US3548822A

US3548822A - Device to prevent hyperventilation

Info

Publication number: US3548822A
Application number: US669973A
Authority: US
Inventors: Henry W Seeler
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-11-07
Filing date: 1967-09-22
Publication date: 1970-12-22
Anticipated expiration: 1987-12-22
Also published as: CH419461A; NL301476A

Description

United States Patent [72] Inventors Henry W. Seeler 3,242,921 3/1966 Seeler 128/ 145.5

Dayton, Ohio; Pn-ma ry Examiner-Richard C. Pinkham g:; :2:;; Athenon Road Assistant Examiner-Richard W. Diaz pp No. 669,973 Attorney Dybvig and Dybvig [22] Filed Sept. 22, 1967 32;": i g' f 6 ABSTRACT: A device to prevent hyperventilation during 45 P t t d rapidly repeated inhalation and exhalation comprises a bul- I 1 a en 6 bous member having an inlet port adapted to communicate with the user's airway, an outlet port and a third port adapted 54] DEVICE o PREVENT HYPERVENTILATION to communicate with the ambient atmosphere. When the user 7 Chin, 8 Drawing at inhales through the inlet port of the bulbous member, a first n pressure responsive valve closes the outlet port and a second [52] 128/1453 pressure responsive valve opens the third port to permit the 128/1455 user to inhale fresh air. When the user exhales into the inlet FFC A v port, said one first valve opens and said second valve closes to [501 Field ofSearch 128/ 145.2, permit the user to exhale through the bulbous member to said 145-8 outlet port. A storage tube disposed within the bulbous member and communicating with said inlet port retains a por- [56] Rae-mm cued tion of the users exhaled air for return to the users lungs upon UNITED STATES PATENTS subsequent inhalation by the user from said first port. A cap is 2,428,451 10/ 1947 Emerson 128/1457 provided for closing the inlet port, and the bulbous member is 3,099,985 8/1963 Wilson 128/ 145.5 resiliently compressible to allow for squeezing the bulbous 3,216,4l3 l 1/1965 Arecheta 128/ 145.7 member to force air through the outlet port.

1 18 I v I0 I 22 I I r I I PATENTED 0513221970 SHEE] 2 OF 2 JHI DEVICE TO PREVENT I-IYPERVENTILATION This is a division of application Ser. No. 236,029 filed Nov. 7, 1962, now US. Pat. No. 3,356,100.

This invention relates to a device for use in lung powered breathing assistance applications and more particularly to a device for preventing hyperventilation in lung powered breathing assistance operations. However, the invention is not necessarily so limited.

An object of the present invention is to provide a new and improved breathing assistor or resuscitator apparatus.

A further object of the present invention is to provide a new and improved bellows device which can be manually manipulated to pump a fluid and which, withminor adjustment, can be used as an adapter to protect a human operator against hyperventilation in lung powered blowing operations.

A further object of the present invention is to provide a breathing assistor or resuscitator device suitable for manual operation and, with minor adjustment, suitable for operation as a mouth-to-mask resuscitator.

Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.

In the drawings, FIG. 1 is a sectional view of a breathing assistance device constructed in accordance with the present invention.

FIG. 2 is a sectional view, taken substantially along the line 2-2 of FIG. 1.

FIG. 3 is a fragmentary, sectional view illustrating a bellows unit used in the device of FIG. 1 prior to assembly of a fluid distribution valve therein.

' FIG. 4 is a fragmentary, sectional view, taken substantially along the line 4-4 of FIG. 3.

FIG. 5 is an elevational view of the fluid distribution valve with portions broken away to reveal the interior construction thereof, this figure illustrating one condition of operation of the fluid distribution valve.

FIG. 6 is an elevational view of the fluid distribution valve with portions broken away to illustrate another condition of operation thereof.

FIG. 7 is a fragmentary, elevational view illustrating one mode of operation of the breathing assistance device of FIG. 1.

FIG. 8 is a fragmentary, elevational view illustrating a second mode of operation of the breathing assistance device of FIG. 1. 7,

Referring to the drawings in greater detail, the resuscitation device disclosed includes two basic components. One basic component is a dual purpose bellows unit 10 which can be used alternatively to pump air into the lungs of a patient or other chamber, or as an adapter for mouth-to-mask resuscitation or for a similar blowing operation, the bellows unit being so constructed as to avoid hyperventilation in the user thereof. The other basic component is a fluid distribution valve which enables a fluid, such as a breathing gas, to be forced into a patients lungs or other chamber and also enables the fluid or breathing gas to be expelled from the patients lungs or other chamber to the ambient atmosphere.

The bellows unit, which is best illustrated in FIGS. 1 through 4, comprises a generally hollow ovate bag or bulb constructed of a resilient material, which may be a rubber or a synthetic plastic material. At the lower end of the bellows unit, as viewed in FIG. 1, a thickened wall 12 surrounds an enlarged opening to the interior of the bellows unit. As will be more fully described hereinafter, this enlarged opening receives and supports a housing 14 for the fluid distribution valve.

At the upper end of the bellows unit, as viewed in FIG. I, a smaller opening 15 is encircled by an annular wall 16. This annular wall is adapted to receive a plug 18 for closing the opening 15. For securing the plug 18 tightly in the opening 15, the lower end of the plug, as viewed in FIG. 1, has an enlarged annular head'20 thereon, which may be forced into the opening 15 to seat in an annular groove 22 located on the inner surface of the wall 16. The snugness of this fit is insured by means of a ferrule 26 which surrounds the wall 16. A chain 24, as shown, may be used to attach the plug 18 permanently to the ferrule 26.

For reasons which will become apparent in the subsequent description, an annular wall or tube 30 projecting inwardly of the bellows I0 from the opening 15 is integrally secured with the bag 10, so as to extend the opening 15 downwardly toward the lower end of the bag, as viewed in FIG. 1.

The bag III has been previously characterized as generally ovate. However, for operation of the bellows, it is to be understood that the bellows may have any hollow configuration, the important characteristic being that the resilient material with which the bellows I0 is constructed has a natural shape to which it returns after being distorted, as by compression. In the preferred embodiment, it is desired that the bellows It) have the shape of a surface of revolution generated about the central axis of the pipe 30, whereby the outer periphery of the bellows in any plane normal to such axis is essentially circular, as shown in FIG. 2. I-IOwever, those skilled in the art will recognize that any oval or otherwise rotund shape will suffice for the special purposes described herebelow. Also, in the preferred embodiment, the wall thickness of the bellows 10 tapers from diametrically disposed minima 32 to diametrically disposed maxima 34, as shown in FIG. 2, the maxima being approximately twice the thickness of the minima. With such construction, the bellows has two diametrically opposed generally crescent shaped sides joined at 32 by a web of minimum thickness. In consequence of this construction, when the bellows is squeezed by compressing the thin walled sections at 32 together, the thicker walled crescent shaped sides at 34 accumulate a restoring force which will act quickly to restore the shape of the bellows unit upon release of the compressive force.

Finger grooves

36a, 36b, 36c and 36d, together with a thumb groove 36c, formed in the wall of the bellows unit at the thinnest portions thereof, identify the thin wall portions of the bellows unit and assist an attendant in applying a compressive force at the proper points.

Near the lower end of the bellows unit, as viewed in FIG. I, a valve support 38 is shown. This support, which is partially obscured in FIG. 1 by the housing 14, appears in detail in FIGS. 3 and 4. The valve support 38 includes a generally planar wall 39 integral with the bellows 10; but recessed a distance into the interior of the bellows. Located in the wall 39 are a pair of arcuate apertures 40, separated by an intermediate web portion 42. This web portion has a central aperture which receives the stem 46 of an inlet flapper valve 44 adapted to seat upon the interior surface of the wall 39. The flapper valve 44 is anchored by means of a tapered enlargement 48 on the end of the valve stem 46 which, when forced through the aperture in the web 42, expands to firmly lock the valve in place. An opening 47 extends through the exterior wall of the bellows 10 to the apertures 40, so as to permit the passage of air from the surrounding atmosphere into the bellows 10. An annular groove 50, formed in the wall surrounding the opening 47, provides a seat for a' filter element (not shown) which may be used to filter air moving into the bellows through the opening 47, when desired, or for an inlet adapter (not shown), similar in external configuration to the plug 18, but having a conduit therethrough.

In operation, the flapper valve 44 lifts off the wall 39 to permit entry of air from the surrounding atmosphere into the bellows whenever the pressure in the atmosphere exceeds that inside the bellows; but seats on the wall 39 soas to prevent the movement of air or gas from inside the bellows to the ambient atmosphere whenever the pressure in the bellows exceeds that of the ambient atmosphere. The wall 39 is located in the thickened wall portion of the bellows 10, so as, to minimize distortion of the inlet valve support due to compression and relaxation of the bellows.

. As previously mentioned, a fluid distribution valve housing 14 is received in the lower end of the bellows 10, as viewed in FIG, I. This valve housing is formed of two

separable sections

52 and 54, which have circular peripheries adapted to interfit the annular wall 12 located at the lower end of the bellows 10. Adjacent their peripheries, the

housing sections

52 and 54 have

annular grooves

56 and 58, respectively, therein. These annular grooves receive annular tongue portions projecting inwardly from the inner surface of the wall 12 and this tongue and groove construction provides a fluid seal surrounding the housing 14. By means of a slight misfit between these tongue and groove portions, a tension is developed in the wall 12, whereby this wall supports the

housing sections

52 and 54 in intimate engagement.

Leakage of air along the interface between the

housing sections

52 and 54 is retarded by means of a cylindrical boss 64 formed on the face of the housing section 52 which interfits a complementary recess formed in the opposing face of the housing section54. Such boss and complementary recess also center the housing sections, one with respect to the other.

The central portions of the opposing faces of the

housing sections

52 and 54 are recessed away from one another so as to form a fluid receiving cavity 66 therebetween. A fitting 70 formed on the housing section 52 surrounds a first opening 68 leading to the fluid receiving cavity. An aperture 72 formed centrally in the housing section 52 provides a second opening to the fluid receiving cavity. Within the interior of the cavity 66, the aperture 72 is surrounded by an annular valve seat 74, the function of which will be described subsequently.

A fitting 76 formed on the housing section 54 surrounds a third opening 78 leading to the fluid receiving cavity 66. Communication from the opening 78 through the wall of the housing section 54 is afforded by means of apertures 80 flanking a web portion 82, which may be similar in configuration to the apertures 40 and the web portion 42 employed in the inlet valve previously described. As well understood by those skilled in the art, the apertures 80 may also comprise simple holes formed adjacent the web portion 82, only one hole being essential to the function performed thereby. The web 82 has an aperture therein which receives the stem 84 of a resilient flapper valve 86 located in the interior of the fluid receiving cavity 66, As will appear more fully in the subsequent description, this flapper valve 86 functions to distribute a fluid to various openings in the valve housing 14 and, accordingly, is sometimes designated herein as a fluid distribution valve. The stem 84 includes an enlargement 88, which may be forced through the aperture in the web 82 to a point where it can expand to lock the valve 86 in position. An annular wall 89, surrounding the aperture in the web 82 on the interior side of the housing section 54, supports the valve 86 a predetermined distance from the interior wall of the housing section 54.

For purposes of description, it is helpful to subdivide the one piece valve 86 into two sections, one comprising a circular and planar section 90 and the other comprising a diverging peripheral flange portion 92, which surrounds the planar section 90. In the rest position of the valve 86, as shown in FIG. 1, a peripheral surface of the flange section 92 lightly engages the interior wall 94 of the housing section 54 in surrounding relation to the apertures 80, the interior surface of the housing section 54 serving as a valve seat. Also, in its rest position, the surface of the planar portion 90 on the opposite side of the valve 86 lightly engages the valve seat 74 surrounding the aperture 72 and the housing section 52. While it has been described that the valve 86 lightly touches the aforementioned valve seats in its rest position, it will be apparent to those skilled in the art, in view of the mode of operation hereinafter described, that the light touching condition described, while desirable, is not essential and that insubstantial gaps between the valve and its respective valve seats in the rest position can be tolerated.

The operation of the breathing assistor or resuscitator deyice is best understood by reference to FIGS. through 8 of the drawings. FIG. 8 illustrates utilization of the device as a manually operated breathing assistor or resuscitator. For such operation, the plug 18 is inserted into the opening of the bellows unit 10 and a breathing mask 100 is attached to the fitting 70 provided on the valve housing 14 using a suitably shaped, elbow 102. For this purpose, the fitting 70 is provided with a tapered external wall, as shown. The breathing mask 100 can be of a well known conventional construction and for the purposes of the present description, it suffices to note that this breathing mask provides a confined passage from the valve housing 14 directly to the mouth and nose of the patient.

Inhalation by the patient is induced when an attendant manually compresses or squeezes the bellows unit 10, utilizing the conveniently located finger and thumb grooves fonned in the exterior wall of the bellows. When the bellows is squeezed, air within the bellows, which would ordinarily be at atmospheric pressure, is compressed, thereby elevating the pressure of such air above that of the ambient atmosphere. This 7 elevated pressure causes the fluid inlet valve 44 to firmly close. In the event a ball check valve is provided in the plug 18, the elevated pressure will also firmly close this ball check valve. At the same time, the elevated pressure will cause the planar section of the valve 86 to seat firmly on the valve seat 74, thereby preventing any escape of gas from within the bellows to the ambient atmosphere.

As the pressure of the gas within the bellows rises, the annular flange portion 92 of the valve 86 is caused to lift off its valve seat against the interior wall of the housing section 54, permitting the gas within the bellows 10 to escape through the opening 68 in the fitting 70 to the breathing mask and from there to the lungs of the patientgThe approximate configuration of the flapper valve 86 at this time is illustrated in FIG. 5.

As the squeezing action on the bellows l0 continues, progressively more air is forced into the patients lungs, causing the patients lung pressure to rise above that of the ambient atmosphere. When the squeezing action is discontinued and manual pressure on the bellows 10 released, the thickened wall portions of the bellows apply a force, tending to return the bellows to' its initial shape. This action immediately reduces the pressure within the bellows below that of the ambient atmosphere and below that in the patients lungs, whereupon the annular flange portion 92 of the valve 86 seats firmly against the interior wall of the housing section 54 of the housing 14. This prevents movement of any air from the patients lungs into the bellows 10. At the same time, the pressure of the ambient atmosphere applied against the inlet valve 44 located in the wall of the bellows 10 causes this valve to open, permitting air to move from the ambient atmosphere into the bellows 10. Such movement of air into the bellows I0 permits the bellows to return to its natural shape.

As the bellows 10 is returning to its natural shape, the gas pressure in the patients lungs cooperates with the pressure in the ambient atmosphere, both of which exceed the gas pressure within the bellows 10, to lift the planar section 90 of the flapper valve 86 off the valve seat 74 surrounding the aperture 72 in the housing section 52. The configuration of the flapper valve 86 at this time is illustrated in FIG. 6.

The separation of the flapper valve from the valve seat 74 creates a passage through which air may move from the patients lungs, through the breathing mask 100 into the gas receiving cavity 66 of the valve housing 14 and ultimately to the ambient atmosphere through the aperture 72 in such valve housing. Since the gas pressure within the bellows 10 will not rise above that of the ambient atmosphere until further pressure is applied to the bellows, a natural exhalation of air from the patients lungs can continue until such time as the patients lung pressure has dropped to approximately that of the am bient atmosphere. Specifically, patient exhalation can continue until such time as the patients lung pressure is insufficient to hold the flapper valve off the valve seat 74. Since, as previously described, the contact between the flapper valve and the valve seat 74 is a light touching contact in the rest position of the flapper valve, the patients lung pressure at the termination of the natural exhalation described will be only negligibly greater than that of the ambient atmosphere.

From the foregoing description, it will be apparent that repeated manual compression and relaxation of the bellows 10 at properly spaced intervals gauged by the operator, will result in repeated cycles of induced inhalation and natural exhalation of the patient with the flapper valve- 86 operating as a fluid distribution valve in automatically assuming the proper position at each phase of the breathing cycle. 7

FIG. 7 illustrates utilization of the device of FIG. 1 for mouth-to-mask resuscitation. For such purposes, a mask 100 covering the mouth and nose of the patient is attached to the fitting 70 on the housing 14 for the fluid distribution valve.

In operation, the plug 18 is removed from the opening 15 in the upper end of the bellows 10. The attendant administering mouth-to-mask resuscitation holds the mask tightly over the patients mouth and nose while engaging the opening 15 in the bellows unit with his own mouth, as shown in FIG. 7. The attendant then blows or forcibly exhales into the opening 15 of the bellows 10, causing the gas pressure within the bellows to rise above that of the ambient atmosphere. The elevated pressure firmly seats the inlet valve 44 against its seat on the adjacent wall 39, preventing the escape of air from the interior of the bellows directly to the ambient atmosphere. Similarly, and to the same end, the pressure developed in the bellows 10 causes the fluid distribution valve86 to seat tightly on the valve seat 74. At the same. time, the forced exhalation by the attendant causes the fluid distribution valve to lift off its seat against the interior surface of the housing section 54, permitting air to flow from the bellows through the opening 68 in the valve housing 14 to the face mask and from there to the patients lungs. This forced movement of air into the patients lungs causes the patients lung pressure to riseabove that of the ambient atmosphere.

After the attendant has expelled a reasonableamount of air from his own lungs, he commences inhalation without removing his mouth from the opening 15 in the bellows 10. This causes an immediate reduction of gas pressure within the bellows 10 below that of the ambient atmosphere and this reduction of pressure causes the flange portion 92 of the fluid distribution valve to immediately seat against the interior wall of the housing section 52, thereby preventing any flow of air from the patients lungs into the bellows unit 10. The reduction of pressure within the bellows unit 10 also causes the fluid inlet valve 44 to open, permitting the attendant to inhale. As the attendantis inhaling, the patients lung pressure, cooperating with the pressure of the ambient atmosphere, causes the fluid distribution valve to lift off the valve seat 74, permitting the patient to exhale naturally to the ambient atmosphere, as previously described.

During the attendant's inhalation, the first air inhaled comprises his own exhaled air which resides in the interiorly disposed tube 30 within the bellows 10, together with a quantity of his own exhaled air residing in the lower part of the bellows 10 below the end of the tube 30. This air is followed by fresh air from the inlet valve 44 which moves into the patients lungs and replaces the air and in the tube 30 in the lower part of the bellows l0.'As will be described more fully in the succeeding remarks, this inhalation by the attendant of a quantity of his own exhaled air during each breathing cycle prevents the condition known-as hyperventilation in the attendant.

When the attendant subsequently forcibly exhales into the bellows, initiating a new inhalation cycle in the patient, the first air forced into the patients lungs comprises fresh air from the tube 30 within the bellows 10, together with a quantity of fresh air located in the lower portion of the bellows 10 below the tube 30. Thereafter, air from the lungs of the attendant is forced directly into the patients lungs, the end result being that the patient receives a mixture of fresh air with air exhaled from the attendants lungs. This type of resuscitation can be continued indefinitely, with the fluid distribution valve automatically assuming the proper position at each portion of the breathing cycle, and with this valve further functioning to prevent any movement of air from the patients lungs directly tendant.

For optimum operation of the subject resuscitator device as a mouth-to-mask resuscitator, it is preferred that the bellows 10 have an interior volume of approximately l000 cubic centimeters and that the tube 30, together with the lower portion of the bellows below the lower end of the tube 30 have a volume of approximately 300 cubic centimeters. Thus, during each inhalation cycle of the patient, the patient receives approximately 300 cubic centimeters of fresh air and during each inhalation cycle of the attendant, the attendant receives approximately 300 previously exhaled air which has high carbon dioxide content. This return of carbon dioxide to the lungs of the attendant avoids dizziness and hyperventilation of the attendant. lt is to be understood, of course, that the 1000 cubic centimeter and 300 cubic centimeter figures are not critical. The 1000 cubic centimeter volume of the entire bellows produces an overall size which is convenient for manual squeezing and wherein a sufiicient amount of air is displaced in each squeezing operation to accomplish a life sustaining respiration in the lungs of the patient. The total volume of the bellows 10 is other wise unimportant. Of course, the 300 cubic centimeters of retained air capacity created by the interior tube 30 has practical limits. If the retained air capacity substantially matched that of the attendant's inhalation and exhalation capacity, the patient would receive entirely fresh air. However, the attendant would receive only his own exhaled air and this would be obviously undesirable. Similarly, if the retained air capacity becomes too small, insufficient carbon dioxide is returned to the attendant's lungs to prevent hyperventilation.

It is to be recognized that the bellows 10 with its interiorly located tube 30 can serve a useful purpose in other applications than patient resuscitation. Thus, the bellows permits an individual to blow forcefully for. prolonged periods of time without encountering hyperventilation. It is, accordingly, use:

ful in the inflation of balloons or inflatable toys or inflatable boats, or the like. For such applications, the fluid distribution valve 86 may be replaced by any simple check valve, or, alternatively, the aperture 72 in the valve housing 14 plugged to enable inflation directly through the fitting 70 without removal of the fluid distribution valve 86. Thus, with reference to the bellows outlet port, the fluid distribution valve functions as a check valve, which permits fluids to leave the bellows, but prevents entry of fluids into the bellows.

In the preceding remarks, the operation of the subject resuscitator device has been described with reference to power supplied by an attendant, either in the form of manual manipulation of the bellows 10 or in the form of a forced exhalation of air from the attendant's lungs. It is to be recognized, however, that other sources ofpower may be utilized. For example, an adapter, similar to the plug l8 but having a conduit therethrough, may be inserted into the opening 47 leading to the inlet valve 44, and connected directly to a source of breathing gas which can be intermittently released into the bellows 10 to induce forced respiration of a patient.

While the device has been described with reference to operations in the ambient atmosphere, it will occur to those skilled in the art, that the subject device can be utilized for' pumping or displacing liquids as well as gases and can be operated for such purposes in numerous environments, in-

cluding under water. A particular benefit derived from the present construction is that each of the component parts of the device illustrated may be fabricated from noncorrosive elements. ln particular, the operation of the fluid distribution valve is governed solely by the pressures encountered in the normal breathing cycle and no springs or other biasing ele ments assisting the positioning of the fluid distribution valve are required. Thus, the need for metallic elements is entirely eliminated and contaminating chemical actions are precluded.

Although the preferred embodiments of .the device have been described, it will be understood that within the purview of this invention various changes may be made in the 'form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

I claim:

1. Apparatus adapted for alternative operation as a hand powered or as a lung powered pumping device comprising: a substantially hollow resilient .body having a fluid outlet port and a fluid inlet port spaced from said outlet port, first valve means disposed adjacent said fluid inlet port responsive to a fluid pressure within said body exceeding that outside said body to close said fluid inlet port, second valve means disposed adjacent said fluid outlet port responsive to a fluid pressure outside said body exceeding that within said body to close said outlet port, said resilient body having a third port therein spaced from said inlet and outlet ports, an elongate tubular element disposed internally of said body having one end encircling said third port and attached to the wall of said body and having its other end projecting through the interior of said body toward said outlet port, the interior volume of said tubular element togethervwith the interior volume of said body which is beyond the axial extent of said tubular element being less than one-half the entire interior volume of said body, and means to selectively open and close said third port, the construction and arrangement being such that with closure of said third port alternate application and relaxation of a compressive force to said body will result in an alternate expulsion of air from said body through said outlet port and intake of air into said body through said inlet port, and with opening of said third port an operator may repeatedly exhale air into and inhale air out of said resilient body through said third port thereby forcing air out of said outlet port during exhalation and drawing air through said inlet port during inhalation, said .tubular element retaining a portion of the operators exhaled air adjacent said third port for inhalation by the operator so as third port being disposed in one of said opposite ends, one of said fluid inlet and outlet ports being disposed in the other of said opposite ends, said tubular element extending from said one end of said body substantially coaxial with said longest axis toward the other end of said body, the other of said inlet and outlet ports being disposed in the wall of said body beyond the axial extent of said tubular element.

3. The apparatus of Claim 1 wherein said body has grooves disposed in the wall thereof adapted to receive the fingers and thumb of an operator.

4. The apparatus of Claim 1 whereinsaid means to selectively open and close said third port comprises removable means to close said third port.

5. The apparatus of Claim 1 wherein the interior volume of said body isnot substantially less than 1,000 cubic centimeters and the interior volume of said tubular element together with the interior volume of said body which is beyond the axial extend of saidtubular element is not substantially less than 300 cubic centimeters.

6. The apparatus of Claim 1 wherein said body is an elongate body and has a rotund cross section in substantially all planes normal to the longitudinal axis thereof, the wall of said body having a thickness in any said plane which tapers from a minimum at the opposite ends of one diametric axis of said body to a maximum at the opposite ends of another diametric axis of said body extending substantially normal to said one diametric axis whereby said body has two diametrically opposed axially extending sides of crescent shaped cross section joined by axially extending wall portions of minimum thickness, said crescent shaped sides yieldingly opposing compressive forces applied to said body at said wall portions of minimum thickness and thereby accumulating potential energy to restore the shape of said body upon release of said compressive forces.

7, The apparatus of Claim 6 wherein said wall portions of minimum thickness have circumferentially disposed grooves therein adapted to receive the fingers and thumb of an operator.

*zgz gg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,5 D t d December 22, 97

Inventor(s) Henry w'. Seeler, Deceased, Gerda-A Seeler It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 6, line 10, after "approximately 300", insert "cubic centimeters of his own-- Col. 8, lines 17 and 18, "extend" should be --extent-- Signed and sealed this 27th day of April 1971 (SEAL) Attest: l

EDWARD M.FI.ETGHER,JR. WILLIAM E. SCHUYLER, JR.

A'ttesting Officer Commissioner of Patents