US2911063A

US2911063A - Automatic jump rope

Info

Publication number: US2911063A
Application number: US736746A
Authority: US
Inventors: Byron L Wolfson
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-05-21
Filing date: 1958-05-21
Publication date: 1959-11-03
Anticipated expiration: 1976-11-03

Description

Nov. 3, 1959 B. L. WOLFSON 2,911,063

AUTOMATIC JUMP ROPE Filed May 21, 1958 I 2 Sheets-Sheet 1 INVENTOR Ema/v L. WoL Fs0/v y M W) ATTORNEY Noy. 3, 1959 B. L. WOLFSON 2,911,063

AUTOMATIC JUMP ROPE Filed May 21, 1958 2 Sheets-Sheet 2 Ema/v L. W01. FSON BY v %M ATTORNEY United States Patent .-The present invention relates generally to mechanisms for rotatin'g elongated flexible material and more particularly to an .apparatus for rotating one end of a jump rope, the other end of which is secured to a suitable support.

Briefly describing the general concept ofthe invention,

an. elongated shaft is rotatably supported in a generally.

horizontal position by two bearing structures attached to a. stationary frame. Disposed on one end .of-the shaft, externally of theframe, is a weighted arm which is generally perpendicular to the shaft. A rope'is adapted to bezattached to the end of this arm and a source of motor power is secured to the shaft to produce rotation thereof. The weighted arm is employed to reduce the angular velocity of the arm on its upward movement, thereby to simulate the movement of a jump rope when it ispropelled by-human means.

The-apparatus forrotating the shaft may take. several forms. and in onespecificembodiment of the invention comprises two spiral springs disposed about the shaft and each having one end secured to the shaft and the other end secured. to the frame. The convolutions of the springs are oppositely directed so that when one spring is wound,

onan end of the shaft, opposite to the end to which the arm-isattached, and initially the crank is operated so that one of the-spiral springs is wound and the other is unwound. Upon releasing the handle, the shaft rotates in one direction, for example for twenty turns, and then rotates backin the opposite direction for approximately nineteen turns. The oscillatory movement of thelshaft therefore conforms to that of a damped oscillatory body and themechanism may continue to oscillate back and forth, for aconsiderable length of time, for example, fifteen to twenty minutes.

- Such an apparatus may be employed by a child who wishes; to jump rope and does not have a playmate availableufor. rotating the rope. The rope has one end attachedto a suitable stationary object and the other end attached to the-end of the weighted arm and the mechanism of the invention is displaced by a suitablev distance from the stationary member so as to provide a loop which just barelydrags the, ground. The apparatus is then cranked and released, .providing a continuing. motion. Smaller children may not wish to have a rope which is continually rotating in the same direction, but may. wish merely-to have a rope which oscillates to say. 180 at a relatively slow pace, so that a child may jump each time the rope passes in either direction under the child. The apparatus of the present-invention may be readilymodified, .to provide either effect, by either of two arrangements. In a first arrangement a straight leaf spring is secured to the shaft and suitable stops are secured to the frame tointercept the free end of the leaf spring at spaced points about its path of rotation. The apparatus maybe initially-cranked so that the end of. the leaf spring engagesoireof the stops and is tensioned thereby, and their the apparatusis released. By suitably choosing the ice natural period of oscillation of the weighted arm and of the spring,=theoscillations of the arm maybe sustained for a-considerable period of time. In a modification of this latter embodiment of the invention, two oppositely directed spiral springs may be employed in conjunction withthe leafspring in'order to provide a sustained spring force on the shaft in the interval between movement of the free end of the leaf spring between the stops.

It is, accordingly, a broad object of the present invention to provide a mechanism for rotating a jump rope which will simulate the motion of a jump rope when propelled by human means.

It is another object of the present invention to provide a mechanism for rotating a jump rope which produces sustained oscillation of the rope over a relatively long period of time.

It is yet another object of the present invention to provide a mechanism for rotating a jump rope which is spring actuated and which may-rotate the rope first in one direction and then in another direction for a sustained period of time.

' wherein;

Figure 1 is a perspective view of one embodiment of the present invention;

Figure 2 is a cross-sectional view of a side elevation of the first embodiment of the apparatus of the present invention;

the other onezis unwound. A crank handle is disposed Figure 3' is a detailed view of the spring motor of the first embodiment of the apparatus of the invention;

Figure 4 is a detailed view of the method of connectirig the motor springs to the frame of the first embodiment of the invention;

Figure 5 is a second detailed view of the spring motor of the first embodiment of the invention; 1

Figure 6 is a detailed view of the spring motor of a second embodiment of the invention;

Figures 7 and 8 are modifications of the stand structure of theapparatus of the present invention;

Figure 9 is an illustration of a modification of the leg structure of the present invention; and

Figure 10 is a top view of Figure 6.

Referring specifically to Figure 1 of the accompanying drawings, there is provided a frame, generally designated by the reference numeral 1, comprising a first hollow, inverted U-shape member 2 and a second hollow,

inverted U-shape member 3, spaced from and disposed parallel to the first. The

U-shape frames

2 and 3 are interconnected by a bar 4 which is secured to and disposed perpendicularly of the

frame members

2 and 3. Disposed within each of the hollow legs of the U-shape member 2 is a tubular leg 6 which is vertically adjustbe readily adjusted in order to conform to the height of 2: ha -1. t s a ad la r-sen. the.

the child who is employing the structure.

Disposed between the legs of the U-shape member 2 is a hub 11 which is supported between the legsof the member 2 by means ofa plurality of radially extending legs of the U-shape frame 3 and supported therebetween by a plurality of radially extending spokes or bars 14. The hubs 11 and 13 are axially aligned and are adapted to supportaaerank-shaft 1-6 of a crank generall-ydesig nated by the reference numeral 17 and havinga, crank handle 18.. {I'hecrank handle 18 is gdisposed out-wa-rdly of the framemernher 3,.whi-le the crank shaft 16 extends through the hub 11 and forwardly of the frame member 2. An adjustable collar 19 is disposed about the crank shaft 16 and is normally maintained in engagement with the hub 17 so as. to prevent end motion of the crank shaft 16.

Rigidl-y secured to the shaft 16 adjacent the hub 11 g is a wheel 21 which serves as a partial guide for two

spiral springs

22 and 23. The spiral springs. 22 and 23. are disposed about the shaft 16, andhave one end 24 of the spring 23 as viewed in Figure 3 secured to the shaft 16. Theotherend of the spring 23, which'is designated (by the reference numeral 26, is secured to a U-shaped retainer 27 .disposed on the shaft '4 while the corresponding end of the spiral spring '22 is secured to a U-shaped member 28 disposed on a surface of the bar 4. The ends of the spring areformed generally into loops 29 so that they curve about the U-shaped retaining members .and are thereby secured thereto. The springs ,22 :and 23 are disposed n opposite sides of the wheel 21 in close proximity thereto so that their adjacent edges are guided by the wheel; If necessary, wheels or cross members may be disposed on the other sides. of the

springs

22 and 23 to provide further guide means therefor. The convolutions of the

springs

22 and 23 are oppositely directed, so that when one of the springs is wound the other spring is unwound. Winding of one of the springs and unwinding of the other is effected by, rotating the crank handle 18 in a given direction. When the handle is released the wound spring unwinds while the unwound spring winds until a balance of forces is effected, .at which time the spring which was originally unwound winds, and vice versa. At this time the direction of rotation of the shaft 16 is reversed and this process continues all of the initial energy stored in the originally wound springs is dissipated.

Secured to .the end of the .shaft 16 remote from the I crank handle 18 is a hollow arm.. 31 which extends substantially at right angles to the shaft 16. The hollow arm 3'1 is adapted to support a rod 32 which is disposed within the hollow arm 31 and is s'lidable with respect thereto. Therefore, the total length of the transverse arm may be adjusted and the position of the arm 32 may be maintained by tightening athumb screw 33. The arm 32 is provided with a weight 34 and terminates at itsend in a loop 36 to which a jump rope 37 may be tied. The purpose of the weighting of the arm 34 is two-fold. ;In a first instance, it serves to increase the moment of inertia of the transverse arm to which the rope 37 is attached, and therefore by adjusting the total length of the arm comprising the memberslfll and 32, therate at which the rope is rotated maybe controlled. The other put pose for the weight 34 is to reduce the angular velocity of the-rope on upward movement of the arms 3-l-32 Since the arms 3132 is weighted and therefore will produce a considerable downward force while moving.

from its uppermost position to its lowermost position, the end the frame 1 constitutingv the 'U-shape member '3 and legs 8 must beappropriately weighted to prevent the 4 legs 8 from being pulled oif the ground by the downward thrust of the arm at the opposite end.

In a second embodiment of the present invention, illustrated in Figures 6 and 10 of the accompanying drawings, a long flexible leaf spring 38 is secured to the wheel 21 and extends radially therefrom. The spring 38 is positioned about the circumference of the wheel 21 such that it is disposed immediately under the center bar 4 when the

springs

22 and 23 are at rest position A first horizontal stop pin 39 extends from one of the legs of the U-shape member 2 toward the U-shape member 3 a sufficient distance to intercept the leaf .spring 38 when .it is rotated sufficiently to come into the plane of the member 39. Similarly, a horizontally extending stop member 41 extends from the other leg of the frame 2 toward the frame member '3 and is adapted to intercept the spring 38 upon its rotation into the plane of the member 41. In this embodiment of the invention, the apparatus is intended to oscillate the rope 37 through an:' angle .less than 360, and as illustrated in Figure 6 less than 180. In operation the crank18 is rotated until the spring 38 comes into contact with one of the stop members 39 and is ten sioned againstthe stop. Upon releasing the crankhandle during which oscillations may be sustained. 'Thesprings- 22 and 23 employed in this embodiment, although identical in basic structure with those employed in the first em bodiment of the invention, difler in their lengths, so

' they are appreciably tensioned by a rotation of the-shaft 16 through only 90", whereas 'those employed in the first embodiment, illustrated .in Figures 1 through 5, are appreciably tensioned only upon the. shaft 16 being rotated through a large number of turns. The oscillations of the mechanism illustrated in Figure-.6 are sustained-only if the. natural frequency of the arms 31--32 is approximately equal to the natural frequency of the spring .18 and also .of the

springs

22 and 23, if employed. Referring: now to Figure 7 of .the accompanyingzdrawings, there is illustrated another species oftheframe which may be employed to support the: apparatusof the pres ent invention. provided with an inverted V-shaped 'member 42. -"I'-he inverted V-shape member 42 includes hollow legs which are adapted to receive, internally thereof, extensible-legs increase the stability of the frame.

43 which may be secured in a predetermined position by thumb screws 44. The legs 43 in this embodiment-of the invention may terminate in flat disc-like feet 46, to The frame is further provided with a horizontal cross member 47 which extends perpendicular .to the plane of the member 42 and. is secured to. the apex thereof. The member 47 is secured at its end remote from the frame 42 to a hollowvertical leg 48, which bisects the legs of the f-rame42. The. hollow leg 48 is adapted to receive a further leg 49 in telescoping relationship therewith and the leg 49 may be secured in .a given position by a thumb screw '51. The leg 49 also terminates in a fiat disc-like 52 to increase stability of mechanism. A first hub 53" for a crank shaft to be employed with the present vention is disposed within the hollow leg 53, while aseo. 0nd hub 54 is supported on radial spokes 56 between tne. legs of .the V-shaped frame member 42.

Referring specifically to Figure .8 of the accompany. ing drawings, there-is illustrated another form of frame.

member Whichmay be ployed w th th spl f i the invention. The frame illustrated in Figure scam- In this figure one end of the frame is The inverted V-shaped

members

57 and 58 are of the frame. The invention is not limited to any specific form of adjustable leg, and Figure 9 illustrates another form of adjustable leg which may be employed. The leg of the frame which is illustrated in Figure 9, and designated by the reference numeral 63, may be formed from a solid member and is provided with two hollow

U-shaped members

64 and 66 displaced axially along the member 63. An adjustable rod-like leg 67 is adapted to be inserted in the hollow

U-shaped members

64 and 66 and is held against the leg 63 by means of a thumb screw 68.

The apparatus of the present invention is intended to be employed by children and therefore some danger may arise from the fact that when one of the springs, as 22 and 23, is under tension as a result of the winding action provided by the crank handle 18, release of the handle will generate rapid rotation thereof, and it may strike the operator. In order to eliminate this possibility, a suitable handle structure, illustrated in Figure 2, may be employed. Specifically, the handle 18 is connected to the crank shaft 16 by means of a web member 69. The end of the web member 69 remote from the handle 18' terminates in a short stud 71 disposed perpendicular to the member 69 and directed oppositely from the handle 18. The end of the stud 71 terminates a multi-sided element 72, which is specifically illustrated as a foursided member, for the sake of example. The end of the shaft 16 adjacent the hub 13 has a hollow four-sided aperture 73 in which the multi-sided member 72 may be seated. The handle is supported on a rod 74 which extends into an axial recess 76 in the rod 16. Disposed about the rod 74 is a spring, which biases the member 72 outwardly of the aperture 73 so that normally the member 72 does not engage the sides of the recess. As a result the handle 18 may be rotated without rotating the shaft 16. When it is desired to rotate the shaft 16 by the handle 18 the handle is pressed toward the shaft 16 so that the multi-sided member 72 is seated in the aperture 73. The shaft 16 may then be rotated and when it is wished to release the rod 16 the handle 18 is re leased, the spring 76 ejects the member 72 and the rod rotates without producing rotation of the handle.

While I have described and illustrated two specific embodiments of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

What I claim is:

1. A mechanism for rotating a length of flexible material comprising a relatively long shaft, spaced bearings for rotatably supporting said shaft in a generally horizontal position, a frame for supporting said bearings, a pair of spiral springs disposed about said shaft with each having one end secured to said shaft and the other end secured to said frame, said spiral springs having their convolutions directed in opposite directions from one another, an arm secured to an end of said shaft, said arm being disposed generally perpendicularly to said shaft, said arm being sufficiently heavy with respect to said springs to reduce materially the velocity of said arm upon upward movement thereof, and a handle for initially rotating said shaft so as to wind one of said springs.

2. A mechanism for rotating a length of flexible material comprising a relatively long shaft, spaced bearings for rotatably supporting" said shaft in a' generally horizontal position, a frame for supporting said bearings, a source of rotary power'for rotatingsaidshaft, an secured is an end of said shaft, said beingl disposed generally perpendicular to said shaft, said arm being suficiently heavy with respect to the power capability of'sai'd source of rotary power to, reduce materially the, velocity of said arm upon upward movement thereof. I, 3; Afmechanism. for rotating a length of flexible mar terial comprising a relatively .long shaft, spaced bearings for rotatably supporting said shaft iu'a'geneiallyhorizontal position, a frame for supporting said bearings, a pair of spiral springs disposed about said shaft with each having one end secured to said shaft and the other end secured to said frame, said spiral springs having their convolutions directed in opposite directions from one another, an arm secured to an end of said shaft, said arm being disposed generally perpendicular to said shaft, said arm having a weight adjustably secured thereto, said weight being sufficiently heavy with respect to said springs to reduce materially the velocity of said arm upon upward movement thereof, a handle for initially rotating said shaft so as to wind one of said springs.

4. A mechanism for rotating a length of flexible material comprising a relatively long shaft, spaced bearings for rotatably supporting said shaft in a generally horizontal position, a frame for supporting said bearings, spring means having one end secured to said shaft and the other end engageable with said frame, a handle for rotating said shaft to displace said one end of said spring means relative to said other end thereby to'tension said spring means, an arm secured to an end of said shaft, said arm being disposed generally perpendicular to said shaft, said arm being sufiiciently heavy withrespect to said springs to reduce materially the velocity of said arm upon upward movement thereof.

5. A mechanism for rotating a length of flexible material comprising a relatively long shaft, spaced bearings for rotatably supporting said shaft in a generally horizontal position, a frame for supporting said bearings, a flat spring having one end secured to said shaft and the other end free, a pair of stop members secured to said frame and each positioned to intercept said spring adjacent its free end, said stops being disposed at predetermined spaced locations about the path of movement of the free end of said spring, an arm secured to an end of said shaft, said arm being disposed generally perpendicular to said shaft, said arm being sufiiciently heavy with respect to said springs to reduce materially the velocity of said arm upon upward movement thereof, and a handle for initially rotating said shaft so as to bring said spring into contact with one of said stops and thereby tensioning said spring.

6. The combination in accordance with claim 5, further comprising a pair of spiral springs disposed about said shaft, each spring having one end secured to said shaft and the other end secured to said frame, said spiral springs having their convolutions directed in opposite directions to the other.

7. A mechanism for rotating a length of flexible material comp-rising a relatively long shaft, spaced bearings for rotatably supporting said shaft in a generally horizontal position, a frame for supporting said bearings, a pair of spiral springs disposed about said shaft with each having one end secured to said shaft and the other end secured to said frame, said spiral springs having their convolutions directed in opposite directions from one another, an arm secured to an end of said shaft, said arm being disposed generally perpendicularly to said shaft, and a handle for initially rotating said shaft so as to wind one of said springs.

8. A mechanism for rotating a length of flexible material comprising a relatively long shaft, spaced bearings for rotatably supporting said shaft in a generally horizontal a '7 r o position, ,a frame for. supporting s'a'id'bearings, a flat spring References Cited int-he file of thisv patent having." one end secured to. said shaft. and the other end UNITED STATES PATENTS free, a pair of st'op'menfl'aers secured to said frame and Y each positioned ,to' intercept said spring adjacent its free 5 3 Fomelius 8, 1935 end, said stops being, disposed at predetermined spaced 5 $833,534 e May 6,1958 locations about the path of movement of the flee end FOREIGN PATENTS of said spring, an .arm' secured to an end of said shaft, said arm 'being disposed generally perpendicular to said shaft, ,and .a handle for i'nitia'fly rotating said shaft so as p a to'jbring saidfspring into contact with one of said stops 0 and thereby tensioriing .said 'sprin g.

408,300 France Ian. 20, 1910