Bed signalling apparatus

Claim 2

A sensor, comprising: resilient means through which fluid under pressure can flow from an inlet for said resilient means to an outlet for said resilient means; fluid supplying means connected to said inlet for continuously supplying fluid under pressure toward said resilient means; switching means connected between said resilient means and said fluid supplying means for controlling indicating means in response to changes in said pressure; and indicating means connected to said switching means for indicating when there has been a change in said pressure.

Claim 3

The sensor of claim 1 wherein said open outlet of said resilient means is vented to atmosphere.

Claim 4

The sensor of claim 2 wherein said fluid supplying means includes a pump having a pump outlet connected for pumping air to said inlet for said resilient means and to said switching means.

Claim 5

The sensor of claim 3 wherein said pump includes a pump inlet having a first end connected to said pump and an opposite second end vented to atmosphere.

Claim 6

The sensor of claim 4 further including an orifice positioned between said first end and said opposite second end.

Claim 7

The sensor of claim 3 wherein said switching means includes means for reducing inadvertent activation of said indicating means.

Claim 8

The sensor of claim 2 wherein said outlet includes an orifice.

Claim 9

The sensor of claim 1 wherein said fluid supplying means includes a pump having a pump outlet connected for pumping air to said inlet for said resilient means and to said switching means.

Claim 10

The sensor of claim 8 wherein said pump includes a pump inlet and further wherein said outlet of said resilient means is connected to said pump inlet.

Claim 11

The sensor of claim 9 wherein said pump inlet includes a first end connected to said pump and an opposite second end vented to atmosphere, said outlet for said resilient means being connected to said pump inlet between said first end and said opposite second end.

Claim 12

The sensor of claim 10 further including an orifice positioned between said opposite second end and said outlet for said resilient means.

Claim 13

The sensor of claim 9 wherein said switching means includes means for reducing inadvertent activation of said indicating means.

Claim 14

The sensor of claim 1 wherein said switching means includes normally closed contacts.

Claim 15

The sensor of claim 1 wherein said switching means includes normally open contacts.

Claim 16

The sensor of claim 1 wherein said switching means includes a plurality of contact means each of which is electrically connected to a respective indicating means.

Claim 17

The sensor of claim 15 wherein each contact means includes normally open contacts.

Claim 18

The sensor of claim 15 wherein each contact means includes normally closed contacts.

Claim 19

The sensor of claim 15 wherein at least one of said contact means includes normally open contacts and further wherein at least another of said contact means includes normally closed contacts.

Claim 20

The sensor of claim 18 wherein said switching means includes means for reducing inadvertent activation of said indicating means.

Claim 21

The sensor of claim 1 wherein said fluid supplying means includes a plurality of fluid supply outlets and further wherein said resilient means includes a plurality of resilient means each of which includes a respective inlet and a respective open outlet, each fluid supply outlet being connected to a respective inlet.

Claim 22

The sensor of claim 20 further including a plurality of switching means, each switching means of said plurality of switching means being connected between a respective fluid supply outlet and a respective inlet.

Claim 23

The sensor of claim 21 further including a plurality of indicating means, each indicating means of said plurality of indicating means being connected to a respective switching means.

Claim 24

The sensor of claim 22 wherein at least one of said switching means includes normally open contacts and further wherein at least one other of said switching means includes normally closed contacts.

Claim 25

The sensor of claim 22 wherein said fluid supply outlets include at least one fluid supply outlet which functions independently of at least one other fluid supply outlet.

Claim 26

The sensor of claim 24 wherein said at least one fluid supply outlet supplies fluid to control activation of a switching means having normally closed contacts and at least one other of said fluid supply outlets supplies fluid to control activation of a switching means having normally open contacts.

Claim 27

The sensor of claim 22 wherein said switching means includes means for reducing inadvertent activation of said indicating means.

Claim 28

The sensor of claim 20 wherein each respective outlet includes an orifice.

Claim 29

The sensor of claim 1 wherein said resilient means includes at least one serpentine oriented fluid passage.

Claim 30

The sensor of claim 1 wherein said resilient means includes a base and at least one fluid passage which is oriented in a serpentine manner in the plane of said base, and further including slits which extend through said base and are positioned between loops which form said orientation in a serpentine manner.

Claim 31

The sensor of claim 1 wherein said resilient means includes a plurality of fluid passages each of which includes a respective fluid passage inlet and a respective fluid passage outlet, said fluid supplying means being connected to each respective fluid passage inlet, further wherein said switching means includes a plurality of switching means each of which is connected between said fluid supplying means and a respective fluid passage, and further wherein said indicating means includes a plurality of indicating means each of which is connected to a respective switching means.

Claim 32

The sensor of claim 30 further including a plurality of orifices, each orifice of said plurality of orifices being connected between said fluid supplying means and a respective switching means.

Claim 33

The sensor of claim 1 wherein said switching means includes means for reducing inadvertent activation of said indicating means.

Claim 34

A sensor, comprising: an upper surface and a lower surface of plastic film selectively heat sealed together to provide at least one continuous and collapsible fluid flow passage disposed between said upper surface and said lower surface, said at least one fluid flow passage having a fluid inlet and a fluid outlet; pressure responsive switching means in fluid communication with said at least one fluid flow passage by connection to said fluid inlet for actuating an indicating means in response to changes in pressure within said pressure responsive switching means; indicating means connected to said fluid responsive switching means for indicating when there has been a change in said pressure; and fluid supplying means including a pump having a pump outlet connected to said fluid inlet and to said pressure responsive switching means for continuously supplying fluid under pressure to said pressure responsive switching means and said at least one fluid flow passage, said fluid within said pressure responsive switching means being at a first pressure when said at least one fluid flow passage is not collapsed by the weight of a person and being at a second greater pressure when said at least one fluid flow passage is collapsed by the weight of a person.

Claim 35

A sensor, comprising: an upper surface and a lower surface of plastic film selectively heat sealed together to provide at least one continuous and collapsible fluid flow passage disposed between said upper surface and said lower surface, said at least one fluid flow passage having a fluid inlet and a fluid outlet; pressure responsive switching means in fluid communication with said at least one fluid flow passage by connection to said fluid inlet for actuating an indicating means in response to changes in pressure within said pressure responsive switching means; indicating means connected to said fluid responsive switching means for indicating when there has been a change in said pressure; and fluid supplying means including a pump having a pump outlet connected to said fluid inlet and to said pressure responsive switching means for continuously supplying fluid under pressure to said pressure responsive switching means and said at least one fluid flow passage, said fluid within said pressure responsive switching means being at a first pressure when said at least one fluid flow passage is not collapsed by the weight of a person and being at a second greater pressure when said at least one fluid flow passage is collapsed by the weight of a person.