US3031687A

US3031687A - Oscillating bed

Info

Publication number: US3031687A
Application number: US788927A
Authority: US
Inventors: Stevens Rita Mcneil; Charles H Barnes
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-26
Filing date: 1959-01-26
Publication date: 1962-05-01
Anticipated expiration: 1979-05-01

Description

y 1962 R. MCNEIL STEVENS ETAL OSCILLATING BED 3 Sheets-Sheet 1 Filed Jan. 26, 1959 Jar/e45 M65 y 1, 1962 R. M NEIL STEVENS ETAL 3,031,687

OSCILLATING BED Filed Jan. 26, 1959 3 Sheets-Sheet 2 1 ma I f w "'w Hill nn".

CL 1 25 jW W Jmmhmw Inf/E5 INVENTORS Q74 MM/z 575757145 Canary HEW/v55 ilnited ha rcu wag lur spanner GSQEiLLAHNG BED Rita McNeil Stevens, Altarlena, (Ialif. (1621 Raymond Hill Road, South Pasadena, Qaiii}, and Charles H. Barnes, 2756 E. Glenoalrs Blvd, Glendale, Calif.

Filed Jan. 26, 1959, Ser. No. 78%,927 lit Claims. (Ci. E mi?) T he invention relates to apparatus for oscillating beds and more particularly to such apparatus for oscillating beds for infants or invalids.

No adequate mechanical substitute has been devised for manually rocking an infant to sleep. Many attempts have been made to rock mechanically cribs, cradle s, and

the like. Such attempts have not been commercially successful because of excessive cost and failure to achieve a soothing motion without undue noise.

One cost factor is the motive power for moving the bed member which supports an infant or other bed occupant. Conventional oscillating cribs have inherent inertia problems requiring an inordinate amount of power to accomplish a simple oscillating motion of the support member for the bed occupant. Previous devices have also required complicated and cumbersome guide or track arrangements with large floor space requirements. We have invented an oscillating bed which is structurally simple, requires siibstantially the same floor space as conventional cribs or beds, is relatively noiseless, and effects an oscillating motion soothing to an infant or other occupant.

The invention contemplates apparatus comprising a static frame movably mounting a mattress holder or movable framework. Preferably support pendulums pivotally suspended from the static frame at a point above the surface upon which the occupant lies support the framework. Means fixed to the had such as solenoids or rotating motors oscillate the movable framework with respect to the static frame. Springs link static and moving components to make smooth power transmission from the power source whether the source be solenoids or rotating motors. The springs absorb motor torque if the moving component of the bed is restricted. This protects bed users against injury caused by being caught between moving and non-moving parts of the bed.

The power source may be mounted to the movable framework and moved therewith. However, the electrical supply cable to the power source must then be flexibly mounted, with attendant wiring diiliculties. The preferred embodiment of the invention, therefore, has a power or motive source fixed with respect to the static frame.

In the preferred embodiment of the invention the static frame includes upright members at each of its corners which extend above the mattress holder or movable framework have pendulum pivots adjacent their upper ends. it has been found that support pendulums swinging in an arc of from to inches impart the optimum motion to the mattress holder and mattress to sooth a supported infant.

There should be synchronisrn between the natural period of oscillation of the support pendulum length selected and the cycling rate of the motive source. in the case of solenoids the cycling time of the solenoid is controlled by a limit switch contacted by the moving portion of the oscillating bed. When the motive source oscillating the bed is a rotating electric motor, the output rotation of the motor should coincide substantially with the period of the pendulum.

Because of inertial forces involved in swinging the mattress holder and its occupant (such mass may approximate pounds) it is preferable to inhibit backlash motion imposed upon the motor at the moment of oscillation reversal and at turning off the power. Two means are employed to counteract backlash. One means comprises opposed extension springs fastened at their inner ends to a drive arm at a point spaced from the center of rotation of the motive source. The other ends of the extension springs are fixed to the crib on opposite sides of the motive source. The springs are lightly preloaded so that the required starting moment is small. A second backlash inhibiting means comprises a drive wheel fixed to the rotating output shaft of the motive source and a friction brake in constant contact with the periphery of the drive wheel. The friction brake inhibits reverse rotation of the drive wheel as the Wheel takes the insertial load imposed at the end of each pendulum swing or when the drive speed is changed.

It has been found that different infants react favorably to different oscillatory periods. Therefore, it is preferable that be provided for effectively altering the length of the mattress holder support pendulums. This can be done by a sliding pivot ring about the pendulum which changes the effective pivot point of each pendulum.

Of course, altering the support pendulum length changes not only the magnitude of pendulum swing but also the period of the pendulum. Therefore, means preferably are provided to alter the speed of the power source commensurate with the change in pendulum length.

Various control means may be used to determine the time period during which the bed is oscillated. Manual switches may be provided which actuate a timer controlling the power source. However, it is preferable particularly with infants, to provide each oscillating bed with a control mechanism responsive to audible signals origi These signals may be used to mating with the occupant. initiate a timed power sequence or may merely turn the power switch to on until the switch is manually reversed.

Tests have shown that a small, infant in a disturbed state is induced to sleep in from three to eight minutes by the oscillating motion of a crib built in accordance with the invention. In the preferred embodiment of the invention the motion may be instituted without attendants by the babys cries.

These and other advantages of the invention are apparent in the following detailed description and drawings in which:

FIG. 1 is a side elevation partly broken away of a crib in accordance with the invention;

FIG. 2 is a fragmentary elevation illustrating an alternate power means for oscillating the embodiment of FIG. 1;

E6. 3 is a further embodiment of the invention utilizing a conventional baby carriage as the movable framework;

FIG. 4 is an elevational view partly broken away of an alternate embodiment of the invention provided with auditory power control means;

FIG. 5 is a transverse sectional elevation taken along line 55 of FIG. 4;

FIG. 6 is a preferred embodiment of the invention shown in side elevation and partly broken away;

assess";

FIG. 7 is a fragmentary plan view partly in section of the preferred embodiment of FIG. 6;

FIG. 8 is a fragmentary sectional elevation taken along line 8-8 of FIG. 6;

FIG. 9 is a fragmentary sectional elevation taken along line 9-47 of FIG. 6;

FIG. 10 is an enlarged detailed fragmentary elevation taken in the area Ill-1t of FIG. 6;

FIG. 11 is a perspective view of an alternate mounting means for the extension springs, to be used with the apparatus of FIG. 10;

H6. 12 is a fragmentary sectional elevation similar to FIG. 8 illustrating an alternate embodiment of the mounting means for the support pendulums; and

:FIG. 13 is a fragmentary sectional elevation similar to 'FIG. 4 and showing an alternate motive means for oscillating the bed.

In FIG. 1 a crib It) has side rails 11 and 12 spaced apart and extending between spaced end members M and 15. Each side rail may comprise an elongated panel 12A and top and bottom rails 12B and 12C, respectively. Each end member has a panel such as panel 16 of end member and vertical posts 17 extending upwardly at each side of the end members. The side rails and end members are preferably rigidly joined to form a static frame. The static frame may be mounted on casters 20 'to facilitate movement of the crib from place to place.

Each end member .post 17 has a pivot 22 extending inwardly from the post. An articulated support pendulum 24 depends from. each pivot. The support pendulum maybe of jointed material such as link chain. The pivot may be a metallic hook which is screwed into the vertical post.

In FIG. 1 only two of the four support pendulurns are visible. Thelefthand pendulum is adjacent near side rail 12., while the righthand pendulum is adjacent remote side rail 11. Each support pendulum has a vertically 'extending'shield 27 preferably fastened to the inner face of the vertical post and intervening between the support pendulum and a crib mattress 29.

Themattress is supported upon a movable framework 31 supported at each of its corners by a pendulum 24. The pendulums are fastened to the framework by means such as screw eye 33. Framework 31 is narrower and shorter than the span between the end members and the side rails, respectively. It may, therefore, swing at the end of the pendulums in the longitudinal direction.

A swinging motion is imparted to the framework and the mattress supported thereon by an electric motor 35. A mounting plate 36 fixes the electric motor on the movable framework to a vibration damping pad MA. A

drive shaft 37 of the motor rotates an eccentric arm 39.

Similar extension springs 41, 42 are fastened at the outer end of the arm. In FIG. 1 spring 41 extends leftwardly from its arm mounting point parallel to the side rails, and spring 42 extends tothe right in a similar line. Each spring is mounted at its end remote from the eccentric arm to a transverse rod 44 fastened at each of its ends .in the side rails of the static frame.

A power cord 47 connects the motor to a motor control switch 48. Preferably the control switch incorporates a timing device operable to close the switch for a predetermined length of time.

Control switch 48 is preferably actuated by a voice amplifier as which may be conveniently mounted to panel 16 of the end member adjacent the head of an occupant. The voice amplifier is connected by an electrical lead 51 to the control switch and actuates the incorporated timing device which thereby supplies power to the electrical motor in response to audible signals from the child in the crib.

The movable framework and its mattress and the electric motor move as a unit. Therefore, it is preferred thata resilient loop 53 be a part of the supply cable 47 a bracket bracket and has an orifice (not shown) through which the i to compensate for changes in the position of the electric motor.

In operation, when a crib occupant emits cries, they are picked up and amplified by voice amplifier 49. A signal from the amplifier actuates control switch 48 and starts motor 35, keeping it in operation for a predetermined time.

Motor shaft 37 rotates eccentric arm 39 about the center of rotation of the motor shaft, and extends one of the springs as it allows the other to retract. The extended spring exerts a pull upon the static frame through respective transverse rod 44. Since the static frame does not move, the resultant of this force imposes its load on the motor and movable framework. This results in relative motion between the framework and the static frame.

The extension springs are preferably preloaded to about 2 /2 pounds tension each. At this loading and with a spring length of about 2 feet, a smooth oscillating motion is imposed upon the movable framework and its mattress. The springs tend to augment the weak reversal force at the end of each eccentric arm swing so that the total movement of the framework is a smooth evenly powered oscillation.

The rotational speed of the motor drive shaft is prefcrably' synchronized with the period of the support pendulurns. The support pendulums are preferably of a bendable nature such as a link chain shown in PEG. 1. However, they ay be rigid rods or flexible cable, lengths of webbing, or even hinged flat plates.

As mentioned before, different children respond to different oscillation patterns. Therefore, it is preferable to have some means of changing the effective length of the pendulums. One such means is illustrated in FIG. 1 on one of the chains 24' fastened to end member 14. The means comprises a track or channel 55 in which 56 is slidable. An arm 5'7 extends from the support pendulum may extend. The port is small enough that the support pendulum has no freedom of motion within it. The pendulum will, therefore, tend to estabiish a pivot point within the arm rather than swing from pivot 22. In fact, the position of bracket and arm 5'7 establishes the length of the pendulum. The bracket is locked in position by means of a thumb screw 58 which bears against the back of the channel 55. Indicia on the edge of the bracket may be used to aid in setting the separate pendulums to the same length.

If the chain links are large enough, the effective penduium length and hence the period of oscillation may be changed by inserting a lower chain loop over the pivot 22 to leave a chain end such as 24A inactive above the pivot point. This arrangement is shown at end memher 15 of FIG. 1.

in PEG. 2 the power source for oscillating the movable framework is a plurality of solenoids such as the solenoid 61. Solenoid 61 is mounted to an end member 148 adjacent a pivot 22B supported by a bracket 62 extending from the end member. A rigid support pendulum 24B depends from the pivot. Similar arrangements may be provided at each corner of the bed.

An extension spring 63 connects between an armature 6d of the solenoid and the support pendulum. Each time the solenoid is actuated the armature pulls the spring and hence the pendulum toward the end member. Preferably the solenoids mounted at each end of the crib are linked in common to a power supply 65. A limit switch 66 mounted to end member 143 is contacted at the extreme of pendulum travel. When the limit switch is actuated it opens the power circuit to defeat the solenoids, enabling the kinetic energy of the movable framework to reverse the direction of swing. The solenoids at the opposite end of the bed then augment the momentum of the framework.

The limit switch may be of a type having a controlled dwell time. Thus it would not close the circuit to the solenoids until the proper moment for exerting a force on the pendulums toward end member 14B had occurred. The limit switches may be used to operate conventional relays and one may be provided at each extreme of the support pendulum swing to obviate the necessity for a switch with a built in dwell time. Many other obvious circuits can be utilized to accomplish the function illustrated by the apparatus of FIG. 2.

In FIG. 3 a movable framework which in this case comprises a conventional baby carriage '71 has the usual four wheels, 72, 72A, 73, 73A.

Wheels

72 and 72A reside in a longitudinal groove 74- of a static frame 75. A second parallel groove 76 guides wheels '73, 73A on the opposite side of the carriage, so that any movement of the carriage must be along the grooves. A single longitudinal groove may be used to guide the carriage along the static frame. In some ways this is preferable since no adjustment need be made for varying wheel spans. The wheels '72, 73 are mounted on a transverse axle '77.

Wheels

72A, 73A are similarly mounted to an axle 78. An exension spring 77A, 78A extends respectively from each] axle to an eccentric journal 79 turned by electric motor 81. In an operation similar to that described with respect to FIG. 1, rotation of the motor 81 imparts an oscillatory motion to baby carriage '71. Static frame 75 may be provided with a friction surface 32 along its bottom to preclude sliding motion of the static frame with respect to the floor when in operation.

FIG. 3 differs from the concept illustrated in FIG. 1 in that the motive source of the oscillatory motion is fixed with respect to the static frame rather than with respect to movable framework 71 and grooves guide the movable framework instead of support pendulums.

In the embodiment of FIGS. 4 and the movable framework is suspended from support pendulums. A static frame 85 has longitudinally spaced

legs

86, 87 and

uprights

88, 89 rising from

legs

86 and 87, respectively, to support a movable framework 91. A longitudinal brace 92 extends between the uprights of the static frame.

A

crossarm

94, 95 is afiixed to uprights S8, S9 respectively and extends transversely almost the full distance between a pair of spaced side rails 97, 98 of movable framework 91. A support pendulum 99 depends from each end of each crossarm. The support pendulum is a relatively wide hinge pivoted at its upper end on a line beneath the lower edge of each crossarm such as 95 and pivotally mounted to a stub rod extending inwardly from each side rail near the ends of the side rails. Thus the side rails of the movable framework are supported by the support pendulums depending from the static frame.

The side rails are rigidly fixed to a pair of spaced end members 164, 195 of the movable framework. The movable framework is in most respects similar to conventional cribs, having vertically slida-

ble side gates

107, 108 and a mattress support 169 on the side rails. A voice amplifier 1.1% may be fixed to an end member such as end member 1525 to perform the same function described in conjunction with the embodiment of FIG. 1. As seen in FIG. 5, mattress support 169 rests in a groove in each of the side rails of the movable frame. The crib mattress is shown in phantom lines in FIG. 5 supported by a plurality of springs 112 of the mattress support.

A pair of thwarts 1 14, 115 fixed at each of their ends to the side rails midway of the rails brace the side rails at their midpoints and support an electric motor 117 having a rotating drive shaft 118 to which an eccentric arm 119 is fixed. Extension springs 12.1, 122 extend in opposite directions from a pivoted outer point of the eccentric arm. The ends of the springs remote from the eccentric arm are fixed to an upright of the static frame. The motion im parted to the movable framework is similar to that described in conjunction with FIG. 1, the motor itself oscillating with the framework.

The embodiment of FIGS. 4 and 5 is more stable in its motion than the embodiment of FIG. 1. Stability is increased by the use of the hinge type support pendulums. The width of each hinge extends perpendicularly to the path of desired motion and the width thereby inhibits side sway more effectively than does the extention spring pull depended upon in the embodiment of FIG. 1. However, the period of the support pendulums of the FIG. 4 embodiment must of necessity be very short since the effective pendulum pivot line is the bottom of the crossarm below the mattress surface upon which the crib occupant lies. In order to increase the pendulum period the surface of the mattress must be raised to an impractical height.

The embodiment of FIG. 4 is susceptible to the same control means as that of FIG. 1 and is, therefore, provided with a control switch 125 which may include a timer and be actuated from voice amplifier 110, and thereby actuate and control the operation of motor 117 according to the needs of the crib occupant.

The preferred embodiment illustrated in FIGS. 6 through 10 obviates most of the difficulties encountered in previous oscillating beds. In this embodiment a crib comprises a static frame 131 in the movable framework 132. The static frame has spaced

parallel bases

134, 135 which rest on the door, preferably metal gliders. A frame upright 137 extends from each end of a base member. Preferably the uprights are angle irons turned so that the corner of the angle forms a corner of the frame. Longitudinal members 133, 139 also of angle iron extend the length of the static frame and are joined to the uprights so that an end portion 141 at each end of the longitudinal member extends beyond the respective upright. The longitudinal members are fixed to the uprights slightly below the top of the uprights. Atransverse brace 142 extends between each pair of end uprights and projects outwardly a short distance beyond each upright of a pair. An upwardly opening short channel 144 is fixed to the end outboard face of a transverse member near each juncture of that member with an upright and extends outwardly ideways alike distance beyond the upright.

The longitudinal and transverse members of the static frame arefixed to the outer surfaces of the angle'iron uprights. The uprights thereby form corner braces for these members as well as supporting them vertically.

A vertical post such as the

posts

146, 147 of FIG. 6 extends upwardly from the outer ends of the channels 144-. These posts comprise mounting means for the support pendulums. The posts are fixed to the respective channel members and are preferably of such a weight that they have a small degree of transverse flexibility with respect to the oscillating motion of the movable framework.

As is shown in more detail in FIG. 8, the top of each vertical post mounts a pivot block 149 which has a threaded vertical hole 151 and a transverse horizontal hole 152 intersecting the threaded hole. A pendulum pivot 153 which maybe a polished bolt, is slidably mounted in holel52. A flanged bushing 154 i journalled on the pivot with its flange riding against the pivot block. A thrust washer 156 is mounted about the bushing adjacent a head 153A of the pendulum pivot. An upper loop 158 of a support pendulum 159 is journalled on the bushing between the bushing fiange and thrust washer 156. The bushing is preferably of nylon so that an effective journal is formed with the polished shank of the pivot.

The support pendulum may be of wire rod or of flexible cable, depending upon requirements. Flexible cable may be preferable for reasons to be explained later with respect to FIG. 12.

Threaded hole 151 receives a bolt 162 on which a rubber rimmed nylon roller 153 is mounted. The roller is rotatably bound against a second flanged nylon bushing 164 interposed between the roller and the top of pivot block 149. Bushing 164 and roller 163 may be integral. A bolt head 165 bears against the top of the roller. The len th of the bolt and the length of the bushing are cor- 7 related so that the bolt may bind pendulum pivot 153 in place and leave a space between the flange of the bushing and the bolt head 165 such that a running fit is formed with the roller.

Each vertical post'includes the apparatus illustrated in FIG. 8 to support a support pendulum 159 depending from a pivot point thereon above the surface upon which a crib occupant lies. Each support pendulum depends to a mounting near the bottom of a pair of

side rails

171, 172 of the movable framework. The side rails extend between a pair of spaced

end members

173, 174 of the framework. The end members preferably extend from the bottom of the side rails vertically to a point above the top of rollers 163. Each end member sup ports a pair of shields like

shields

176, 177 of FIG. 7. Each shield has spaced

walls

178, 179, a top member 1'31, and an end vertical member 182. Mounting brackets 184 for a conventional mattress support frame (shown fragmentarily at 186) are fixed to each of the box shield end members. The bracket supports are fixed to the end members so that the highest mattress support position supports the mattress itself below the support pendulum pivots 153.

Conventional vertically movable side gates such as the gate 191 are also supported by the end members of the box shields. These side gates form no part of the invention, so no detailed description of them is given.

The movable framework of the embodiment of FIGS. 6 through 10 therefore comprises side rails 1'71, 172,

end members

173, 174, pairs of box shields 176, 177 and the conventional mattress support. This entire framework including the mattress supported thereby'ismovable as a unit with respect to the static frame.

The static frame in turn comprises the vertical pos ts such as

posts

146 and 147, the channels 144, Ion-gitudinal and

transverse members

138, 139 and 142 respective ly and the vertical uprights 137 extending from base members 134, 1355. Additionally, the static frame comprises a horizontal beam 191 extending from base memher to base member centrally thereof.- The beam supports an electric motor 192 which furnishes the motive power for oscillating the movable framework. The electric motor is fixed to the beam and hence fixed with respect to the static frame.

The motor has a drive shaft 195A to which a wheel disk 1% is fixed. Preferably the wheel disk has a diameter of about 5 /2" and a flat periphery 196A. A pivoting spring mount 197 extends from a face of the wheel disk remote from the motor. The mount pivots with respect to the disk. An end of each of two extension springs 193, 199 is fixed to the spring mount. Opposite ends of the extension springs are each fixed to either end member of the movable framework. The spring mount is pivotal with respect to the wheel disk so that the ends of the springs mounted thereto never cross each other.

As in the previously described embodiments, the motion imparted by the eccentrically mounted spring ends is imposed upon the movable framework. In the present embodiment the motion is a more direct resultant of the throw of the drive wheel disk since the drive motor is static. The motion, therefore, is directly transmitted through the extension springs to the movable framework. Static mounting of the motor is preferable since there is no need to provide complicated power cables to compensate for motion of the motor. I

The period during which the motor operates may be controlled in the manner described in conjunction with previous embodiments. However, in this embodiment as well as in the previously described ones, a manual switch (not shown) may be used to control the motive source.

As shown in detail in FIG. 9, the bottom end of support pendulum 159 is pivotally mounted to the side rail 171 of the movable framework. A threaded lower pivot 201 which may be a polished bolt, extends inwardly through a hole 292 drilled in the side rail near its bottom edge adjacent its joint with the end member. A plate 203 is fixed by means of a screw 204 to the inner surface of the rail. The plate has a threaded hole 203A aligned with the hole in the rail. The lower pivot makes threaded engagment with the plate hole 206A and may be locked in a selected position by a locking nut 295. A metallic washer 2% on the lower pivot bears against the outer surface of the rail. A nylon or suitable bushing Ell? journalled on the pivot has a flange 263 which bears against the washer, and neck 209 which surrounds the pivot. A bottom loop 211 of the support pendulum en circles the bushing neck. A second washer 212 adjacent head ZtlflA of the lower pivot confines the bottom loop on the nylon bushing. The friction load on the loop may be adjusted by repositioning lock nut 205 and the relation of the lower pivot to the outer face of the side rail.

At times it is advantageous to lift the crib or bed to move it. A problem is apparent, since the framework is movable with respect to the static frame. Therefore, in the embodiment of FIG. 6 means are provided for lifting the static frame by means of the movable framework so that only the movable framework need be contacted by the movers. When the movable frameworkis lifted,

the upper surfaces of side rails 17 ll, 172 Contact the bottom surfaces of transverse static frame members 142. Thus the entire crib including the static frame may be lifted from the floor and moved about as desired.

In many instances it is desirable to use rigid support pendulu-ms. In order that the movable framework have vertical freedom bottom loop 211 of such pendulums has a greater vertical extent than necessary to encompass the nylon bushing upon which each is journalled. The lower pivot moves within the loop so that the framework may lift the static frame Without bending or otherwise distorting a rigid support pendulum. Obviously this provision is not necessary when chain or otherwise articulated pendulums are used.

Box shields 1.76, 177 move with the framework when the crib is lifted. Their relative position with respect to the vertical posts of the static frame does not change appreciably. There is a relative vertical displacement equal to the vertical gap between transverse members 142 and the top surface of the side rails. The guide rollers 163 preclude any transverse displacement of the box shields with respect to the vertical posts both at the time the crib is lifted and during its normal operation. The shields also cooperate with the guide rollers to inhibit side sway of the movable framework while it is operating longitudinally.

Referring now to FIG. 8, a slight clearance exists between the periphery of a given guide roller andthe inner faces of the'side walls 1'73, 179" of the respective box shield. in normal operation the side walls are not in contact with the rollers and no friction drag is imposed by the rollers on the motion of the movable framework. However, any tendency toward side sway in either trans.- verse direction moves a side wall of the box shield against the periphery of a roller.. The rollers are mounted to turn freely so that no appreciable friction drag is created despite the contact between side wall and roller. In this fashion the guide rollers 163 atop the vertical posts inhibit side sway of the framework and the mattress.

The rollers 163 of necessity operate at the top level of the movable framework. It is desirable to achieve a similar effect near the bottom of the framework. For that reason a plurality of lower guide rollers such as roller 215 are fixed to members 139 of the static frame so that the roller periphery extends outwardly beyond the side member in position to contact the movable framework near the top of the side rail thereof. Preferably the lower guide rollers are located each near a corner of the static frame so that the maximum space exists between the rollers. They are mounted similarly to upper rollers 163 so that normal oscillation of the movable framework creates no friction drag by contact between the framework side rails and the lower guide rollers.

The optimum arc of oscillation has a cord length of from to inches as stated heretofore. Different bed occupants, of course, will be mollified at difierent points of this optimum span. Therefore, means may be provided for adjusting the lengths of the pendulums. One such means is the previously described adjustable pivot point of FIG. 1. Another such means is illustrated in FIG. 12. In that figure a vertical post i l-7B similar in most respects to the vertical posts of the embodiment of FIG. 6 has a pivot block 149B fixed within the channel of the post near its upper end. The block accommodates a journal bolt 1628 which may mount a roller (not shown) similar to roller 163 of FIG. 8.

A support pendulum ESQB is supported from a pivot bolt 1523. However, since in the embodiment of FIG. 12 it is not necessary for the pendulum to be journalled with respect to this bolt, the bolt may be threadably engaged with the pivot block to anchor pendulum support 159B with respect thereto. The support pendulum is lodged about the bolt and clamped between a pair of washers 217.

A vertical groove 219 extends downwardly in the back of the vertical post from a point just below the pivot block. An L shaped pivot arm 221 has a horizontally extending lug 2.22 shaped to slide in the groove. The pivot arm extends from within the channel of the vertical post outwardly beyond the support pendulum. A port 223 extends vertically through the pivot arm and the pendulum support passes through it. The port is sized so that the arm slides along the support pendulum with substantially no horizontal play of the pendulum within the port. 1

A clamp bolt 225 extends through the pivot arm lug. The bolt clamps a washer 226 against the back of the vertical post. A control cable 227 is clamped between the washer and a head 228 of the clamp bolt. Thus the bolt, the washer and the pivot arm form an assembly movable along the extent of groove 219. Control cable 227 extends from a flexible conduit 231 fastened at its upper end to the vertical post adjacent the groove. The

-control cable and the conduit extend to a speed control mechanism 232 of a vari-speed motor which may be the motor 192 of FIG. 7. Thus vertical adjustment of a pivot arm 221 can change the speed of the motor.

A pivot arm similar to arm 221 may be moved vertically to change the efiective pendulum length of each pendulum support 1598. Such length change of course affects the arc of the pendulum and its period. The cable 227 may be clamped to a single pivot arm and so linked to the vari-speed control that the cycle of the motor is changed commensurate with the adjusted period of the pendulum. Graduations may be affixed adjacent the groove on the vertical post to afiord means for setting all pendulum lengths with accuracy.

The operation of the oscillating bed of the invention is considerably improved over conventional devices by the oppositely extending extension springs used to communicate the motive power from the motor to the bed or crib. in addition to augmenting the eccentric arm action in reversing the swing of the movable framework at a time when the horizontal force of the eccentric arm motion is least, the springs also absorb much of the backlash shock conventionally imposed upon the motive source in stopping the device or at the moment of reversal. The backlash effect can be further diminished by a friction brake 235 which may be mounted with respect to the drive wheel 1% in the manner shown in FIGS. 6, 7 and 10. In those figures upstanding angle 236 fixed to beam 191 by conventional means supports a resilient horizontal band 237 which extends from the upstanding angle to adjacent the periphery ofdrive wheel 196. A friction pad 238 fixed to the resilient band bears against the disk periphery. The resilient band is loaded against the drive wheel so that it 10 does not substantially interfere with normal rotation of the wheel. The hand does impose suificient drag to in hibit reverse rotation of the wheel due to framework backlash which would otherwise impinge upon the motor.

The brake not only adds to the longevity of motor operation but prevents much of the noise which conventional oscillating beds create at the end of each oscillation arc.

FIG. 11 illustrates an alternate means for mounting the ends of the extension springs to drive Wheel 1% or to an eccentric arm. A pivot pin 241 threaded at end 242 journals a mounting bushing 243. The threaded end may fit into a tapped hole in the wheel or may extend through and be secured in place by a pair of lock nuts (not shown). Two peripheral grooves 24d, 245 extend around the mounting bushing. An end of each extension spring is looped about the bushing so that it rides in a groove. The bushing is rotatable on the pin so that the springs may maintain their relative position despite rotation of the drive wheel.

Since the extension springs are preloaded to a very low poundage, there is a tendency for the mattress on the movable framework to oscillate in response to very small imposed loads. Such motion is inconvenient when a crib occupant is being tended. Therefore, the invention provides a friction brake 251 conveniently protruding from the side rail of the movable framework. Brake 251 extends inwardly through the side rail and has a friction pad 252 fixed to its inner face. A similar static pad 253 is fixed to the adjacent portion of the static frame. Knee pressure against the friction brake brings the two pads into contact and effectively prevents oscillation of the mattress bearing the crib occupant. A slidable friction lock may be used for more permanent restraint. The lock is shaped to slide across the exposed face of the brake and hold the two friction pads in contact.

Extension springs have been utilized in all of the previously described embodiments of the invention for the linkage between the motive means and the: crib or bed. However, it is possible to utilize compression springs to transmit power resiliently and to equalize the power transmitted despite the phase of the eccentric arm or the drive wheel turned by the motive means.

FIG. 13 illustrates an alternate embodiment of the invention similar in most respects to the embodiments of H63. 4 and 5. However, the embodiment of FIG. 13 uses compression springs. Like parts of FIG. 13 have been given like reference characters to FIG. 4. Beam 92 has a notch 2C near upright 89 of static frame 85. Motive means such as an electric motor 254 is mounted on a vibration absorbent pad 254A within the notch. The motor turns an eccentric arm 2.55. "if he outer end of the eccentric arm mounts a thrust plate 256. The thrust plate is pivotable along a horizontal axis with respect to the eccentric arm. A power arm 257 is slidably attached by means of the thrust plate'to the eccentric arm. An end 257A of the power arm is pivotally mounted to end member 164 of the movable framework by a bracket 258. A pair of compression springs 25d,

260 are mounted one on either side of the thrust plate about the power arm. A thrust collar 2-61 is mounted to the rod so that the end of spring 259 bears against the collar. A thrust collar 262 is similarly mounted with respect to spring see.

Motor 25 is oriented transversely with respect to upright 89 so that the power arm may extend longitudinally between the upright and a wide hinge pendulum 99 depending from crossarm $5 of the static frame. As in the previously described embodiment of FIG. 4, the lower end of each pendulum 99 is pivotally fixed to a side rail of the framework by a stub rod 3.61.

In operation, eccentric arm 255 is turned by motor 2% and pushes thrust plate 256 against spring 25? or 269, depending upon the position of the eccentric arm with respect to end member 164. Since the power arm is slidably connected to the eccentric arm, the latters moscenes? tion is not directly transmitted to the power arm. in FIG. 13 the motor is turning clockwise and the eccentric arm is still exerting a rightward thrust against spring 26%, compressing it between the thrust plate and collar This tends to move the power arm, and hence end memher 1% and the movable framework, to the right in that illustration. A similar but opposite motion is imposed upon the framework when eccentric arm 255 rotates until the thrust plate begins to compress spring 259.

The compression springs give much the same advantages as'do the extension springs of the previously described embodiments. They tend to even out the trans-- mittal of motive power to the framework and insulate the motor against backlash shock. However, the design requirements for compression springs to accomplish these purposes makes the compression springs much more expensive than comparable extension springs. Hence the latter are preferable.

The vibration absorbent pad clamps motor noise considerably. In combination with the smooth power transmission alforded by the abovementioned sprin s the pads result'in an oscillating bed having an operating noise level substantially below that of any comparable device.

Apparatus has been described with respect to PEG. 12 which is capable of varying the speed of the power source for oscillating the crib with respect to a chan e in pendulum length. The same linkage described therein as controllin the speed of a single motor can be used to actuate a suitable selector which will couple the eccentric arm which transmits the oscillatory motion to the movable framework to any one of two or more constant speed motors of different speeds. Simple clutch mechanisms capable of performing this task are available at a lesser cost than a suitable vari-speed motor.

Several embodiments of the invention have been illustrated and described in the foregoing specification. However, many more embodiments within the scope of the invention will be apparent to those skilled in this particular art. The true scope of the invention is, therefore, defined by the accompanying claims rather than by the foregoing specification.

We claim:

1. A bed for oscillating an occupant and a mattress comprising a static frame including a plurality of vertical posts extending u wardly therefrom, a support pendulum pivotally mounted on each vertical post to depend downwardly therefrom, each support pendulum being mounted on the vertical post adjacent to the uppermost extent of the post, an oscillating framework surrounding the static frame, a mattress holder secured in the framework at a level. below that at which the support pendulums are mounted to the vertical posts, means for pivotally joining the lower end of each support pendulum to the framework, each support pendulum being joined to the framework at a position below the mattress holder and adjacent to the lowermost extent of the static frame, means extending from the static frame to bear against the movable framework and inhibit side sway thereof, an electric motor having a rotating drive shaft and fixed to the static frame below the mattress holder, said electric motor rotatively driving said rotating drive shaft at a rotational speed in number of revolutions per unit time which is approximately equal to the natural frequency of the support pendulums per said unit time, a pair of extension springs, and means for connecting an end of each of the springs to the drive shaft of the electric motor at a point spaced from the axis of rotation of the drive shaft, the opposite end of each extension spring being fixed to the movable framework at horizontally opposed points with respect to the center of rotation of the drive shaft so that the springs resiliently communicate the motion of the drive shaft to the movable framework to oscillate the framework with respect to the static frame substantially in accordance with the natural period of the support pendulums, each extension spring being fixed it can to the movable framework at a point adjacent to said joining of the lower end of each support pendulum to the framework at approximately the center of percussion of the support pendulurns.

2. Apparatus in accordance with claim 1 in which the means for connecting the springs to the shaft comprises a drive wheel fixed to the drive shaft of the motor, a pivotable pin extending from a point adjacent tie periphery of the drive wheel, and means on the pivotable pin for holding the ends of each extension spring.

3. A bed for oscillating an occupant and a mattress comprising a rectangular static frame having a vertical post adjacent each corner of the static frame, a pendulum pivot extending horizontally outboard from eachvertical post, a support pendulum mounted on each pivot and depending downwardly therefrom at each corner of the static frame, a pair of spaced end members, a pair of spaced side rails extending from end member to end member and rigidly joined thereto so that the end members and side rails form a movable framework, a mattress holder secured in the framework at a point below the pendulum pivots, means pivotally joining each support pendulum at its bottom end to a side rail near the juncture of the side rail with the end member, a hollow vertical box extending inwardly parallel to the side rails from each edge of each end member and forming a shield for the vertical post and the support pendulum mounted thereto, a guide roller pivotally mounted to the top of each vertical post so as to rotate in a horizontal plane, each guide roller being adapted to contact the opposite sides of the respective hollow box shielding the vertical post, an electric motor having a rotating drive shaft and fixed with respect to the static frame below the mattress holder, 2:. drive wheel fixed to the rotating drive shaft of the motor, a mounting pin rotatably fixed to the drive wheel remote from the center of rotation thereof, and a pair of extension springs one extending horizontally from the mounting pin in each direction parallel to the side rails of the movable framework, the end of each spring remote from the drive wheel being fixed to an end member of the movable framework so that the springs resiliently communicate the motion of the drive wheel to the movable framework, and means sensitive to audible stimulation for initiating the drive cycle of the electric motor.

4. A bed for oscillating an occupant and a bed mattress comprising a static frame, a plurality of support pendulums depending from the static frame, a movable framework adapted to carry a mattress and supported by the support pendulums, a motor on the bed, and a pair of extension springs each fixed at one of its ends to the framework and having their opposite respective ends mounted eccentrically to the drive shaft of the motor for moving the framework with respect to the static frame, said drive shaft of the motor rotating a number of revolutions per unit time'which is approximately equal to the natural frequency of the support pendulums per said unit time, the ends of said pair of extension springs which are fixed to the framework being so fixed at a position adjacent to the point at which the framework is supported by the support pendulums and adjacent to the center of percussion of the support pendulums.

5. A bed for oscillating an occupant and a mattress comprising a rectangular static frame having a vertical post adjacent each corner of the static frame, a pendulum pivot extending horizontally outboard from each vertical post, a support pendulum mounted on each pivot and depending downwardly therefrom at each corner of the static frame, a pair of spaced end members, a pair of spaced side rails extending from end member to end member and rigidly joined thereto so that the end members and side rails form a movable framework, a mattress holder secured in the framework at a point below the pendulum pivots, means pivotally joining each support pendulum at its bottom end to a side rail near the juncture of the side rail with the end member, a hollow vertical box extending inwardly parallel to the side rails from each edge of each end member and forming a shield for the vertical post and the support pendulum mounted thereto, a guide roller pivotally mounted to the top of each vertical post so as to rotate in a horizontal plane, each guide roller being adapted to contact the opposite sides of the respective hollow box shielding the vertical post, an electric motor having a rotating drive shaft and fixed with respect to the static frame below the mattress holder, a drive wheel fixed to the rotating drive shaft of the motor, a mounting pin rotatably fixed to the drive wheel remote from the center of rotation thereof, and a pair of extension springs one extending horizontally from the mounting pin in each direction parallel to the side rails of the movable framework, the end of each spring remote from the drive wheel being fixed to an end member of the movable framework so that the springs resiliently communicate the motion of the drive wheel to the movable framework, and said motor rotatively driving said rotating drive shaft at a rotational speed in number of revolutions per unit time substantially equal to the natural frequency of said support pendulums per said unit time.

6. A bed for oscillating an occupant and a mattress comprising a rectangular static frame having a vertical post adjacent each corner of the static frame, a pendulum pivot extending horizontally outboard from each vertical post, a support pendulum mounted on each pivot and depending downwardly therefrom at each corner of the static frame, a pair of spaced end members, a pair of spaced side rails extending from end member to end member and rigidly joined thereto so that the end members and side rails form a movable framework, a mattress holder secured in the framework at a point below the pendulum pivots, means pivotally joining each support pendulum at its bottom end to a side rail near the juncture of the side rail with the end member, a hollow vertical box extending inwardly parallel to the side rails from each edge of each end member and forming a shield for the vertical post and the support pendulum mounted thereto, a guide roller pivotalliy mounted to the top of each vertical post so as to rotate in a horizontal plane, each guide roller being adapted to contact the opposite sides of the respective hollow box shielding the vertical post, an electric motor having a rotating drive shaft and fixed with respect to the static frame below the mattress holder, a drive wheel fixed to the rotating drive shaft of the motor, a mounting pin rotatably fixed to the drive wheel remote from the center of rotation thereof, and a pair of extension springs one extending horizontally from the mounting pin in each direction parallel to the side rails of the movable framework, the end of each spring remote from the drive wheel being fixed to an end member of the movable framework so that the springs resiliently communicate the motion of the drive wheel to the movable framework.

7. A bed for oscillating an occupant and a mattress comprising a static frame including a plurality of vertical posts extending therefrom, a support pendulum pivotally mounted on each vertical post to depend downwardly therefrom, an oscillating framework surrounding the static frame, a mattress holder secured in the framework at a level below that at which the support pendulums are mounted to the vertical posts, means for pivotally joining the lower end of each support pendulum to the framework, means for extending from the static frame to bear against the movable framework and inhibit side sway thereof, an electric motor having a rotating drive shaft and fixed to the static frame below the mattress holder, said electric motor rotatively driving said rotating drive shaft at a rotational speed in number of revolutions per unit time which is approximately equal to the natural frequency of the support pendulums per said unit time, a

pair of extension springs, means for connecting an end of each of the springs to the drive shaft of the electric motor at a point spaced from the axis of rotation of the drive shaft, the opposite end of each extension spring being fixed to the movable framework at horizontally opposed points with respect to the center of rotation of the drive shaft so that the springs resiliently communicate the motion of the drive shaft to the movable framework to oscillate the framework with respect to the static frame substantially in accordance with the natural period of the support pendulums, said means for connecting an end of each of the springs to the drive shaft of the electric motor comprising a drive wheel fixed to the drive shaft of the motor, a pivotal pin extending from a point adjacent the periphery of the drive wheel, and attaching means on the pivotal pin for holding the end of each extension spring on the pivotal pin, and a friction brake constantly loaded against the drive wheel to inhibit backlash resulting from inertial forces of the oscillating framework imposed upon the motor through the extension springs.

8. A bed for oscillating a mattress and an occupant upon the mattress comprising a static frame having a base and a plurality of vertical posts extending upwardly from the base, a support pendulum mounted on. each vertical post adjacent the upper end thereof and depending downwardly therefrom, an oscillating framework surrounding the static frame, a mattress holder secured in the frame work at a level below that at which the support pendulums are mounted on the vertical posts, means for connecting the lower end of each support pendulum to the framework at a location below the mattress holder and adjacent to the base of the static frame, an electric motor having a rotating drive shaft, said electric motor being fixed to the static frame below the mattress holder, said electric motor rotatively driving said rotating drive shaft at a rotational speed in number of revolutions per unit time which is approximately equal to the natural frequency of the support pendulums per said unit time, a pair of extension springs, means for connecting an end of each of the springs to the drive shaft of the electric motor at a point spaced from the axis of rotation of the drive shaft, and means for connecting the opposite end of each extension spring to the movable framework at horizontally opposed points with respect to the center of rotation of the drive shaft which are adjacent to the means for connecting the lower ends of the support pendulums to the framework so that the springs resiliently communicate the motion of the drive shaft to the movable framework at approximately the center of percussion of the support pendulums to oscillate the framework with respect to the static frame at approximately the natural period of the support pendulums.

9. A bed for oscillating an occupant and a bed mattress comprising a static frame, a movable frame supporting the mattress, a plurality of pendulums connected between the static frame and the movable frame and supporting the movable frame for oscillatory motion relative to the static frame, means connected between the movable frame and the static frame for imparting oscillatory motion to the movable frame and including a variable speed motor and an eccentric arm rotated by the motor, said oscillatory motion imparting means further including link means conmeeting between the eccentric arm and the movable frame, the connection of the link means to the movable frame being at a position adjacent to the point at which the movable frame is supported by the pendulums and adjacent to the center of percussion of the pendulums.

10. A bed according to claim 9 including means for changing the effective length of all the pendulums to effect a change in the natural oscillatory period of the pendulums, and means opcratively connected between the variable speed motor and the means for changing the effective length of the pendulums to vary automatically the speed of the motor in response to operation of the means 1 5 for changing the effective length of the pendulums whereby the link means imparts oscillatory motion to the movable frame in accord with the natural period of the pendulurns as determined by the means for changing the effective lengths of the pendulums.

References Cited in the-file of this patent UNITED STATES PATENTS 459,708 Lund etal Sept. 15, 1891 Becker Mar. 6, 1923 Crane Sept. 16, 1929 Fleaca Aug. -1, 1933 Wilke Dec. 18, 1934 Yurkovich Aug. 9, 1949 Chodacki et a1. fan. 3, 1950 Chodacki et a1 Maj 6, 1951 Carrier et a1 Mar. 29, 1955