US 3345985 A
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L. FISHER HOSPITAL BED WITH PRESSURE CHAMBER Oct. 10, 1967 4 Sheets-Sheet 1 Filed June 10, 1964 wail i Oct. 10, 1967 FISHER HOSPITAL BED WITH PRESSURE CHAMBER 4 Sheets-Shed 2 Filed June 10, 1964 Oct; 10, 1967 L. FISHER 3,345,935
HOSPITAL BED WITH PRESSURE CHAMBER Filed June 10, 1964 4 Sheetsheet 3 Oct. 10, 1967 F|SHER HOSPITAL BED WITH PRESSURE CHAMBER Filed June 10. 1964 4 Sheets-Sheet 4 United States Patent 3,345,985 HOSPITAL BED WITH PRESSURE CHAMBER Leonard Fisher, Farnborough, England, assignor to Vickers LimitetLLondon, England, a British company Filed June 10, 1964, Ser. No. 373,984 Claims priority, application Great Britain, June 17, 1963, 24,114/ 63 3 Claims. (Cl. 128-204) This invention relates to hospital beds.
According to the present invention there is provided a hospital bed for treatment of patients at pressures other than atmospheric, the bed comprising an upper part and a lower part, and means for sealing the upper part to the lower part, the parts when sealed together forming a closed chamber in which a patient can receive treatment, the upper part having a transparent portion for enabling a patient sealed in the bed to see out and there being an inlet through one of the parts for the introduction of gas into said chamber.
For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
FIGURE 1 is a side elevational view of a hospital bed,
FIGURE 2 is an end elevational view of the head of the bed,
FIGURE 3 is a perspective view from above and t one side of the foot of the bed,
FIGURE 4 is a side view, partly in section and to an enlarged scale, of part of the foot of the bed,
FIGURE 5 is a plan view, partly in section and to an enlarged scale, of one side of the head of the bed,
FIGURE 6 is a cross-section of part of the peripheral portion of part of the bed, and
FIGURE 7 is a circuit diagram of a warning device incorporated in the bed. The hospital bed has a lower part 1 in the form of an elongated shallow bowl in which a mattress may be fitted for receiving the patient to be treated. The lower part 1 is pivotally mounted, about a transverse horizontal axis 2 at or near the middle of the bed, on a cradle 3, substantially H-shaped in plan, fitted with castors 4 to enable the whole bed to be moved easily. The mounting of the lower part 1 on the cradle 3 is by means of trunnions 5 carried by bearings 6 at the top of supports 7 one at each side of the cradle 3. The tilt of the lower part 1 relative to the cradle 3 is controllable by a hydraulic jack 8 connected between the central part of the cradle 3 and the underside of the lower part 1. The jack 8 is inclined with respect to the horizontal and has an arm 9 pivotally attached to a projection 10 on the underside of the lower part 1 and a cylinder 11 pivotally attached to a projection 12 on a central cross member 13 of the cradle 3. Fluid for the jack 8 is supplied through a flexible pipe 14 to the cylinder 11 from a pump 15 mounted on the outside of thecradle. The pump 15 has an operating handle 16 and a fluid cylinder 17. The jack 8 and the frictional resistance of the bearings 6 on the hinged to the lower part 1 at the end remote from the dome 19 about an axis 20 parallel to the axis 2. The hinge arrangement includes two longitudinally extending arms 21 attached one on each side of the bed to the upper part 18 by gussets 22 and extending from the dome 19 to overhang the foot of the bed in downwardly extending cheeks 23. The lower part 1 has a bracket in the form of two arms 24 whose ends are adjacent and laterally inside the cheeks 23 and are joined by a curved plate 25, centred on the axis 20, extending across the foot of the bed. A hinge or axle 26, whose axis is the axis 20, extends through the cheeks 23 and the arms 24, and a rod 27, parallel to the axis 20 and having an axis lying in a plane tangential to an intermediate part of the plate 25 when the parts 1 and 18 are closed together, joins the arms 21 above the end of the upper part 18 at the foot of the bed. Laminated springs 28 each have one end fixed to the lower edge of the plate 25 and the other end hooked around the rod 27. These springs 28 are arranged in a series across the bed, for example twelve may be provided, and a cover 29 hinged on the rod 27 normally conceals them. An arm 30 pivoted at one end to one of the arms 21 has its other end formed with a slot in which a stud 31 on the adjacent arm 24 engages to limit upward hinging movement of the upper part'18.
An endless strap 32 is arranged around the rim of the lower part 1 and has a portion 33 extending along each of the two sides of the lower part 1 and a curved end portion 34 extending around each of the two ends of the lower part 1, each adjacent pair of strap portions 33, 34 being joined by a link 35. One end of one side strap portion 33 has an outwardly projecting boss 36 formed with a horizontal screw-threaded bore. A rod 37, screwthreaded at one end is carried for free rotation but no axial movement on a bracket 38 fixed to the lower part 1 and has its screw-threaded end engaged in the bore of trunnions 5 are suflicient to maintain the lower part 1 in any desired tilted position, once the pump ceases to be operated, without any clamping device being necessary.
The bed also has an upper part 18 which is in the form of an inverted elongated shallow bowl, complementary to the lower part, having at one end thereof a transparent dome 19. The upper part 18 and the dome 19 are shaped to allow a patient in the bed to adopt a reclining position when the parts are closed together, the patients head being within the lower part of the dome so that the patient can see out. The upper part 18 is the boss 36. The rod 37 is rotatable by a handle 39 acting through bevel gears (not shown) in a casing 40 fixed to the lower part 1. Rotation of the handle 39 causes, through the screw action of the rod 37 in the boss 36, displacement of the strap 32 around the rim of the lower part 1. The boss 36, the rod 37 and the bracket 38 are concealed by an extension of the casing 40 which extension has on its upper surface two marks with which a mark on a lug 41 on the strap 32 co-operates to indicate locked or unlocked, as explained below. Each portion 33, 34 of the strap 32 is of U-shaped cross-section with the limbs of the U horizontal and extending inwardly with respect to the bed. The horizontal upper limb of each portion has its inner edge castellated. The rim of the lower part 1 of the bed has thereon an outwardly directed rib 42 on which are formed lugs 43 spaced apart at regular intervals around the bed. The castellations of the strap 32 cover the lugs 43, engaging the sides of the lugs 43 facing the upper part 18, when the strap 32 is in a non-locking position relative to the lower part 1. The horizontal lower limb of each strap portion 33, 34 engages underneath the rib 42, ie the side thereof facing away from the upper part 18. The rim of the upper part of the bed also has lugs 44 which are complementary to the lugs 43 on the lower part and which move to engage between the latter as the two parts 1 and 18 are closed together with the strap 32 in said non-locking position. The lower part 1 of the bed has around its rim immediately inside the lugs 43 a shallow groove 45 in which is disposed an O-ring seal 46 that projects from the groove 45. When the two parts are closed together the strap 32 is free to be displaced around the rims by rotation of the handle 39 so that the castellations at least partly cover or engage the sides of the lugs 44 facing away from the lower part 1 in the locked position of the strap 32, progressive displacement of the strap 32 from said non-locking position forcing the lugs 44 on the upper part 18 progressively harder against the rib 42 on the lower part 1, thereby clamping the two parts 1 and 18 together to form a sealed chamber.
A warning device (FIG. 7) is rovided to guard against the bed being closed when the strap 32 is inadvertently in the locking position. This device includes a flashing light 47 on the casing 40 in series with a microswitch 48, mounted on one of the arms 21 (FIG. 1) and arranged to be operated by contact with the strap 32 upon the bed being closed, a further microswitch 49, fitted to the lower part 1 and arranged to be operated by a block 50 on the strap 32, and a battery 51. The switch 48 is closed when the upper part 1 is raised and the switch 49 is closed when the strap 32 is in the locking position so that the warning light 47 flashes in that condition of the bed.
Inlet and exhaust pipes 52, 53 for gas, oxygen for example, under which a patient is to be treated lead into and from the lower part 1. The inlet pipe is branched at 52A, 52B and leads into the bed behind a back rest 54 for the patient. The outlet pipe 53 terminates in a fish tail 55 opening into the bed near the foot thereof but is brought out of the bed near the inlet pipe 52. The pipes 52, 53 are flexible outside the bed and lead to a mobile cabinet (not shown) containing controls and gauges by means of which an attendant may adjust or check the pressure, humidity, temperature and purity of the gas in the sealed chamber formed by the clamped together upper and lower parts. The bed may form part of a closed circuit, exhaust gases from the pipe 53 being reconditioned and returned to the pipe 52. Windows 56 are provided in the upper part 18 for enabling an attendant to view parts of the patient undergoing treatment and both parts of the bed are of rigid stressed construction to withstand pressure diflerences between the sealed chamber and atmosphere. The upper part 18 of the bed is of double sheet construction to ensure lightness commensurate with strength, and a handle 57 is fixed to one side of the upper part 18 below the dome 19 to facilitate opening and closing the bed. The pump 15, the handle 39 and the handle 57 are all arranged for convenience at the dome end of the bed and on the same side of the bed.
For use of the bed, the patient is arranged on the mattress in the lower part 1 so that his or her head will lie under the transparent dome. It will be understood that the use of the back rest 54 is optional. The springs 28 maintain the upper part 18 in its uppermost raised position defined by the arm 30 while the patient is placed in the bed, but the excess torque exerted by the springs 28 over the torque due to the weight of the upper part 18 is sufliciently small to allow the latter to be pulled down by the handle 57 quite easily. When the bed is nearly closed the weight of the upper part 18 overcomes the torque of the springs 28 and the bed will close without further assistance. The upper part 18 is then sealed to the lower part by operation of the handle 39 which moves the strap 32 to the locking position, and gas is introduced to the closed chamber through the inlet pipe 52 and escapes via the pipe 53. The tilt of the bed may be altered as is convenient by operation of the jack 8 by means of the pump 15. Treatment of the patient may be at super-atmospheric or sub-atmospheric pressure. Super-atmospheric pressures employed may be up to two or three atmospheres. Upon cessation of treatment the pressure in the chamber is adjusted to atmospheric and the bed is opened by correspondingly reversed operations to those needed to close the bed.
Conveniently intercomniunieation equipment (not shown) may be provided so that attendant and patient can communicate when the patient is sealed within the chamber. In alternative arrangements (not shown) the upper part of the bed, may be hinged to the lower part about an axis along the side of the bed or the upper part may be made so that it can be lifted completely clear from the lower part.
1. In a hospital bed for treatment of patients at pressures other than atmospheric, the bed comprising a rigid lower part, a rigid upper part co-operating with the lower part to form therewith a closed chamber for totally enclosing a patient who can receive treatment therein at pressures up to three atmospheres, means for sealing and holding the two parts together, said sealing means including a strap around the peripheral portion of one of said parts and co-operating with the peripheral portion of the other part to permit the latter to be brought into closed relationship with said one part in a first position of the strap and to clamp said parts in a second position of the strap, means on the other of said parts co-operating with the strap means in its second position, means for shifting said strap around the periphery of said one part from one position to the other and vice versa, a transparent domed portion in the upper part for enabling a patient sealed in the bed to sit up and see out, and an inlet in one of said parts for the introduction of gas into said chamber.
2. A bed according to claim 1, wherein a rib extends around the peripheral portion of said one part there being, on the side of the rib facing said other part, a series of lugs spaced apart around said one part, wherein a series of lugs which are complementary to the firstmentioned series are spaced around the peripheral portion of said other part and interengage with said first-mentioned series when the parts are closed together, and wherein the strap is of U-section, one limb of the U engaging said rib on the side thereof facing away from said other part and the other limb of the U being castellated, the castellations engaging, in said first position of the strap, the sides of the lugs of said one part facing said other part and permitting engagement of the lugs of said other part between the first-mentioned lugs, and said castellations engaging, in the second position of the strap, the sides of the lugs of said other part facing away from said one part.
3. A bed according to claim 2, and further comprising a warning device for indicating when said strap is in said second position with the parts not closed together.
References Cited UNITED STATES PATENTS 1,449,940 3/1927 Hackney 292-25667 2,240,819 5/1941 Waly 128-145 2,700,384 1/1955 Ivory 12s 204 2,801,428 8/1957 Streeter 5284 X FOREIGN PATENTS 1,136,521 12/1956 France.
683,072 11/1952 Great Britain.
RICHARD A. GAUDET, Primary Examiner,
W, E Assistant Ex iner,