US2855921A

US2855921A - Gas operated drive for rocking bed

Info

Publication number: US2855921A
Application number: US663772A
Authority: US
Inventors: James R Grosholz
Original assignee: Air Shields Inc
Current assignee: Air Shields Inc
Priority date: 1957-06-05
Filing date: 1957-06-05
Publication date: 1958-10-14
Anticipated expiration: 1975-10-14

Description

Oct. m, 1958 5. Sheet s-Shee t 1 Filed June 5, 1957 INVENTGK m 6 A! Oct. 14, 1958 J. RQGROSHOLZ GAS OPERATED DRIVE FOR nocxmc BED 5 Sheets-Sheet 2 Filed June 5, 1957 int: :;:::11

mvnvrax ATTQRNEY Oct. M, 1958 J. R. G R OSHOLZ.

GAS OPERATED DRIVE FO R ROCKING BED 5 Sheets-Sheet 3 Filed June 5, 1957 J. R. GROSHOLZ GAS OPERATED DRIVE FOR ROCKING BED Oct. 14, 1958 5 Sheets-Sheet 4 Filed June 5, 1957 I 1 1 l Ill luvs/Wm J. R. GROSHOLZ 2,855,921

GAS OPERATED DRIVE FOR ROCKING BED Oct. *14, 1958 5 Sheets-Sheet 5 Filed June 5. 1957 States Unite James R. Groshoiz, Wayne, Pa, assignor to Air-Shields, Inc., Hatboro, Pa., a corporation of Delaware Application June 5, 1957, Serial No. 663,772

12 Claims. (Cl. 128-28) This invention relates to rocking bed devces suitable for use with infants and is particularly concerned with improvements in driving mechanism for use therewith.

Rocking beds of the type with which the present invention is concerned are used in the treatment of ailments relating to the circulatory and respiratory systems. The rocking motion of the bed produces displacement of the internal organs in a fashion which causes alternate compression and distention of the lungs, thereby assisting the breathing function. The alternate raising and lowering of different parts of the body also produces a pressure change effect which assists in blood circulation.

With very young infants it is often desirable to keep them in an incubator to control their environment including the provision of an air supply having proper temperature and humidity. Often infants having deficiencies which require confinement in an incubator device will also be benefited by the use of a rocking bed device. It it therefore an important object of the invention to provide a compact rocking bed incorporating a drive mechanism which may be inserted as a complete unit in a baby incubator.

In a drive for rocking a bed device of this nature, it is desirable to incorporate a system which is not only reliable but which eliminates electric motors or conductors which might be dangerous for use in an enclosed atmosphere often having high concentrations of oxygen. It is therefore an object of the present invention to provide a drive mechanism which utilizes a supply of gas under pressure to produce the rocking bed motions. With the system of the present invention the only connections from the inside of the incubator to the outside are two tubes, one of which supplies the compressed gas for energizing the drive and the other of which conveys the exhaust gas from the apparatus to the outside of the incubator.

A further object of the invention is to provide a simple low pressure piston drive mechanism for actuating the rocking bed with an automatic return thus requiring a connection for gas to one end only of the operating cylinder. Such mechanism protects the operator and equipment in case of accident.

An additional object of the invention is the provision of a relay system for the control of the gas supply which provides for accurate control of the delivery of air to the cylinder, as well as the control of the exhaust from the cylinder.

Another object of the invention is the provision of simple mechanism for controlling both the amplitude of rocking motion and the frequency thereof. To accomplish the amplitude adjustment linkage is provided which may be adjusted to change the position at which the relay valve is opened or closed. The frequency of the rocking action is controlled by a manual needle valve to control the rate of entry or exhaust of air from the cylinder.

Still another object of the invention is the provision of an improved flexible diaphragm valve device in combination with the relay valve for providing accurate and reliable delivery and control of air to and from the actuating cylinder.

How the foregoing and other objects and advantages of the invention are attained will be clear from the following description of the drawings in which Figure 1 is a plan view of the rocking bed unit of the present invention.

Figure 2 is a side elevational view showing the bed supported in position on the floor of a baby incubator.

Figure 3 is an enlarged view of the driving cylinder and piston with the connections to the rocking bed.

Figure 4 is a sectional view taken in the direction of arrows 44, Figure 3, showing the valve connections.

Figure 5 is a sectional view through the apparatus taken generally in the direction of arrows 5-5, Figure 3.

Figure 6 is a sectional view taken in the direction of arrows 6-6, Figure 5, showing parts of the diaphragm valve.

Figure 7 is a sectional view through-the valve structure taken in the direction of arrows 77, Figure 5.

Figure 8 is a view of the internal valve structure taken in the direction of arrows 8-8, Figure 5.

Figure 9 is a sectional view through the valve structure taken in the direction of arrows 9-9, Figure 6.

Figure 10 is another sectional view through the valve taken in the direction of arrows 10-10, Figure 6.

Figure 11 is an elevational view somewhat similar to Figure 3 but showing the piston and connecting parts in a different driving position.

Referring to the figures it will be seen that in Figures 1 and 2, a bed member 15 is shown supported by pedestal structure 16 at one side and 17 at the other side of the bed member 15. The pedestal structures 16 and 17 support the bed member 15 on pivot 18 about which the rocking action occurs. The pedestal structure extends to the base plate 19 on which the complete rocking bed assembly is mounted. As indicated in Figure 2 the rocking bed unit may be placed inside an infant incubator one of the transparent canopy walls 24) being shown. The plate 19 of the bed assembly as shown in Figure 2 is supported on the floor 21 of the occupants compartment.

The bed member 15 is provided with a mattress 22 on which an infant may be supported as indicated by dotted outline 22. To support the occupant in position during rocking motion the bed may be provided with suitable positioning apparatus including the diaper-like garment 24 which is retained by central strap 25 and diagonal straps 26. Additional positioning apparatus is illustrated in contact with the upper portion of the occupants body where padded cylinders 27 are shown at each side supported by adjustable arms 28. This positioning apparatus is not part of the present invention per se, and is shown and described more fully in my copending application Seriai No. 663,728, filed June 5, 1957.

In Figure 2 the bed member 15 is shown in full lines at one extreme position. The neutral position is shown at 15a and the other extreme position at 15b in broken outline. A rod member 29 which normally lies parallel to the side of bed member 15 may be swung down and clamped in the position shown by broken outline 29a to support the bed member 15 in a stationary position while attention is being given the occupant. A clamping knob 30 retains the rod 29 in any position of adjustment.

As will also be seen in Figure 2 an arm 31 is shown connected to the pivot 18 to transmit the swinging motion of the bed. The arm 31 is connected at its lower end by a pivot 32 to a connecting rod 33 which extends to a piston 34 mounted in a cylinder 35. The arm 31 is shown in the opposite extreme position at 3%. the position corresponding to bed position 15b.

The drive mechanism will be more clearly seen by reference to Figures 3, 4 and 5. In Figure 3 the bed member 15 is in an extreme position with the piston 34 at the end of the stroke. In the position shown the piston 34 is ready to receive gas under pressure to force it to the opposite end of the cylinder 35. The connecting rod 33 is provided with a conical end 36 which engages a depression 37 in the internal piston part 38 thereby providing self alignment of the piston rod to take care of the swinging motion of the end connected to the arm 31. To prevent separation of the piston rod 33 from the piston 34, flanges 39 are provided on the piston rod 33 to engage the internal flange 40 of the piston. A helical spring 41 encircles the piston rod .33 and reacts at one end against the cylinder housing 42 and the other end against the disc 43 which transfers the spring force to cause the piston return.

The pedestal structure 16 which supports the bed pivot 18 also serves as a housing to enclose the swinging arm 31 and other parts used in the control of the actuating mechanism. A cover plate 44 is shown in Figure to enclose the mechanism in the pedestal 16. In Figure 3 the cover is shown removed to show the internal mechanism. In Figures 3 and 5 a bracket 45 is shown supported on the pedestal structure 16 by means of screws 46. At the lower end of the bracket 45 a threaded rod 47 is supported, one end of the rod extending through the bracket and being equipped with a knurled knob 43 accessible to the outside of the pedestal 16 for adjustment purposes. The threaded rod 47 has a right hand thread at one end and the other end has a left hand thread. Engaging the rod are blocks 49 and 58 having female threads to fit the right and left hand threads of the rod. Link members 51 and 52 are pivoted at 53 and 54 to blocks 49 and 50. Links 51 and 52 extend upwardly and are joined at their upper ends by means of a generally horizontal link 55 which is pivotally connected to links 51 and 52 by pivots 56 and 57.

This linkage forms a linkage system having the bottom ends of the upright links 51 and 52 movable toward and away from each other to change the spacing between them. A rod member 58 is attached to the arm 31 and extends so that the end of the rod 58 can engage the inner edges of the links 51 and 52 at certain positions of travel of the arm 31. Thus in the position shown in Figure 3 the rod 58 has contacted the link 51 and moved it to the position illustrated. In this position the upper end of link 51 engages the bracket 45. This is the extreme position of travel for the link and also the arm 31. By rotation of the knob 48 the bottom ends of the links 51 and 52 may be moved toward each other'with the result that the distance between the two links at the point of contact with the rod 58 is reduced. This reduced distance results in arm 31 being stopped in its swinging movement at a point making a smaller angle with the vertical which results in a reduced angle of swing.

When the arm 31 moves the link 51 to the position illustrated in Figure 3, a toggle linkage is also actuated. The horizontal link 55 has a pivot member 59 which engages a link 60 by means of slot 61. The link 60 is pivoted to the bracket 45 by a pivot 62. The lower end of the link 60 is connected by pivot 63 to a spring loaded slide link 64 which in .turn is pivoted at 65 to the bracket 45. With this spring loaded toggle mechanism, the bar linkage system is held in the position shown in Figure 3 until the linkage is forcibly moved in the opposite direction against the pressure of the spring loaded link 64, at which time the toggle linkage will move dead center over to the opposite side and hold the linkage in its opposite position. This opposite position of the mechanism is shown in Figure 11 where it will be seen that the piston 34, the rod 33 and the arm 31 are in their opposite 4 extreme position as compared to the position shown in Figure 3.

As will be observed in Figures 3, 5 and 11 a pin 66 extends from the link 60 and engages a lost motion arm 67 which is also attached by the pivot 62. A circular opening 68 in the arm 67 is engaged by the pin 66 and thus the arm 67 is moved when the toggle link 60 moves. However, the amplitude of movement of the arm 67 is less than the link 60 because of the lost motion developed between the pin 66 and the circular opening 68.

A shoulder 69 in the upper part of arm 67 can engage the flat spring member 70 so that when the toggle linkage is swung to the position shown in Figure ll, it moves the spring member 70 away from a small nozzle 71. It is the opening and closing the nozzle 70 which produces the feedback signal to control the flow of gas to the actuating cylinder to rock the bed.

The nozzle 71 is connected to the end of a tube 72 (see particularly Figures 1 and 5) which leads to ,a control valve device 73 which is supported on the pedestal 17. In addition to the sectional view of the control device shown in Figure 5, details of construction are shown in Figures 6 to 1.0 inclusive. The feed-back tube 72 is attached by means of a connector fitting 74 to the control device 73. Another tube 75 runs between the cylinder 35 and the control device 73, being connected to the control device by a fitting 76. The pressure gas is delivered to the control device 73 by means of a fitting 77 and a tube '78. while the exhaust from the control device 73 is through a fitting 79 and another tube v8t). The supply tube 78 and the exhaust tube 80 extend to a point outside the occupants compartment when the rocking bed is being used inside an incubator or similar enclosure.

The control device 73 is composed of three main body parts, namely, a base part 81, an intermediate part 82 an outer portion 83. i The supply fitting 77, the cylinder line fitting 76 and the exhaust fitting 79 are all connected into the body base part .81. The supply fitting 77 is connected by means of a channel 84 to a small valve cavity 85. The cavity 85 is separated from another chamber 86 by means of the spring-loaded check valve 87. One side of chamber 86 is formed by a flexible diaphragm 88 which is supported between the

body parts

81 and 82. Similarly another flexible diaphragm 89 is supported between the

body parts

82 and 83. These two diaphragms are supported in substantially parallel relationship, thus forming an intermediate chamber between the two

diaphragms

88 and 89. It will be noted that the diaphragms are retained in proper relative position by means of a structure 90 which incorporates adisc portion 81 fastened to the diaphragm 89 and which also acts as a limit stop against the flange portion of the intermediate body part 82. In addition the diaphragm structure 90 incorporates a cylindrical extension 92 which incorporates a channel within it leading from chamber 86 to the intermediate chamber 93 between the diaphragms (see Figure 9). The extension 92 of the diaphragm structure is proportioned to engage the check valve 87 and open it when the diaphragm unit is moved to the position shown in Figure 10. When in this position the channel through the structural part 90 to the intermediate chamber is closed by engagement with the valve 87. It should be noted that the exhaust tube 80 and the fitting 79 are connected by means of

channels

94 and 95 with the intermediate chamber 93. (See Figures 7 and 9.) Figures 9 and 10 show that the tube 75 to the cylinder 35 is connected to the chamber 86 by means .of a channel 96.

In the outer body part 83 another chamber 97 is formed to which is connected the feed-back tube 72 through connector 74. A small diameter orifice 98 which is best in Figure 10 connects the chamber 97 with the supply channel 84. The dilferent parts of the body are retained in position by bolts 99 as indicated in Figures 5 to 8 inelusive.

'Figures 3 and 4 show the manner in which the gas supplied through the tube 75 is delivered to the cylinder 35. The cylinder 35 incorporates a block member 100 at its outer end through which a channel 101 leads from the inside of cylinder 35 to a valve chamber 102. A valve having an external knob 103 and a tapered needle 104 is supported in the valve chamber 102 by means of the threaded shank 105. A fitting connection 106 in the block member 100 serves to connect the delivery tube 75. A channel 107 leads the gas from tube 75 into the valve chamber 102.

With the occupant retained in position on the bed, the operation of the bed is started by opening a suitable valve (not shown) located in the supply line 78, preferably outside the occupants compartment. With the rod member 29 stowed in folded position the piston return spring 41 causes the piston and bed to assume the position shown in Figure 3. In this position the nozzle 71 is closed so that as soon as the supply of gas is turned on gas under pressure will bleed through the orifice 98 into the control chamber 97 where pressure builds up to move the diaphragm to the valve open position shown in Figure 10. In this position the check valve 87 is opened and pressure gas enters chamber 86 where it can flow out through channel 96, connecting tube 75 and through the valve chamber 102 and channel 101 to the interior of the cylinder. There the supply of gas under pressure acts to move piston 34 to the right as shown in Figure 3 compressing the spring 41 and swinging the bed from the position shown in Figure 3 to the full line position shown in Figure 2.

In this position the actuating arm 31 is moved to the position shown in Figure 11 in which position the rod member 58 attached to arm 31 has contacted the control link 52 and shifted the linkage from the position shown in Figure 3 to the position shown in Figure 11. The link 60 is carried with the link system 51, 52 and as it reaches the position shown in Figure 11, the pin 66 engages the opening 68 in the lost motion link 67 to move it to the position shown in Figure 11. At this point the flat spring member 70 is moved away from the nozzle 71 permitting gas to bleed out of the nozzle and thus allow the pressure in the control chamber 97 to drop since it is connected to the nozzle 71 by means of the tube 72. As soon as the pressure in the chamber 97 drops, the pressure in chamber 86 acts to move the diaphragm assembly from the position in Figure to the position in Figure 9 thereby permitting the check valve 87 to close and shut off the supply of gas under pressure to the chamber 86 and thus to the cylinder 35. When the diaphragm assembly moves to the position in Figure 9 the channel in the diaphragm structure 90 connects the chamber 86 to the intermediate or internal chamber 93 which in turn is connected to atmospheric pressure through

channels

95, 96 and the exhaust tube 80. As a result the pressure of the return spring 41 causes the piston 34 to move back toward the starting point and forces the gas out of the cylinder through the exhaust tube.

Release of the gas from the cylinder 35 causes motion of the bed back toward the position shown in Figure 3. As the arm 31 approaches the position shown the rod 58 engages the link 51 and during the last portion of the stroke moves it into the position illustrated in Figure 3. Just before it reaches this point the link 60 moves to a position where the pin 66 engages the lost motion opening 68 in the arm 67 and permits it to snap to the position where the fiat spring 70 again closes the opening from nozzle 71. It will be noted that the dead center toggle linkage connected to the link 60, namely the spring loaded link 64 serves to hold the linkage 51 and 52 in either extreme position until the arm 31 has moved nearly to its extreme travel position when the rod 58 causes the linkage to be reversed and held in its reversed position by the toggle.

By adjusting the valve handle 103, the tapered valve needle 102, can vary the opening through which the gas flows to and from the cylinder 35. Control of the rate of flow controls the length of time required for the piston stroke in either direction and thus provides the adjustment for the rocking frequency. The adjustment for the amplitude of rocking is through the knob 48 which permits changing the distance between the bottom ends of the links 51 and 52. This changes the position of these links at which the arm 31 and the rod 58 make contact to open or close the nozzle 71. Thus the amplitude of rocking motion may be varied within limits to provide the desired angle of operation.

From the foregoing description it will be seen that I have provided a rocking bed and drive construction suitable for operation from a supply of compressed gas. By utilizing a stored energy element the rocking operation may be accomplished with a piston which is single acting with respect to pressure operation. This type of operation permits the control of the gas flow by a relatively simple valve control device and further permits the use of a simple metering valve to control the airflow in a manner which gives accurate adjustment of the rocking frequency. By the use of a feed-back signal accurate controlof the compressed gas supply to the operating cylinder is maintained. This feed-back system further provides the opportunity for use of a simple adjustable linkage which will control the length of the piston stroke and thus the amplitude of oscillation of the bed. The use of low pressure gas, such as 15 p. s. i., ensures that stalling will occur immediately in the event the op-' erators hand or other object should interfere with normal operation.

I claim:

1. A rocking bed having a transverse mounting pivot member, driving mechanism for rocking the bed including a cylinder and a piston having connecting means to said bed, a gas delivery channel extending to said cylinder, a valve inserted in said channel for alternately connecting said cylinder to a source of gas under pressure and to the atmosphere, a control system for said valve including linkage and a linkage engaging element actuated by said piston.

2. A construction according to claim 1 in which said linkage includes a pivotally mounted arm, an over-deadcenter mechanism connected to said arm to hold it in either of two positions.

3. A construction according to claim 1 in which an adjustment is provided to change the relationship of said linkage and said engaging element.

4. A construction according to claim 1 in which said gas delivery channel incorporates an adjustable valve to vary the rate of flow to said cylinder.

5. A construction according to claim 1 in which said valve control system includes a relief nozzle member, a feedback signal channel extending from said valve to said relief nozzle member, means for interrupting the flow from said nozzle member, said linkage controlling said interrupting means to provide opening and closing of said nozzle member.

6. A construction according to claim 1 in which said valve includes a body having a pressure gas connection, a connection from the cylinder channel and a connection for a feedback signal, said body having a pair of parallel interconnected diaphragms forming an outer chamber, an inner chamber and an intermediate chamber, said pressure gas connection being connected to the inner chamber by a movable valve member controlled by the diaphragms, said pressure gas connection also being connected to said outer chamber by a small bleeder channel, said feedback signal connection being to said outer chamher, said intermediate chamber having a channel leading to the outside atmosphere, the structure interconnecting the diaphragms having a channel therein which connects the intermediate chamber with the inner chamber when the diaphragms are in position to allow said movable valve member to close said innench'amber from said pressure gas connection.

7. A construction according t'o= claim 1 in which said bed is supported by twopede'sta'l' members, one at each side of the bed, one of said pedestal members housing at least a portion of the driving mechanism and the other of said pedestal housing saidvalve: I

8; A- rocking bed having a transverse rocking pivot member, an actuating arm connected to said bed, a; cylinder and a pressure operated piston, a connection between said piston and said arm, a spring connected to move said arm in the direction opposite to the pressure movement of said piston, a gas delivery channel leading to said cylinder, a valve in said channel for alternately connecting said cylinder to a source of gas under pressure and then to atmosphere, control mechanism for actuating said valve having an operating linkage engageable with said arm;

9'. A rocking bed assembly suitable for infants including a base plate, a pair of upright supporting pedestals attached to said plate, a bed supported by pivots connected to the upper portion of said pedestals, a cylinder and piston unit located adjacent to one of said pedestals, an interconnecting drive extending between said piston and said bed, a portion of said drive being housed in said pedestal, and control mechanism for delivering the power to said cylinder housed in the other of said pedestals.

10. A rocking bed construction having driving mechanism' including a cylinder and piston, actuating means between said piston and said bed, a delivery channel to said cylinder for supplying gas under pressure, a control valve connected into said channel for alternately directing gas to and from said cylinder, said valve incorporating two parallel diaphragms forming an assembly, a structure connecting said diaphragrns to cause inter-related movement, a plurality of chambers in said valve including a central chamber between the diaphragms and two outside chambers, one on each side of said diaphragm assembly, said diaphragm inter-connecting structure incorporating a channel leading from one of the outer chambers to the central chamber, a check valve to control the admittance of pressurized gas to said outer chamber, said diaphragm structure extending to engage said check valve to cause it to open and admit pressure gas to said outer chamber in oneposition of the diaphragm assembly, said structure disengaging from said check valve topermit said valve to=close when said diaphragm assembly is in the opposite position, said central chamber being connected to atmospheric pressure, a bleed connection between the incoming. pressurized gas and the other outer chamber, said other chamber also having an outlet channel to permit periodic reduction of pressure to control the position of said diaphragm assembly.

11. A rocking bed device having driving mechanism including a cylinder, a piston therein operable by gas under pressure, a channel for delivering gas to and exhausting gas from said cylinder, a valve for controlling delivery of gas to said cylinder, said valve incorporating movable diaphragm means, a checkvalve, a structure connected to said diaphragm means to engage said check valve, a control chamber adjacent to said diaphragm means, a nozzle, a feed-back line extending from said chamber to said nozzle, a nozzle closing device connected to said driving mechanism, opening of said closing device releasing pressure in said diaphragm chamber to cause movement of said piston in one direction, closing of said nozzle devicecausing build-up of pressure in' said diaphragm chamber and delivery of gas to cause movement of said piston in the opposite direction.

12. A rocking bed device having driving mechanism including a cylinder and piston, driving connections between said piston and said bed, a control for supplying gas under pressure to said cylinder includinga valve and control mechanism therefor having a pair of swinging link members, aspring-loaded, dead center device connected to said links for retaining them at either extreme position of movement, one end of each of said links being supportedon an adjustment element to increase or decrease the distance between said links, a handle connected to said element to permit movement for changing the position of the mechanism at which reversal of the link members occurs.

References Cited in the file of this patent UNITED STATES PATENTS 234,061 Powell Nov. 2, 1880 1,191,772 Dickerson July 18, 1916 2,429,834 Madden et a1. Oct. 28, 1947