US 3883136 A
An automatic swing structure which is actuated by repelling magnetic fields periodically established by an electric circuit including a stationary electro-magnet and a movable permanent magnet mounted to the swing which moves through the magnetic field of the stationary electro-magnet with each oscillation of the swing.
Description (OCR text may contain errors)
United States Patent 1191 Kim May 13, 1975 54] AUTOMATIC SWING OPERATED BY 1,966,686 7/1934 Russ 46/235 2,377,175 5/1945 Peer 46/235 ELECTRICITY 2,583,741 1/1952 Kile! 46/235 Young Ho Kim, 1 l64-2, Choryang-dong, Dong-ku, Busan, South Korea Filed: May 18, 1973 Appl. No.: 361,541
Foreign Application Priority Data July 10, 1972 South Korea 4381/72 US. (:1. 272/86; 46/235; 46/238 1111. c1. A63g 9/16 Field Of Search 272/85, 86, 87; 297/273,
References Cited UNITED STATES PATENTS 12/1900 Hayes 272/85 Primary Examiner-Richard C. Pinkham Assistant Examiner-T. Brown Attorney, Agent, or FirmMillen, Raptes 8L White  ABSTRACT An automatic swing structure which is actuated by repelling magnetic fields periodically established by an electric circuit including a stationary electro-magnet and a movable permanent magnet mounted to the swing which moves through the magnetic field of the stationary electro-magnet with each oscillation of the swmg.
1 Claim, 5 Drawing Figures PATENTED HAY I 3 i875 SHEET 2 BF 2 AUTOMATIC SWING OPERATED BY ELECTRICITY BACKGROUND OF THE INVENTION 7 movement thereof. It is an object of this invention to eliminate such inconvenience and to permit the occupant of the swing to enjoy automatic movement of the swing by electrical operation.
SUMMARY OF THE INVENTION According to this invention, a swing arm on which a swing seat is mounted is pivotally connected at its upper end to the upper bar of a supporting frame for the swing. A permanent magnet is mounted to the bottom of the swing arm, and a control box containing stationary electro-magnet having the same polarity as the permanent magnet is mounted to the lower supporting body of the swing frame. To induce movements of the swing arm caused by the repelling force produced by the coaction of similar magnetic poles, the electromagnetic core is positioned on the lower supporting body of the swing frame directly below the path of the permanent magnet as it oscillates with the swing arm. As a result of the repelling force by the same polarity of the two magnets in motion relative to each other, the swing oscillates automatically. preferably, a switching mechanism is provided for energizing the electromagnet which is actuated by the permanent magnet when positioned proximate the electro-magnet.
Specifically, the swing in this invention is characterized by comprising a construction which not only uti lizes the magnetic action between a permanent magnet and an electro-magnet to effect swing movement, but also that the magnetic action inducing the swing movement can be accomplished by a simple magnetic operation.
BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the invention will become manifest to those skilled in the art from reading the following detailed description of a preferred embodiment of the invention when considered in the light of the accompanying claims in which:
FIG. 1 is a perspective view ofa swing embodying the features of the invention with portions partially cut away to clearly illustrate the structure;
FIG. 2 is a side elevational sectional view of the swing illustrated in FIG. 1, showing three positions of the swing arm;
FIG. 3 is an enlarged perspective view of the control box installed-on the lower supporting body of the swing illustrated in FIGS. 1 and 2;
FIG. 4 is an enlarged fragmentary sectional view taken along line A-A of FIG. 2; and
FIG. 5 is a circuit diagram of the electrical network of the system illustrated in FIG. 1 thru 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT According to this invention, as illustrated in the drawings, both'of the free ends of a U-shaped swing arm 4 are swingably fastened by hooks 3 to the upper horizontally disposed bar of a frame 1. The swing arm 4 has a body support 5 having a back rest portion which adjusts to various positions relative to the seat portion thereof. A foot rest 6 is mounted on the swing arm 4 below the body support 5. A box 8 containing a permanent bar magnet 7 is affixed to the bottom of the swing arm 4 by suitable threaded fasteners 9. A lower supporting structure 2 supports the lower horizontally disposed bar of the frame 1.
A control box 10 is secured to the supporting structure 2 and contains an electro-magnet having a coil 11 and an associated core 12 as clearly illustrated in FIG. 3. When the coilll is energized by the circuit illustrated in FIG. 5, the core 12 is magnetized in a fashion such that the upper pole thereof is of the same polarity as the lower pole of a permanent magnet 7 attached to the bottom of the swing arm 4. Normally open switch contacts 13 and 14 are installed adjacent the electromagnet in the control box 10. Upon closing, the switch contacts 13 and 14 supply electrical energy to the electro-magnet to magnetize the core 12. Mounted on the switch contact 14 is a small permanent magnet 15 whose polarity at its upper end is opposite to the lower end of the permanent magnet 7, which causes the contact 14 to move upwardly into contact with the contact 13, when the permanent magnet 7 enters the magnetic field of the permanent magnet 15.
According to the present invention, as illustrated in FIG. 5, the electrical circuit is coupled to a source of alternating current by a plug 16 having two conductors 17 and 18 extending therefrom. The conductor 17 is coupled to a rectifier 19 through the switch contacts 13 and 14 by a conductor 20. The output of the rectifier 19 is connected to a switch 23 through conductors 21 and 22.
A condenser 24 is connected across the output of the rectifier 19 between conductors 21 and 22. Switch 23 is connected to make selective contact with a terminal 25 linked with the inductance coil 1 l or with a terminal 26 linked to the resistance 27 in series with the coil 11.
In operation, the swing embodying the features of the invention is utilized by initially placing an infant in the seat 5. The plug 16 is inserted into an electric socket and the switch 23 is in contact with the terminal 25. In such case, the switch contact 14 moves upwardly to contact the switch contact 13 by magnetic attraction between the small permanent magnets 15 affixed to the switch contact 14 and the permanent magnet 7 affixed to the bottom of the swing arm 4. When electrical contact is made between the switch contacts 13 and 14, the coil 1 1 is energized by the direct current output of the rectifier l9 and the magnetic core 12 maintains the same polarity as the polarity of the permanent magnet 7 affixed to the swing arm 4. Therefore, by the repulsive force of these two magnets, the swing arm 4 is caused to move toward one of the directions illustrated in phantom lines in FIG. 2.
When the swing arm 4 moves through a certain distance, the permanent magnet 7 breaks away from the magnetic field of the small magnet 15. Thus, the switch contact 14 is allowed to return to its normally open position breaking electrical contact with the contact 13 and the supply of electrical energy to the coil 11 is ceased. Accordingly, the eIectro-magnetic core 12 simultaneously becomes demagnetized.
When the swing arm 4 returns to the original position, the permanent magnet and the electromagnetic core 11 is magnetized by reestablishing electrical contact between the contacts 13 and 14. In this case, the swing arm 4 moves to another position by inertia and the movement of the swing arm 4 continues to oscillate between the two positions illustrated by the phantom lines in FIG. 1.
When the switch 23 is moved to make contact with the terminal 26 in lieu of the terminal 25, the amplitude of oscillation of the swing arm 4 is somewhat reduced because the current supplied to the coil 11 is reduced by the resistance of the resistor 27.
As mentioned above, the swing of the invention can operate automatically without the need of an operator and will continue to effect a movement of regular distance to the swing arm 4 giving satisfaction and pleasure to the infant in the seat 5. Operation of the swing can be initiated manually.
It will be apparent that the respective positions of permanent magnet 7 and the electro-magnet can be reversed.
From the forgoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the inventnion to adapt it to various usages and conditions.
1. An automatic swing comprising:
a main frame;
a swing arm pivotally connected at its upper end to said main frame;
a first permanent magnet affixed to the bottom end of said swing arm;
an electro-magnet affixed to the bottom of said main frame immediately below the path of the permanent magnet; and
electrical circuit means isolated from said main frame and said swing arm for selectively energizing said electro-magnet and effecting an automatic oscillatory movement of aid swing arm by coaction between the magnetic field of said permanent magnet afffixed to said swing arm and the magnetic field of said electro-magnet, wherein said electrical circuit means includes:
a normally open switch;
a second permanent magnet affixed to said normally open switch and coacting with said first permanent magnet to close said switch only while said first permanent magnet is positioned proximate said electro-magnet,
electrical resistance means; and
switch means for selectively coupling said resistance means into and out of said circuit for varying the amplitude of oscillation of said swing arm.