US2481477A - Screw and nut bed actuator - Google Patents

Description

Sept. 6, 1949. w, PEERY 2,481,477

SCREW AND NUT BED ACTUATOR Filed June 11, 1946 6 Sheets-Sheet 1 x k s 5 w H R "Q 3 l k,

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INVENTOR- #1442779? 5 Fi z/Pr ATTORNEY Sept. 6, 1949. w, PEERY 2,481,477

SCREW AND NUT BED ACTUATOR i...'nllli T W44 75/? A. BY

Sept. 1949- w. E. PEERY 2,481,477

SCREW AND NUT BED ACTUATOR Filed June 11, 1946 6 Sheets-Sheet 3 HTTO/P/VZYS Sept. 6, 1949. w. E. PEERY scnnw AND mm am) ACTUATOR 6 Sheets-Sheet 4 Filed June 11, 1946 IN VEN TOR. WA: 747? A Pawy ArraPn zys' Filed June 11, 1946 Sept. 6, 1949. w. E. PEERY 2,481,417

SCREW AND NUT BED ACTUATOR 6 Sheets-Sheet 5 I INVENTOR. 14 4474? .5. PZ/P Sept. 6, 1949. w. E. PEERY scREw AND mm BED ACTUATOR 6 Sheets-Sheet 6 Filed June 11, 1946 mmvroa. WAL 75R .4? PIA-P) Patented Sept. 6, 1949 UNITED STATES PATENT OFFICE SCREW AND NUT BED ACTUATOR Walter E. Peery, Morristown, N. J.

Application June 11, 1946, Serial No. 675,989

This invention relates to mechanisms whereby rotary motion may be translated into linear or longitudinal movement for operating movable parts such as the head portion and knee portion of a hospital bed to change the inclination of either in accordance with the wishes of the patient.

A principal object of the invention is to provide mechanisms of this character that have suitable form so that they may be attached conveniently to almost every type of hospital bed now in use without extensive alteration of the bed construction.

Another object of the invention is to provide mechanisms of this character which will give either the patient or the nurse either manual or power-operated control over the movable parts of his bed and which are inexpensive and simple to manufacture and to install.

A further object of the invention is to provide mechanisms that may be operated either manually by means of a hand-operated crank or by means of a motive power derived, for example, from an electric motor.

A further object in connection with electrical motor drive actuating construction is to provide electrical circuits utilizing limit switches whereby operation of the motor in each direction for raising and lowering the moving parts of the bed will be limited to the practical limiting positions of the movable parts and whereby movement beyond a limiting position will be prevented, while movement in the opposite direction toward original position may continue to be effected under the control of the patient or the nurse.

Still another object of primary importance is the provision of coupling between the mechanical and electrical controls of such a nature that either may be operated independently or simultaneously without interfering with the adjustment of the mechanism.

Yet another object of the invention is to provide mechanisms of this character which may be utilized for other purposes besides that of the operation of hospital beds, for example, as means for actuating computing machines wherein two quantities or a series of quantities are to be added together, or for various other applications.

Yet another object of the invention is to provide mechanisms which are adapted for use where a controlled rate of movement of one part requires an initial manual setting or positioning.

Yet another object of the invention is to provide mechanisms of this character for adaptation to applications requiring two controlled lo cations in which the controls are mutually independent, such mechanisms to be arranged to allow transfer of control or simultaneous control from two remotely separated places, for example, in connection with the steering of ships where two locations of control are used.

. To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the novel method, and in the novel construction and arrangement of parts hereinafter described in detail and then sought to be defined in the appended claims, reference being had to the accompanying drawing which forms a part hereof, and which shows merely for the purposes of illustrative disclosure, preferred embodiments of the invention, it being expressly understood, however, that various changes may be made in practice within the scope of the claims without digressing from the inventive idea.

In the drawing, wherein similar reference characters denote corresponding parts:

Figure 1 is a longitudinal section of one form of actuating mechanism embodying the invention;

Fig. 2 is a transverse section taken along line 2-2 of Fig. l;

Fig. 3 is a perspective view of a hospital bed frame showing application thereto of mechanisms like that of Figs. 1 and 2 for operating the head and knee rests of the bed;

Fig. 4 is a perspective view of a switch box for operating the mechanisms of Fig. 3;

Fig. 5 is a longitudinal section of a modified mechanism;

Fig. 6 illustrates in elevation the application of the mechanism of Fig. 5 to a hospital bed for operating the head rest;

Fig. 7 is a diagrammatic view of electric control circuits for either modification;

Fig. 8 is a partial longitudinal section showing a modified application of the actuating mechanism for another purpose;

Fig. 9 is a partially diagrammatic illustration of a further application; and

Fig. 10 is a partially diagrammatic illustration of yet another application of the actuating mechanism for dual or multiDle control.

Referring to the drawings, and first to Figs. 1 and 2. the lead screw I0 is supported by the thrust bearings 12 and l2a, the nut Hi, the casting l4. and the thrust tube l5 assembly. The tube I5 and casting H are firmly and inflexibly joined to one another at H; by welding, riveting, threading or some other suitable means. The

3 nut I3 is free to rotate in the casting l4. This nut carries a ring gear H, which meshes with pinion l8, fixed on the stub shaft IS. The shaft I9 is carried rotatably by a pinion 28 which is rotatively borne on the nut I3 and which meshes with the drive pinion 2| keyed to the drive shaft 22 of the motor 23. The motor is flxed suitably at 24 to the casting l4. The shaft I3 is keyed to pinion 25 which meshes with a fixed gear 26 fixed at 26a and carried "by the casting l4. This gear 26 meshes with a pinion 21 keyed or otherwise fixed at 21a. to the stub shaft 28 which is rotatively borne in a bearing 38 provided on the gear 20. A second gear or pinion 3| is keyed or otherwise fixed at 3|a. to the stub shaft 28 and meshes with the pinion l1. Thus, because pinion 26 is fixed, rotation of the drive gear 2| causes rotation of the free gear 28 and moves the pinions 25 and 21 about a planetary path defined by gear 26, causing them in turn to turn and rotaga the respective gears l8 and 3| which both act to drive gear l1, causing it and nut I 3 carried thereby to rotate about the lead screw l6, thereby effecting longitudinal feed of the nut 3 along said screw ID in a direction dependent upon the direction of rotation of motor 23. This longitudinal movement in turn is transmitted through casing I4 to the attached thrust tube i5.

This longitudinal movement of the thrust tube l5 may be utilized for operating movable parts as desired. The mechanism described may, for example, be utilized to operate the head rest 4 depression of their respective plungers 53, 54. Thus rotation of arm 36 in one direction, through link 51, causes rotation in a given direction of switch lever 55 to a limiting point, whereat the latter depresses the plunger of one of the two switches opening the motor circuit at that time and halting operation of the motor so that further motion of the thrust tube IS in the given direction ceases. The circuit through the other limit switch, however, remains closed, so that the motor can be driven in reverse direction and operated until the switch lever 55 has been rotated to a position to open the second switch. The two switches 56, -5I thus serve to limit operation in either direction to defined limits, while permitting operation in reverse direction between the said limits.

The lead screw I8 may be extended rearwardly of the casing l4 as a smooth rod 68 and supported in a bearing 6| pivotally carried at 62 from a portion of the bed frame 4|. A crank 63 has a tubular extension sleeve 64 slidably keyed on the rod 68. This extension sleeve has a rectangular outer surface that is movable of a hospital bed serving to raise or lower the which in turn is hinged at to the bed frame 4|. The thrust tube l5 of the mechanism hereinbefore described is attached at 46 to a link 41. This arm is also attached to link 36.; Thus' movement forwardly of the thrust tube l5,

through the agency of the described coupling,

causes rotation of the interconnected arms 35, 36 and rotation of these arms about their respective pivots 31, 38, so that their respective rollers move on the under face of the head section 44 torotate the latter about its hinge 45 to an inclined position. The extent of inclination is determined by the extent of longitudinal motion in the forward direction imparted to the thrust tube "l5. Movement of the latter in-opposite direction rotates the arms 35, 36 oppositely and permits the head section 44 to rotate in opposite direction about its hinge 45 toward its original position.

Suitable electrical movement limiting means, for example limit switches 50, 5| may serve to limit movement of the thrust tube l5 in either direction by appropriately controlling the switching on and off of electric power to the motor 23 in an electric circuit presently to be described. These switches. 58, 5| are supported suitably from a bracket 52 depending from the motor 23 with their operating plungers 53, 54 facing each other and spaced apart. An operating member or lever 55 is supported pivotally at 56 from the bracket and extends between the plungers 53, 54. A link 51 is pivotally connected at 58 to the lever 55 and at 59 to the arm 36. The switches through a guide slot in a bracket 66 dependent from the frame 4|. Thus, when the crank 63 is in retracted position shown, thesleeve 64 is locked against rotation by guide slot 65 and the crank 63 is likewise locked against rotation. When the crank is pulled outwardly to clear the sleeve 64 from slot 65, the crank 63 may be rotated for manual operation of lead screw l8 and with it the head rest 44 through the movement of thrust tube l5 induced by rotation of lead screw II) which causes the nut l3 to move longitudinally thereon.

A similar actuating mechanism is utilized to operate the knee rest of the bed. The latter comprises the sections 15 hinged at 16 to a section Ti -which in turn is hinged at 18 to a part of the bed frame 4|. Interconnected arms 19, 88 are pivoted respectively at 8|, 82 to fixed supports 83, 84 depending from the frame 4| at opposite sides. The outerendsof arms 18, 88 carry rollers 85, 86 w h cl'r are"movable on the under face of the 1 part 11. The thrust tube l5 of the actuating'fi'nechanism (like that of Fig. 1) is attached to an arm 18 in the same way as thrust tube I5 is connected to arm 38. Thus movement rearwardly of thrust tube l5 induced by rotation of its nut upon its lead screw by action of motor 23 causes rotation of the interconnected arms 19, 88

' about their respective pivots 8|, 82 so that their respective rollers 85, 86 operate on the under face of hinged part 11 to swing the latter about hinge 18 to an inclined position. The extent of inclination is determined by the extent of longitudinal displacement of thrust tube l5. A link 51 connecting the pivoted lever 55' and the arm 41' (Figs. 3 and 7) operates between the plungers 53', 54' of the limit switches 58, 5| (Fig. 7) to limit movement of the hinged part 11 in either direction through control of the motor 23' by the electrical circuit presently to be described. The

' crank 63' attached to rod 68' and extension of the lead screw associated with motor 23' permit manual operation of hinged part 11 in the same way that manual operation of head rest 44 is effected by crank 63.

A modified construction of actuating mechanism is shownin Fig. 5 wherein the planetary gearing of Figs. 1 and 2 is replaced by other drive means. In this figure, the lead screw lllb is supported by the thrust bearing [2b and the nut |3b, casting Nb, and thrust tube I511. The tube |5b and the casting Ilb are firmly and inflexibly Joined to one another by welding, riveting, threading or some other suitable means. The nut I3b is free to rotate in the casting Ilb and carries a ring gear 90 which meshes with pinion gear 9|. Pinion 9I and worm gear 92 are attached to a shaft 93 and supported by bearing Ilb' so that. when the worm gear 92 is rotated by worm gear 94 through the flexible shaft 95 driven by motor 96, the nut I3b will also rotate and provide motion along the axis of the lead screw I 01). The thrust of the nut is taken by the casting Ilb and transmitted to the thrust tubing I5b which is the linking arm between the lead screw I01: and the mechanism to be moved. The flexible shaft connection 95 between the nut assembly and the motor 98 allows the latter to be attached in a fixed position while the nut assembly travels back and forth on the lead screw I0. It can also be seen, however, that the motor 96 could be afllxed to the nut assembly and move back and forth with it instead of being on a fixed mount. The thrust bearing I2b is mounted in pivot l2b' in order to provide for the proper alignment of the whole mechanism during the movement of the linkage to which the motion of this mechanism is imparted. The extension We of the lead screw Ib provides a bearing and mounting for the manual operating crank arm 90 and shaft 99. The shaft extension I0c carries a slot I00 in which a pin IOI, which is firmly afllxed to the shaft 99, is free to slide back and forth. This allows the crank 98 to be pulled out beyond the end of the bed when manual operation is desired or pushed in out of the way when the motor operation is desired, yet maintaining a positive mechanical connection between the crank and the lead screw. The crank shaft 99 also carries a key I 03 which engages a slot I04 in the tubing I 05, which in turn is firmly aillxed to bearing I2b. This key I03 and slot I04 prevent the turning of the crank 90 and therefore the lead screw I 0b when the crank 98 is recessed and motor operation of the mechanism used. It can be seen that many different shaft and crank designs will provide these facilities.

In the drawing, Fig. 6, the actuating mechanism of Fig. 5 is shown attached to the linkage members for raising the head section of a hospital bed and also shows the mechanism for operating limit switches which stop the electric motor when the practical limit of operation has been reached. The arm I 01 pivoted at pivot I09 carries roller I09. The supporting plate H0 is rigidly attached to the bed frame III. As the arm I01 is moved, the head section of the bed H2 is caused to be raised or lowered. The head section H2 is supported by a hinge II3 which allows its movement. The thrust tube I5b attached to the actuating mechanism as previously described transmits the motion from the actuating mechanism or the lead screw I0b to the arm I01. Attached also to the arm IN is a link member Ill which is attached to the limit switch arm II5. Arm I I5 and-the limit switches IIS and I" are attached to a plate II8 which in turn is rigidly attached to the actuating mechanism casting Ilb. As the arm I0! is caused to move between its limits of motion, the movement is transferred to the limit 'switch arm II5 through the link member III.

to the actuating motor 95 is broken and the mechanism may not be operated further in that direction. However, the electric circuit which will enable the actuating motor to operate the mechanism in the opposite direction is not broken.

7 shows in detail the electrical connections for the actuating mechanisms and actuating motors of Figs. 1, 2, 3, or 5 and 6. The electrical components consist of the control box II9 (Fig. 4) which may be placed at the bedside, and which contains two double pole double throw reversing switches I20 and I2I; the head section limit switches 50 or H6 and 5I or III; the foot section limit switches 50' and 5|; the head section actuating motor 29 or 96; the foot section actuating motor 23; and the safety lock-out switch I22.

The control switches I20 and PM are of the type which have a spring return for their operat-- ing blades I20a and I2Ia to the neutral position, thereby requiring a continuous pressure on them from the operator during the interval through which the operation of the actuating motor is desired. This feature prevents the possibility of the bed positions being adjusted beyond the desired position through the inability of the patient to turn the switch off. The limit switches 50 or II6, 5| or III, 50 and 5I' are of the normally closed type and require pressure on their operating plungers 53 or Ga, 54 or Illa, 53' or 54', to open the circuits through them. The motors 23, 96, 23' are conventional series wound motors with connections to the armature and field brought out of the motor enclosure so that they may be connected as required.

The electrical operation is as follows: When the limit switch arms 58 or H5 and 50' are in a middle position so that neither of the limit switches 50 or H5, or 50', or 5I or III or 5| have been opened, the control switch I20 may be placed in either the up or down position and operation of the motor will result. For instance, if the switch were thrown so that a and c, b and d are connected (this will be the up" position of the switch I20), current may flow from one side of the power line at a through c to 1', through the field winding F to i, thence through d and b to the up" limit switch 50 or IIIi, through e to h, through the armature winding A of the motor to g, and from there to the other side of the power line. As soon as the mechanism has operated to the place where limit switch 50 or H6 is opened, the motor is automatically stopped and will not proceed further in that direction of rotation. If the control switch is now placed in the down position so that c and e, d and f are now connected, current will flow from one side of the line through a, to the "down limit switch 5| or Ill, thence through the down limit switch 5I or III, then through I and d to 7', through the field winding from 9' to i, then through c and e to h, through the motor armature A to g, and then to the other side of the power line. It will be noticed that, when the control switch blades I20a are in the "down" position, current flows through the field winding in the opposite direction from the fiow that occurs when the control switch is in the up position, while the current through the 7 armature always proceeds in the same direction. that is, from h to g. This reversal of the field current with respect to the armature current is the condition which causes a reversal in the di- .rection of rotation of the motor. Therefore-the broken and stop its operation. It is understood,

of course, that the operation of the mechanism may be stopped at any point between the two limits of operation by releasing the control switch I20. I

The electrical and mechanical operation of th foot section actuating mechanism and electrical components is similar to that of the head section which has just been described. Similar circuits are closed through the primed contacts a, b, c, d, e', f, g, h and field F and armature A of motor 23 when foot switch IZI is operated, and it is not believed necessary to repeat the description.

The lock-out switch I 22 enables a nurse or other authority to open the electrical connections to the actuating motors 23, 96 or 23 to prevent. the patient or others from operating the bed when that is desired.

In addition to the safety features provided by the limit switches,v mechanical stops S, 8 may be placed on the supports .35, 40 and H0. andfa clutch or mechanical disconnect'of conventional type (not. shown) can be incorporated in the actuating mechanism as} 'a--.'further precaution against the mechanism oper' ting beyond practical limits.

The desirable features of the mechanisms of Figs. 1, 2 and 5 which recommend them for practical use are as follows:

1. They may be attached in suitable form to almost every hospital bed in use today. This maybe done without extensive alternation of the bed construction.

2. Compared to mechanisms for beds which have been been recently invented for the purpose of giving the patient more control over his bed. the instant ones are relatively simple and inexpensive to manufacture and install. This is particularly important in view of the financial condition and economics of operation existing in most hospitals today. Funds are lacking for expensive beds, yet the cost of nursing has risen to the point where some means must be employed to reduce the work done by nurses.

3. The controls for a bed equipped with these actuating mechanisms are simple and will be easily understood and operated .by the patient. There are only two switchesone to control the foot section, the other to control the head section. Each switch may be depressed or raised to obtain downward or upward movement. The switches come to rest automatically in a neutral position which prevents the mechanism-in usefrom being turned on and operated beyond the desired amount through the inability of thelpatient to turn the switch oif. Equipment is provided which prevents the motion of the bed from going beyond practical limits. The electric circult allowsthemechanism in use to be locked out when operation sired.

4. Of primary importance is the feature which retains manual operation of the bed with the normal cranks without recourse to adjustments of clutches or other mechanisms so that the bed may still be operated manually in the event of failure of the electric power or of the actuating mechanism. A feature of the mechanism is that both electric and manual operation may'proceed independently or coincidentally with regard to the'other without interfering with the adjustment of the mechanism.

The mechanisms of. Figs. 1, 2 and 5 have other applications besides hospital beds wherein an interchange between manual and electric operation is desirable for producing a motion along the axis of a screw without interference between the methods of producing the motion. A broader application, for example, would be where two cranks or two motors might be used to produce the motion with this device; or, perhaps, any two sources of rotational power. One source would be applied where the crank 63" and the other source, a motor 23", are shown in Fig. 8. The casting l4" contains all the elements of casting H of Fig. 1 and operates thrust tube IS" in the same way. This device would then provide a means of integrating .or algebraically adding or subtracting the rotation of the two rotational sources It can be seen that, if the two sources were rotated so that the effect of both was to .propelthe nut in the same direction, the movement of the nut would be a function of the summation of the rotations of the two rotational sources. extent that'the nut would slow down in its axial motion or stop or reverse, depending on the rela- -tive' speeds of the two rotational sources. Thus a subtraction would be effected. Used in this way, the mechanism could be applied to computing machines where twoquantities or a series of quantities were to be added or subtracted. The resultant motion of thrust tube I5" could be coupled to a recorder Rfor such purpose.

The actuating mechanisms could be applied to machines where a controlled rate of movement of one part requires setting or positioning manually. A motor connected at either of the two .power input connections could provide the controlled movement and a hand crank at the other connection could provide the manual adjustment. Fig. 9 is illustrative. The position of the thrust tube l5' can be adjusted to an initial position 'by' means of the crank 63" 'andthen the motor may be turned on to give a motor-operated movement tothe thrust tube I5'. 'Or while the thrust tube IV" is being moved under power by the motor 23', the hand crank-63" may be used to accelerate or decelerate the movement for purposes of positioning or adjustment of rate of movement. 7

The mechanisms are adaptable to applicatio requiring two control locations in'which the controls are mutually independent. Such an application is shown in Fig. 10. Therein the mechanism could be operated by two remotely-controlled motors, the control locations of'which could be far apart. transfer of control or simultaneous control from two different places. An application of this might be in connection with the steering of ships where two locations of control are used. For example, in Fig. 10, the motor 23" is operated by the reversing switch on the ship's bridge in by the patient is not de.-

One source could be reversed to the The mechanism would allow its electric circuit while a motor I36 coupled to lead screw I" is operated by a reversing switch I31 in its independent electric circuit at the stern of the ship. The thrust tube Iii is coupled to lever I38 by a link I39. Lever I38 operates the rudder I49. Actuation of either motor 23" or I36 causes movement of thrust tube I and consequently of rudder I40. Both motors, if operated simultaneously, are additive in their effect upon the rudder motion,

Other uses and applications of the mechanisms are possible.

While specific embodiments have been disclosed, it is to be understood that variations in structural detail are possible and are contemplated. There is no intention, therefore, of limitation to the exact details shown and described.

What is claimed is:

Actuating mechanism for translating rotary motion into linear motion comprising a lead screw, a casing, a nut within said casing and rotatable about and movable longitudinally of said lead screw, 9. motor, gear means coupling said motor to said nut, means for rotating said lead screw thrust means secured to said casing and movable therewith longitudinally of said lead screw in response to longitudinal motion of said nut along said lead screw resulting from its rotation on said lead screw or from rotation of said lead screw, a bed, a. pivoted movable part on said bed, and means coupling said movable part to said movable means.

WALTER E. PEERY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 937,544 Post Oct. 19, 1909 1,477,599 Sears Dec. 18, 923 1,793,228 Hackethol Feb. 17, 1931 1,941,263 McIntosh Dec. 26, 1933 2,086,030 Hodgson July 6, 1937 2,14 ,050 Smith Dec. 20, 1938 2,283,476 Waibel May 19, 1942 2,311,972 Simpson Feb. 23, 1943 2,318,814 Strong May 11, 1943 2,333,34 Scrivener Nov. 2, 1943 2,349,701 Buttikofer May 23, 1944 2,375,172 Arter May 1 1945 2,387,713 Bradford Oct. 30, 1945 2,403,092 Lear July 2, 1946 2,424,492 Morris July 22, 1947 FOREIGN PATENTS Number Country Date 699,426 Germany Nov, 28, 1940

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