a, 3"b; 4"a, 4"b) and with a pivot pin (14) disposed between the two recesses, said pivot pin extending out on the front side of the handset between two keys (2a, 2b; 3a, 3b; 4a, 4b), the upper side of the pivot pin being configured for non- rotational reception of the end of a spanner for rotating the blocking means between the non-locked position and the locked position.

8. A handset according to claim 7, characterized in that the flat sub-element is formed with a groove (15) up to the pivot pin for a seal (16) for sealing engagement with the upper part (1) of the handset.

9. A handset according to claim 6 or 7, characterized in that snap locking means (22) are provided between the blocking means (12) and the housing of the handset for releasable securing of the blocking means at least in its locked position.

10. A handset according to claim .. characterized in that the blocking means is provided with at least an indicator (19, 20), which becomes visible in a window (21) in the upper part (1) when the blocking means is caused to assume the locked position.

11. A handset according to claim 7, ch a racterized in that the spanner is configured as a brick (24) with a curved incision (25) fitting the upper side of the pivot pin (14), and that projections (26) are provided in the incision for engagement with corresponding recesses in the upper side of the pivot pin.

12. A handset according to claim 11, characterized in that the spanner is provided with an eye (27) for the storage of it.