US3405938A

US3405938A - Gymnastic device providing noncircular support movements

Info

Publication number: US3405938A
Application number: US439273A
Authority: US
Inventors: Max M Aydelott
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-03-12
Filing date: 1965-03-12
Publication date: 1968-10-15
Anticipated expiration: 1985-10-15

Description

Oct. 15, 1968 M. AYDELOTT 3,405,938

GYMNASTlC DEVICE PROVIDING NON'CIRCULAR SUPPORT MOVEMENTS Filed March 12, 1965 3 Sheets-Sheet 1 15%,], 5'5 74 pm 32 32 5o42j3 a 6 as 75- 55 Oct. 15, 1968 M. M. AYDELOTT 3,405,938

GYMNASTlC BEVICE PROVIDING NON-CIRCULAR SUPPORT MOVEMENTS Filed March 12, 1965 5 Sheets-Sheet 2 Oct. 15, 1968 M. M. AYDELOTT 3,405,938

GYMNASTIC DEVICE PROVIDING NON-CIRCULAR SUPPORT MOVEMENTS Filed March 12, 1965 5 Sheets-Sheet 5 lama/729R MAX LM. A YDEL 0T7;

United States Patent 3,405,938 GYMNASTIC DEVICE PROVIDING NON- CIRCULAR SUPPORT MOVEMENTS Max M. Aydelott, 1029 S, Glenview Road,

, West Covina, Calif. .91790 Filed Mar. 12, 1965, Ser. No. 439,273 18 Claims. (Cl. 27261) ABSTRACT OF THE DISCLOSURE -A rigid frame is movably mounted so that two spaced parallel axes on the frame are constrained toswing in circular paths about respective-parallel axes on a fixed support.

Body supporting elements, typically transverse bars, are provided on the frame at points spaced from the frame axes, such that the elements move along distinctively different but positively coordinated non-circular paths. By shifting his weightfrom one element to another, the user can produce controlled frame movement.

This invention has to do with gymnastic apparatus in which one or more body-supporting elements are mounted for movement along respective definite and essentially positively defined movement paths in response to the weight or momentum of the users body.

Whereas conventional gymnastic devices utilize fixed bility for movement is preferably sodesigned as to leave ample space below the movement paths of the barsfor the. user to hang and swing freely from them.

One aspect of the invention provides a single bodysupporting element that is capable of oscillatory movement along a path that includes a generally horizontal midportion with upwardly curving end portions. Such a path may approximate a portion of an oval orellipse with its major axis generally horizontal. Such oscillation may be considered to be derived from the arcuate path of a trapeze by causing the radius of curvature .to vary along the path. The radius of curvature at the central portion of such a path may be essentially infinite, while at the end portions it typically becomes quite small.

A further aspect of the invention provides two ,or more mutually spaced body supporting elements that are movable along respective paths in a positively coordinated manner. Such paths are preferably widely different, in their nature, so that the movements of the respective elements respond differently to the weight of'the user. For example, two such paths may be so related that a predominantly horizontal portion of one path corresponds to a predominantly vertical portion of the other.

A particularly interesting form of the invention provides three or more spaced parallel bars mounted in a mutual spatial relation similar to the parallel edges of a prism and forming a rigid frame assembly. The supporting structure may then be arranged to permit continuous rotary movement of the frame assembly, that rotation being coordinated with a definite pattern of oscillatory movement defined by the support. With such a device, the user may grasp the bars successively, walk ing around the frame with his hands, while his body swings freely in response to the oscillatory frame movement. Alternatively, with suitable dimensioning of *the' prismatic figure formed by the spaced bars, theuser can support his body on the bars within the prism, and

can cause the frame to rotate oroscillate by shifting his Weight about within it. By arranging theseveral bars to follow distinctively different paths, as will be more fully described, such a device may provide a wide variety of interactions between the weight and inertia of the users" body and the movements of the respective bars."

A further aspect-of the invention provides'o'neor more support elements having movement'paths of the type described, from which a fiex'ible body supporting device is suspended. One formof such device comprises a rigid frame swingably supported on a horizontal bar'of the type described. The swinging movement of the frame then adds further variety to the non-circular movement path of the barJAnother form of such device comprises a flexible web such as a piece of canvas or other suitable cloth resembling a hammock and suspended along two opposite edges from two generally parallel bars having puting Mechanisms and Linkages, 1948, which is volume 27 of the Massachusetts Institute of Technology Radia- 9 tion Laboratory Series, McGraw-Hill, 1948. The two links adjacent the fixed base act primarily as supporting links, while the link opposite the base will be referred to as the coupler or working link. One or more body supporting elements are mounted on the Working link in the desired mutual relationship, and such elements may also be mounted if desired on the supporting links. The relative lengths of the four links and the positions of the body supporting elements with respect to the pivot axes of the working link are -so selected as to give those elements the desired movement capability. Many techniques are available for designing four-bar linkages to give a desired movement pattern. See, for example, Product Engineering for Sept: 19,1960, pp. 76-80, and the further references contained therein.

A further aspectof the inven-ion provides yielding means for biasing the movement of the linkage in a selected direction, or toward or away from selected positions. Such biasing is particularly useful for balancing the weight of the linkage elements themselves. If such counterbalancing of the device is complete, the apparatus may appear to the user to be entirely free of bias. The body supporting elements then move equally freely in either direction along their defined pahs, subject to only to inertia and friction. Alternatively, a yielding bias may be introduced to slow down or speed up certain portions of the movement pattern, or to effectively limit the move-' of the weight of sides of the working area. The support. links of each such pair may be structurally independent; or they may be integrated, for example as a unitary frame of U-form,

the coupling structure being so located as not to interfere with the working area.

In either case, the invention may provide a structural arrangement of the working or coupler link that permits its continuous rotation without interference with the supporting links. Alternatively, the working link may be limited, if preferred, to oscillatory movement, for example through some definite angle in each direction from a central position. Resilient stops may be provided at the ends of such rocking movement to cushion the action and to provide an impulse to initiate return movement in the opposite direction.

The invention further permits adequate spacing of the support links from each other and from the frame assembly in an axial direction with respect to the Pivot axes. Such spacing is preferably sufficient in all positions of the apparatus to freely receive the body of a person using the device, thereby preventing injury.

The apparatus of the present invention may be combined in many different ways with known apparatus of various types. As an example, the present gymnastic apparatus may be mounted above a trampoline, so that a gymnast may use them in any desired coordinated manner. Additional body supporting elements may be mounted on any desired members of the present apparatus. For example, one or more rings or bars may be mounted in fixed or movable relation to the support links or their equivalent either directly or by means of brackets in position to have a desired relative movement with respect to the main working frame assembly.

Many other changes and modifications can be made in the specific structures herein described without departing from the proper scope of the present invention.

A full understanding of the invention will be had from the following description of certain illustrative manners in which it may be carried out. The particulars of that description, and of the accompanying drawings which form a part of it, are intended only as illustration and not as a limitation upon the scope of the invention, which is defined in the appended claims.

In the drawings:

FIG. 1 is a schematic drawing representing an illustrative four-bar linkage;

FIG. 2 is a side elevation representing an illustrative embodiment of the invention;

FIG. 3 is an end elevation corresponding to FIG. 2;

FIG. 4 is a plan corresponding to FIGS. 2 and 3;

FIG. 5 is a fragmentary elevation corresponding to FIG. 2 and representing a modification;

FIG. 6 is a perspective representing a further modification;

FIG. 7 is a side elevation representing a further modification;

FIG. 8 is an end elevation corresponding to FIG. 7;

FIG. 9 is a side elevation representing a further modification; and

FIG. 10 is a perspective representing a further modification.

The schematic drawing of FIG. 1 represents a four-bar linkage of an illustrative type that is useful in carrying out the present invention. In that linkage the base link is horizontal and may be considered fixedly mounted on the ground. The two support links and are pivoted on fixed base link 20 on the respective horizontal pivot axes 31 and 41 perpendicular to the plane of the drawing. The coupler link 50 is pivotally connected to the free ends of

support links

30 and 40 on the coupling axes 32 and 42, respectively. Coupler link 50 may be of any desired form, being shown triangular in FIG. 1 with apex 52 offset from the plane of

axes

32 and 42.

Such a linkage has only one degree of freedom, comprising coordinated swinging movement of the two support links about their connections to base link 20 and simultaneous coordinated swinging of coupler link with respect to the support links at

axes

32 and 42. The arcuate paths described by coupler axes 34 and 44 are indicated schematically at 38 and 48, respectively. The illustrative linkage of FIG. 1 is symmetrical about a vertical plane of symmetry indicated at 22, the two support links being of equal length. The linkage is shown in solid lines in its unfolded symmetrical position, which may be considered its normal or rest position for purposes of reference.

FIG. 1 also shows in dashed lines two deflected positions of the linkage, a rightward deflected position denoted by the subscript a and a leftward deflected position denoted by the subscript b. In position a the coupler link is approaching aligned relation with the trailing support link, which is link 30. In position b the coupler link has rotated more than 90 from rest position, and the two support links appear crossed. In those two deflected positions, which are merely illustrative, coupler apex 52 is shown at 52a and 52b, respectively. The continuous series of possible intermediate linkage positions carry point 52 along the closed path indicated schematically at 53. That path may be seen to comprise a substantially rectilinear lower horizontal portion 54, a gently curved upper portion 55 and relatively sharply curved end portions 56 and 57. Due to the symmetry of the present structure, those end portions are identical except that one is the mirror image of the other.

FIGS. 2 to 4 represent an illustrative practical embodiment of the invention, which may be considered to be derived in part from the linkage of FIG. 1, corresponding parts being designated by the same numerals. The single linkage structure indicated in FIG. 1 is essentially duplicated, providing two functionally identical linkages in spaced parallel planes on opposite sides of the working area. The base links of those two linkages are fixedly mounted on the ground with their

base axes

31 and 41 mutually aligned. The coupler links of the two linkages are essentially unitary with their

coupler axes

32 and 42 respectively aligned.

Base 20 comprises four pipe sections of general L-form, each having one leg 25 of the L fixedly anchored in the ground 23, as by setting in concrete. The other leg 26 of each L extends horizontally spaced above the ground and carries at its free end a bearing structure 24. Those bearings are aligned in pairs defining the parallel base axes 31 and 41. Horizontal portions 26 of the base provide a slight vertical spring to the action of the device, as well as carrying the actual anchor structures away from the working area.

Support links 30 and 40 typically comprise sections of pipe with modified T-fittings at their ends to provide hearing structures. The lower bearings 34 and 44 engage base bearing structures 24, while

upper bearings

35 and 45 engage similar bearing structures formed on the frame assembly 60 at 64 and 65. The latter bearing structures are alined in pairs and define the two parallel coupler axes 32 and 42. Bearings 65 are spaced slightly more closely on axis 42 than the corresponding bearings at the base of support links 40, so that the latter are slanted outward at the base as seen in FIG. 3, giving increased stability. The support links of one pair shown as links 30, are mutually spaced more closely in an axial direction at their upper ends than the links of the other pair, and have diagonal offsets 37 intermediate their length which bring their lower end portions into the same plane as the links 40. That arrangement provides uniformity of the base structures, while insuring ample space between adjacent support links to receive the body of a person using the apparatus without danger of injury, particularly when the links are in crossed position as in the leftward deflected position shown at b in FIG. 2. If preferred, support links 30 may be identical with links 40, their support pivot bearings then being spaced more closely together than those of links 40. l

The bearing

structures

64 and 65 on frame assembly 60' are so arranged that the support links can swing freely without interfering with each other or with that assembly. For that purpose it is convenient to form each axial end portion of frame assembly 60 as a crank 62 that connects the two bearing

structures

64 and 65. The two-axially inner bearing structures 64 are fixedly joined together by structure of any desired form that carries or comprises the body supporting elements of the device.

In the present frame assembly, that connecting structure includes the stub shafts 63, which extend toward each other from bearings 64 in alinement with coupler axis 32, and the four

parallel bars

72, 74, 76 and 78 which are fixedly mounted on those stub shafts by the

radially extending struts

73, 75, 77 and 79, respectively. Those bars comprise the primary body supporting elements of the device.

Bars

72 and 74 are shown illustratively (FIG. 3) as having only a short straight section between the curves that join the supporting

struts

73 and 75. The entire bar structure-may be curved, if desired. The form of

bars

76 and 78, shown best in FIG. 4, is generally preferable, providing a longer section that is essentially straight. The four bars are arranged symmetrically in the form of a diamond, centered on the axis of symmetry 67, which is half way between coupler axes 32 and 42. However, since stub shafts 63 are on axis 32 rather than on axis '67, struts 73 and 75 are slightly oblique, as shown best in FIG. 2. If it is preferred to maintain

struts

73 and 75 in the common plane of

bars

72 and 74, they may be mounted on struts 79 at axis 67, rather than directly on stub shafts 63. The structure may then be strengthened as necessary to compensate for such modification. Or stub shafts 63 'may be of crank form, with their opposed ends on axis of symmetry 67.

FIG. 2 shows in solid lines the normal or symmetrical position of the linkage and indicates in dashed lines two illustrative deflected positions which correspond generally to deflected positions a and b of FIG. 1. The arcuate paths of coupler axes 32 and 42 are indicated at 38 and 48, respectively. The path of bar 72 during the entire cycle of possible movement of the device is indicated at 72P, and will be seen .to have the same general characteristics already described for path 53 of FIG; '1. However, the detailed proportions and form of the path are different, corresponding to the somewhat'diiferent relative dimensions in the two figures. Many further modifications of that general path form may be obtained by suitable variation of the linkage proportions, including the position of bar 72 with respect to the coupler axes.

FIG. 2 also indicates in dashed lines the paths of the other bars, each path being denoted by the numeral for the bar followed by the letter P. The path 74P for bar 74 is generally vertical with a large and fairly wide upper loop and a much smaller lower loop, which is described in reverse direction. The paths for

bars

76 and 78 are mirror images of each other, approximating greatly elongated ellipses with their major axes oppositely inclined with respect to gravity. The several paths of the respective bars thus provide a wide diversity of pattern forms, illustrating the great variety of movements obtainable by the invention.

In the present embodiment the

bars

72, 74, 76 and 78 and their supporting struts form a cage structure having the general form of a prism, with the bars at the intersections of the prism faces. The user of the device, in addition to hanging from a single selected bar, can move his body about either inside or outside of that frame or cage, typically grasping one or more of the bars with his hands and supporting his feet or knees on the others. He can thus shift his Weight with respect to the effective axis of rotation of the cage structure, or, more exactly, with respect to the vertical plane through that axis, since weight applied to the frame at that plane does not tend to cause frame displacement in either direction. The instantaneous center of rotation of the coupler link frame assembly 60 is at the intersection of the plane of support links 30 and the plane of support links 40. For example, for the deflected positions a and b of FIG. 2 the axes of effective rotation are indicated at 81 and 82; respectively. If a vertical plane is visualized passing through each of those axes of rotation, the distance of'the center of mass of the users body from that plane gives a measure of the direction and magnitude of the effective torque due to his weight tending to move the apparatus. For example, if his weight is centered at axis of symmetry 67,'it will be seen to exert on frame 60 in position a a relatively large counterclockwise torque with respect to axis. 81, tending to swing the" device farther from its rest position. In position b, the same body position in the frame exerts a relatively small counterclockwise torque with respect to axis '82, tending in that position to increase the deflection from rest position. For that particular body position, the device thus provides positions of stable equilibrium close to its positions of extreme deflection in both directions, as wellas a position of unstable equilibrium at the rest position shown in solid lines. However, the corresponding results for any other body position depend quite sensitively upon the selected position. The variety and interest provided by the device results in large part from the dependence of its response upon the selected body position, both as that position is varied, as from one bar to another, and, for a given body position, as the machine itself moves.

Although the working region during use of the device is normally limited essentially to the space between the two planes perpendicular to the coupler axes at the respective ends of the working bars, the users body may also swing axially outward of the struts either intentionally or otherwise.- It is therefore desirable, in order'to prevent possibility of injury, that there be adequate space to receive the users body between those struts and support links 30, and also between support links 30 and links 40. That is accomplished in the present structure, asseen clearly in FIG. 3, by spacing the support links axially from each other and from the struts, at least near their upper ends. The lower portions of the support links 30 and 40 can safely lie in or near a common axial plane, as shown, since the separation of the support axes-prevents those portions of the links from approaching each other in any case.

With respect to operation of the described apparatus links-30'may be considered to mount frame assembly 60 for rotation about coupler axis 32 and for simultaneous swinging movement of that axis about support axis 31; and links 40 may then be considered as a mechanism for defining the rotational position of the frame assembly about coupler axis 32 as a [function of the swinging movement of that axis about support axis 31. From that viewpoint, the distinct functions of the two sets of links are interchangeable. Alternatively, links 30 and links 40 may be considered as two mechanisms acting independently of each other to mount the frame assembly for rotation about the associated

coupler axis

32 or 42 and for simultaneous swinging movement of that axis about the

support axis

31 or 41. From that-viewpoint the actual frame movement results from the cooperation of two co-equal linkage systems. Similar alternative viewpoints are applicable also to the further specific embodiments to be described.

The swinging movements of the two link systems about their respective support axes are limited to definite angular ranges, which are equal in the present embodiment. Beyond those ranges the

arcuate paths

38 and 48 of'the coupler axes (FIG; 2) are farther apart than the spacing between the two

coupler axes

32 and 42, which is set by the structure coupler of frame 60. Such limitation will occur, for the present general arrangement, whenever the separation of the support axes exceeds the separation of the coupler axes plus the difference, if any, between the eflective lengths of the two link systems. For other arrangements of the support and coupler axes, different but generally corresponding conditions apply.

The arrangement of the body supporting bars in the embodiment of FIGS. 2 to 4 is subject to many modifications. In particular, one or more of the illustrated bars may be omitted, or additional bars may be added as desired, thereby changing the spacing between adjacent bars. The circumferential spacing of the bars is especially significant when the user swings by his hands from one bar to the next, causing the frame to rotate and oscillate as the weight is shifted from bar to bar around the prism. The detailed position of each bar, especially its radius from axis 67, may be selected to give the desired movement pattern for that particular bar. As already indicated, when several ,bars are provided, it is usually desirable to include a variety of widely different movement patterns. The bars may be of any desired length, provided, of course, that the mechanical design be made sufficiently strong. a

The base frames 20 can omit the L-form shown in FIGS. 2 to 4. For example, the base bearings on

support axes

31 and 41 might be mounted directly on vertical posts anchored firmly in the ground. And those axes need not be above ground level. In fact, some or all of the base bearings may be set below ground level, if desired, as in respective wells that allow ample clearance for the swinging movement of the support links. Also, the base may comprise a structure anchored to the floor or other surface by suction cups or the like.

FIG. 5 represents a modification of the structure of FIGS. 2 to 4, wherein the frame assembly 60A has only two horizontal bars at 76A and 78A supported on the struts 76A and 79A, respectively, between which there is suspended a flexible hammock-like structure indicated at 70. Hammock 70 may comprise a single sheet of canvas or the like loosely draped between the parallel straight bars 76A and 78A and with its side edges secured to them in any conventional manner, as by lacing through grommets in the cloth. End pieces 71 may be added to prevent a user from slipping out an open end of the curved canvas. In the present embodiment the bars are appreciably below the plane of the coupler axes. The respective paths of the bars are indicated at 76P and 78F, and correspond with modifications to the lower portions of the paths with the same numerals in FIG. 2. The upper portions of the bar paths are not normally used in the present device. Two illustrative deflected positions of the frame assembly are indicated schematicallyplt will be noted that the lowest point of the loosely hanging hammock tends to be lower at those deflected positions than in the central position shown in solid lines. Thus the latter is typically a position of unstable equilibrium if the user allows his body to roll freely from side to side of the hammock. On the other hand, if the user centers his weight near the outer edge of the hammock in its deflected position, the apparatus tends to be returned toward its central position. The hammock can thus be operated somewhat like a swing, but with quite different detailed operation that is novel and interesting. Additional bars may be provided if desired, for example one corresponding to bar 74 of FIG. 2 which can be grasped by the user while his body rests in the hammock.

FIG. 6 represents in perspective a modification in which the two sets of support links 301 and 401 are of different lengths, making the linkage unsymmetrical and producing movement patterns of the working bars that are also typically somewhat unsymmetrical. The two support links of each set are joined together by coupling members 36 and 46 which act as swing shafts and are journaled on

support axes

31 and 41. The base structure in FIG. 6 comprises four posts 27, which are joined in pairs by sections 27a buried in the ground, and which carry bearing structures 28 for shafts 36 and 46.

The coupler link in FIG. 6 comprises a frame assembly .8 601 with a continuous shaft 631 carrying crank formations 621 at both its ends. Those crank formations provide bearings for links 301 on coupler axis 32 and for links 401 on coupler axis 42. The

arcs

38 and 48 represent the paths of respective points on those axes midway between the coupler bearings. In the present embodiment only two primary body supporting elements are'provided, comprising the

bars

84 and 86 which are mo'untedon shaft 631 by means of the'radial struts. 83. The bars are parallel to shaft 631 and spaced therefrom diametrically opposite each other in a plane that is 0blique with respect to the plane of the two

coupler axes

32 and 42. That placement of the working bars provides interesting movements and has the further advantage of retaining. a simple and symmetrical arrangement of the parts. The central portion of shaft 631 and also the radial struts 83 may be employed also as body supporting elements if desired.

The apparatus in FIG. 6 is shown. in solid lines near the right end of its movement pattern, not in a central position as in FIG. 2. FIG. 6 also indicates in dashed lines a position of the device near the left end of its pattern. The line represents the approximate path of the midpoint of bar 84; line 87 that of the midpoint of bar 86. It will be seen that those paths correspondbroadly to paths 72F and 74P of FIG. 2. Despite the appreciable unsymmetry of the linkage, the two paths are approximately symmetrical with respect to a vertical plane parallel to the axes of the device and displaced somewhat to the left of support axis 31. The present embodiment thus provides an offset of the main linkage structure to one end of the main working area, which permits greater freedom of movement of the user, especially within the range of movement of the device near the left position indicated in FIG. 6.

Especially with an offset linkage of the type shown in.

FIG. 6, it is sometimes desirable to provide means for counterbalancing part or all of the weight of the mechanism itself. A convenient form of counterbalancing mechanism is illustrated by the two coil springs 90, which interconnect selected points of the support links. Brackets 91 are mounted on those links to facilitate connection of the springs, and a plurality of holes 92 or equivalent formations are preferably distributed longitudinally of those brackets to permit selection of the points of connection to give the desired resilient action. With the springs mounted as illustrated at points closer to the support axis on links 401 than on links 301, the springs tend to swing the links toward the right in FIG. 6, partially or wholly counteracting the opposite tendency of the weight of the support links themselves. It may be noted that the weight of shaft 631 also tends to urge leftward movement or extension of the structure, since that shaft moves generally downward as the linkage swings toward the left. On the other hand, the effect of the weight of the users body when hanging from

bar

84 or 86 is derivable from the bar movement path independently of the offset of the linkage. Thus, for example, since the lower portion of path 85 of bar 84 is essentially horizontal, a weight applied to that bar does not bias it in either direction along that portion of its path.

Biasing force can be obtained alternatively by mounting one or more counterweights on any of the movable links in position to produce the desired lever arm with respect to a linkage axis. .For example, the weights 104 are mounted on support links 401 in FIG. 6 by means of the struts 105 in position to produce a clockwise torque about support axis 41. Such weights may be coupled to the support links in a manner permitting swinging movement about the longitudinal axis of the link. When swung into such position as indicated at 10411, with strut 105 parallel to axis 41, the biasing action of the weight is virtually zero. The bias is thereby made conveniently adjustable.

FIGS. 7 and 8 illustrate a further embodiment of the invention, in which the two

support axes

31 and 41 are horizontal, as before, but li ih a common plane that is essentially-vertical rather than horizontalJSuch an arrangement is well suited, forexample to-mounting on a wall 29 of a gymnasium or the like. 1

.-,The present embod ment .further illustrates the use of resilient elements in place of normal bearingstructures to mount the supportlinks for swinging movement about the support axes. The helical springs 94 and 96 have their upper ends fixedly mounted coaxially of the respective support links and their ,lower ends fixedlymounted in essentially, vertical position on the stationary. brackets are thus typically .pr estressed in .a-.:manner'to urge the links towardverticalv position. By suitablerselection of the spring-constants; such mounting'can be designed to counterbalance theweight of the links essentially completely; and to balance also any desiredportionofthe weight of the coupler mechanism to a very'good approximation. The behaviorof the device during use isthen essentially independent of the rather extreme otfsetof'the linkage.

The.longitudinalrcompressibilityof springs94 and '96 permits slight translational movement of the support links parallel to their lengths in addition to their primary swinging movement. Moreover, the effective support axes 31 and 41 for the swinging movement are not positively defined; but shift; their. positions slightly as. the links swing. The positions of the support axes also vary slightly in response to variations in the longitudinal compression ofthe springs. Those effects combine to give the entire apparatus a slight resilience'in use. The respectivepaths of the working 'bars are therefore not positivelydefined, but vary in response to such factors as the weight and inertia of the usersbody. That resilience can'be made quite appreciable, if desired, adding a further element. of va riety andinterestto the operation of the'deviceiFoithe sake. ofrclarity, liowever,1such lack of positive definition of the movement of the working bars will .be disregarded for the most part in the present drawings and. description.

The coupler-mechanism in the. present embodiment employs a continuous shaftmember632, functionally similarto rnember63l of FIG. 6, but considerably longer.

FIGS. 7 and 8 further illustrate introduction of a yieldingbiastending to return the device to a predetermined equilibrium position in absence of the weight of a user. Such biasing means is represented by the spiral leaf spring 110, the inner end of which ismounted on an extension 111 of shaft 632 outward of link 402. The

; rapid than that of the link, and is in the opposite direc- Two parallel working bars.98'anda99'are fixedly mounted on shaft 632 bymeans of the-radially extendingstrhts 100 and the brackets-101.:Bars- 98 and 99 are parallel to each other. and to 'the'coupler axes, and are spaced generally-horizontally from each other. That spacing is small compared to their distance from shaft 632. Typical movement paths for the,.-respective barsr-are indicated in FIG. 7;.at- 98P-and-99P. Each path hasa-rnearly straight central portion with smoothly upcurving end-"portions,v the central portions being slightly inclined to the horizontal in opposite directions. It is thus possible to inducemovement of'the. bars in eitherndirection along the central portion of their paths by shifting weight from one bar to the other. The relative inclination of .the two paths may be altered withinl wide limits by varying the spacing between the bars. p:

The present embodiment further illustrates the combination of a gymnastic device of the-type that has been described with known types of exercise devices, represented illustratively in FIGS. 7. and 8 by the trampoline 108-positionedbelow the working area. The trampoline typically comprises a sheet of canvas or the like 107 supportedbya plurality of ropes 106 at points distributed about its periphery, the ropes being tensioned by .curved".

leaf springs 109 which may be bolted directly to the floor. Trampoline 108 is positioned at a suitable distance below the working

bars

98 and 99 to permit the user'to grasp the has only nejar -the top of anormalu-jump'from the trampoline-.-After swinging on one orboth bars while causing them to move over any desired portion of their spring back'to;the bars either directly or after any desired available paths, he can drop to the trampoline andthen numberof trampoline figures. Such an auxiliary device can usefully be employed with any of the presently described embodiments.

outer end'of spring 110 is securedto that link asby means of the bolt indicated at 112. The mounting of spring 110 on shaft extension 111 preferably employs a friction clamp of conventional. type that can be released i and secured in any desired angular relation to the shaft, 25 and 91, :whichimay be of anysuitable type. The. springsdesired, .by connecting bolt 112 to the spring by means of a simple'clampbracket that is shiftable along the length of the spring. It'will be noted thatduring swinging movement of support link 402 corresponding to-the indicated range of barmovement the rotationof shaft 632 is .more

tion. Hence a biasing spring that acts between the shaft and linkas shown. requires less torque to produce a given eifectivebias than would be needed in a spring acting between link 402 and the fixed base, for example.

It will be evident that the gymnastic apparatus of the invention might be mounted on the ceiling of a. room, rather than on the floor or wall. For example, one of the embodiments that has been described may be turned through 180-and suspended from above. That would, of

course, invert the indicated movement paths of the various body supporting elements. If different paths are desired,-

the linkage may be redesigned to provide them.

FIG. 9 represents in schematic perspective a modification utilizing a symmetrical linkage in which the two sup- .port axes 31 and 41 lie in a common vertical plane. This form differs from those described above in that the

paths

38 and 48 of couples axes 32 and 42 do not cross within the working range. As a consequence the frame assembly does not rotate continuously, but rocks back and forth vwhile oscillating from side to side. The frame assembly is shown at. one extreme of that oscillation. Frame assembly 603 comprises two'coupler'link members 632 fixedly connected by the working bars and 122. Each of the members 632 is coupled to one of thebase posts 124 by the two

support links

303 and 403. Typical paths for the two bars are indicated schematically at 120P and 122P, which represent the paths of the lefthand ends ofthe respective bars as seen in FIG. 9. Those paths are of inclined oval shape, and their upper portions overlapv somewhat. The present structure is typically made of suchv size that the lower extremities of the two bar paths are two or three feet apart, and the posts 124 are of suchheight that the head of a man standing on the ground comes somewhat below axis 41. By gripping one bar with each hand the user can then suspend his body, swinging from side to side as he pulls downward on first one bar and then the other. That novel action is excellent exercise for the arms and shoulders. Due to that relatively small size, and to the nature of the linkage, the two support links on each side need not be spaced apart as generously as in the previously described forms. However, such spacing as indicated in the figure is generally desirable.

FIG. 10 illustratessupport of the working bars on a single linkage structure, in contrast to the use of two spaced structures as in the previous embodiments. Support link 305 is shown as'a singlemember, with a gooseneck at its upper end. Support link 405 is constructed of two spaced members for strength and also to obtain a forked structure at its upper end. The lower portion of thelink might be a single .beam, if preferred. The support links aremounted for swinging movement about the fixed support axes 31 and 41, link 305 working between the two arms of link 405. Frame assembly 605 comprises the shaft 635 having two spaced portions journaled on coupler axis 42 on the respective arms of link 405 and fixedly connected by the crank formation 625 which is journaled on link 305 on coupler axis 32. Body supporting elements of any desired type may be mounted on one or both of the ends of shaft 635. As shown, each end of the shaft carriers a diametral cross arm 126 with parallel bars 128 mounted on its respective ends. The device can then be used by two persons at the same time, who may coordinate their actions or may work in competition with each other. Alternatively, a single person may use either set of bars in the same manner as the previously described embodiments.

Bars 128 typically lie close to the plane of crank 625. The movement paths of the bars are then of the general nature of oblique paths 76F and 78P of FIG 2. Greater variety may be provided by making the movement paths of the two sets of bars somewhat different, while still preferably retaining general similarity between them so that the actions of two gymnasts using the respective sets will be mutually related in an orderly manner. That can be done, for example, by angularly positioning arms 126 oppositely oblique with respect to the plane of crank 625 by an angle of the order of 15 The inclination of the paths of the bars of one set is then steeper than that of the other. If desired, the arms 126 or other supporting structure may be mounted on shaft 635 with a lock nut or other conventional device that can be released to permit adjustment of the angular position and then tightened to lock that position securely for use.

The two arms of support link 405 may be widely enough spaced to receive the users body between them and crank 625 without injury. Alternatively, a protective shield or housing of wire mesh or sheet material may be mounted in a manner to positively prevent a user of the device from becoming caught between any members of the crank and link mechanism. Such a housing is illustratively shown at 130 in FIG. 10, with the cylindrical wall 132 and with the two circular end walls 134 adjacent the respective struts 126 and centered on shaft 635. Cylindrical wall 132 is apertured at the two arms of support link 405, and is provided with a clearance slot 136 for link 305. That slot may be effectively closed, if desired, by a shield of cylindrical form, not shown, that is telescopically related to wall 134 and that slides on link 305. Similar protective devices may be provided, if desired, in connection with other embodiments, but it is ordinarily preferred to design the structure in such a way as to be inherently safe.

As already indicated, it is sometimes desirable to mount a biasing weight on the coupling link assembly, rather than on a supportlink as illustrated at 401 in FIG. 6. When the working bars of the device are formed of tubing, such a biasing mass may be provided conveniently by filling the interior of such tubing partially or wholly with a heavy material, such, for example, as lead. Such a mass can be provided only in one or more selected bars to bias the device toward those positions in which the selected bars are lowest; or the mass can be distributed among symmetrically placed bars, for example in a device such as that of FIGS. 2 to 4, to increase the effective moment of inertia of the device with little or no biasing action. The movements of the device in response to changes of position of the user are then less abrupt, and the device tends to move more smoothly and uniformly.

I claim: 1. A gymnastic device comprising in combination support means fixed relative to the ground, an essentially rigid frame assembly including structure defining an axis, first coupling means rotatably supporting the frame assembly on said axis for oscillatory movement with respect to the support means along a predetermined path parallel to a vertical plane, second coupling means interconnecting the frame assembly and the support means for producing rotation of the frame assembly about said axis in definitely predetermined correlation with said oscillatory movement, and at least one body supporting element mounted on 5 the frame assembly spaced fros said axis and having such spatial relation to the ground as to be grasped by a user for free suspension of his body therefrom in all positions of the frame assembly.

2. A gymnastic device as defined in claim 1, and wherein said body supporting element comprises a bar fixedly mounted on the frame assembly generally parallel to said axis and transversely spaced therefrom.

'3. A gymnastic device as defined in claim 2, and wherein the position of the bar on the frame assembly is so related to said oscillatory movement of the axis and to said rotary movement of the frame assembly about the axis that the bar moves along a predetermined path that has a generally horizontal intermediate portion with smoothly upcurving end portions.

4. A gymnastic device as defined in claim 2, and including also a second bar fixedly mounted on the frame assembly generally parallel to said axis and transversely spaced therefrom and from the first said bar,

said oscillatory and rotary movements of the frame assembly causing the bars to move along respective predetermined noncircular curved paths in definite mutual correlation.

5. A gymnastic device as defined in claim 4, and wherein the positions of the bars on the frame assembly are so related to said oscillatory movement of the axis and to said rotary movement of the frame assembly about the axis that the path of one bar has a generally horizontal intermediate portion with smoothly upcurving end portions, and the path of the other bar extends predominantly vertically and intermediate the end portions of the path of said one bar.

6. A gymnastic device comprising in combination support means including structure defining two horizontal mutually spaced parallel support axes, an essentially rigid frame assembly including structure defining two mutually spaced parallel coupler axes,

linkage means constraining the coupler axes to swinging movement about the respective support axes at predetermined respective radii, the difference between said radii being less than a predetermined value,

the distance between the support axes exceeding the distance between the coupler axes plus said value and the linkage means permitting continuous rotation of the frame assembly,

and the frame assembly including at least one body supporting element spaced from said coupler axes and in position to be grasped by a user for sus nsion of his body therefrom.

7. A gymnastic device as defined in claim 6, and wherein said radii difier by a distance greater than the distance between said coupler axes.

8. A gymnastic device as defined in claim 6, and wherein said frame assembly includes a plurality of spaced parallel bars enclosing a space capable of freely receiving a users body.

9. A gymnastic device as defined in claim 6, and wherein said frame assembly comprises a plurality of mutually parallel spaced bars,

bracket means interconnecting the bars at their opposite ends, two shaft elements extending outwardly from the respective bracket means in mutually alined relation and defining one of said coupler axes,

and structure mounted on the respective shaft elements and defining the other coupler axis.

10. A gymnastic device as defined in claim 6, and wherein said frame assembly comprises a shaft coaxial with one coupler axis and having intermediate its length a crank forming offset coaxial with the other coupler axis,

bracket means mounted on at least one end of the shaft,

said body supporting bar being mounted on the bracket means and extending generally parallel to the shaft axis and offset radially and axially therefrom.

11. A gymnastic device comprising in combination an essentially rigid frame assembly comprising shaft means including two coaxial first bearing formations defining a first coupler axis,

a plurality of body supporting bars fixedly mounted on the shaft means in spaced parallel relation to the axis and to each other, the ends of the bars being spaced axially inward of the bearing formations,

and two second coaxial bearing formations mounted on the shaft means axially outward of the respective first bearing formations and radially offset therefrom and defining a second coupler axis parallel to the first coupler axis,

support means including structure defining two spaced parallel support axes,

two first link arms swingably mounted on the support means on one support axis and engaging the respective first bearing formations for mounting the frame assembly for rotation about the first coupler axis and for swinging movement of the first coupler axis about said one support axis in parallel spaced relation thereto,

and two second link arms swingably mounted on the support means on the other support axis and engaging the respective second bearing formations for mounting the frame assembly for rotation about the second coupler axis and for swinging movement of the second coupler axis about said other support axis in parallel spaced relation thereto.

12. A gymnastic device as defined in claim 11, and

wherein said first link arms are spaced axially outward of the respective opposite ends of said bars by a distance at least substantially equal to the thickness of a human body,

and at least the portions of said second link arms adjacent the second coupler axis are spaced axially outward of the respective first link arms by a distance at least substantially equal to the thickness of a human body.

13. A gymnastic device as defined in claim 11, and wherein said shaft means comprise two stub shafts associated with the respective first bearing formations, and said plurality of bars have their opposite ends mounted on the respective stub shafts and constitute the only connection therebetween.

14. A gymnastic device as defined in claim 11, and wherein said shaft means comprise a shaft element continuously interconnecting the first bearing informations.

15. A gymnastic device as defined in claim 11, and including also resilient means engaging at least one of the link arms for yieldingly biasing the frame assembly movement.

15. A gymnastic device as defined in claim 11, and wherein the length of the first link arms is different from the length of the second link arms,

said device including resilient means and structure for interconnecting the resilient means between variably selectable points of respective first and second link arms to bias said swinging movements of the coupler axes.

17. A gymnastic device as defined in claim 11 and including structure rigidly interconnecting the two said first link arms adjacent said one support axis, and structure rigidly interconnecting the two said second link arms adjacent said other support axis.

18. A gymnastic device as defined in claim 11, and including counterweight means mounted on at least one of said link arms in position to balance the weight thereof at least partially with respect to the associated support axis.

References Cited UNITED STATES PATENTS 46,529 2/ 1865 Metzler 272-52 638,033 11/1899 Stirk 2736l 842,635 l/l907 Dodson 27286 2,123,233 7/ 1938 Crawford 272-61 2,668,579 2/1954 Swengel 27252 ANTON O. OECHSLE, Primary Examiner. M. R. PAGE, Assistant Examiner.