US3683514A - Educational and recreational device - Google Patents

Educational and recreational device Download PDF

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Publication number
US3683514A
US3683514A US91395A US3683514DA US3683514A US 3683514 A US3683514 A US 3683514A US 91395 A US91395 A US 91395A US 3683514D A US3683514D A US 3683514DA US 3683514 A US3683514 A US 3683514A
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ball
pedestal
mass
base
horizontal
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US91395A
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James D Hughes
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    • AHUMAN NECESSITIES
    • A63SPORTS; GAMES; AMUSEMENTS
    • A63FCARD, BOARD, OR ROULETTE GAMES; INDOOR GAMES USING SMALL MOVING PLAYING BODIES; VIDEO GAMES; GAMES NOT OTHERWISE PROVIDED FOR
    • A63F7/00Indoor games using small moving playing bodies, e.g. balls, discs or blocks
    • A63F7/22Accessories; Details
    • A63F7/36Constructional details not covered by groups A63F7/24 - A63F7/34, i.e. constructional details of rolling boards, rims or play tables, e.g. frame, game boards, guide tracks
    • A63F7/3622Specially shaped rolling boards for the balls, e.g. ball tracks
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09BEDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
    • G09B23/00Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes
    • G09B23/06Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics
    • G09B23/08Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics
    • G09B23/10Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics of solid bodies

Abstract

This invention relates to an educational and recreational device which, in one preferred embodiment, includes a directional guidance system mounted in a plane substantially perpendicular to the horizontal. The system defines a continuum of directional guide paths leading from a substantially horizontal guide path element, at its upper end, into a descending S curve, then through a first complete loop of a helical coil, and terminating at a desired exit point on a subsequent loop. The tangent to the exit point is selected to any desired angle with the horizontal. The guidance system is adapted to control the direction of motion of a spherical mass in its travel through the system and to place it into a ballistical trajectory after leaving the system. A catcher, positioned in the line of flight of the spherical mass, retrieves the mass at any selected point along the trajectory. In another embodiment the complete loop of the helical coil lies in a plane substantially parallel with the horizontal.

Description

United States Patent Hughes [451 Aug. 15, 1972 [54] EDUCATIONAL AND RECREATIONAL OTHER PUBLICATIONS DEVICE Catalogue Scientific Instruments, Knott Apparatus [72] Inventor: James D. Hughes, Houston, Tex. 1917 106 Welch Scientific Co. Catalog, Oct. 1965, pp. 69 and [73] Assignee: Michael P. Breston, Houston, Tex. 35
a part interest Primary Examiner-Harland S. Skogquist 1 1970 Attorney-Michael-P. Breston 21 App No.: 91,395
ABSTRACT [52] US. Cl. ..35/19 R, 273/101, 46/43 This invention relates to an educational and recrea- [51] Int. Cl. ..G09b 23/06 tional device which, in one preferred embodiment, in- [58] Field of Search .35/19 R, 19 A, 19 B; 46/42, cludes a directional guidance system mounted in a 4 43; 273 9 R, 120 R, 27 127 3 plane substantially perpendicular to the horizontal. The system defines a continuum of directional guide 5 References n paths leading from a substantially horizontal guide l C path element, at its upper end, into a descending S UNITED STATES PATENTS curve, then through a first complete loop of a helical coil, and terminating at a desired exit point on a subl,345,009 6/1920 Jermyn ..46/43 sequent loop The tangent to the exit point is Selected 1,667,123 4/ 1928 Koller ..273/96 R l 826 180 10/1931 Kl 35 19 R to any desired angle with the horizontal. The guidance opsteg system is adapted to control the direction of motion of Brenner a spherical mass i i travel through the System and to 2,999,689 9/1961 rLltWlflCZLlk ..46/43 X place it into a ballistical trajectory after leaving the 3,235,974 2/1966 Hall ..35/l9 R X system. A catcher, positioned i the line of flight of 3,313,544 4/1967 Davis ..273/127 B UX the Spherical mass, retrieves the mass at any selected Blackburn R point along the trajectory In another embodiment the 3,354,559 11/1967 Beck ..35/19 R complete loop of the helical coil lies in a plane substantially parallel with the horizontal.
5 Claims, 4 Drawing Figures Patented Aug. 15, 1972 2 Sheets-Sheet 1 James D. Hughes FIG. 2
I NVEN TOR.
BY Michael P. Breston ATTORNEY Patented Aug. 15, 1972 3,683,514
2 Sheets- Sheet 2 3 v James D. Hughes INVENTOR.
BY Michael R Breston ATTORNEY 1 EDUCATIONAL AND RECREATIONAL DEVICE BACKGROUND OF THE INVENTION Educational devices employing balls to demonstrate Newton's laws of motion are extensively used in laboratories for students. An educational device utilizing swinging balls to demonstrate the law of conservation of momentum is well known. But such devices are usually limited to the demonstration of a single physical law or principle.
It is an object of this invention to demonstrate both dynamically and dramatically the following: the influence of the force of gravity in transforming the potential energy of an elevated body into kinetic energy of motion; the operation of Newton's three laws of motion in the gravitational field; the effect of the centripetal force on a body moving in a circular path; the effect of gravity upon the ballistical trajectory of a launched body; and the dissipation of the kinetic energy of the body upon impact with a target.
It is a further object of this invention to demonstrate, in a dynamic and entertaining fashion, each andall of the above principles in a predetermined sequence, during a single trip of a ball, beginning with its movement from an initial state of rest until its final state of rest on the target. 1
SUMMARY OF THE INVENTION mass is terminated by a target which catches andretains the descending mass.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of one embodiment of the educational and recreational device of the present invention;
FIG. 2 is a top view of the embodiment shown in FIG.
FIG. 3 is a view in perspective of a modification of the catcher assembly shown in FIG. 1; and
FIG. 4 is a view in perspective of another embodiment of this invention.
In the drawings, wherein the same numerals refer to the same or similar parts, the educational and recreational device is generally designated as 10 and includes a directional guidance system 12 which, in use, is fixedly supported by retainer clamps 11 in a plane substantially perpendicular to the horizontal. The support is provided by a base member 14 which can be part of device 10, or which can be provided by any suitable base such as the top of a table or desk. Guidance system 12 extends vertically from base 14 a distance sufficient to provide the necessary amount of potential energy, as will be more fully described subsequently. In the embodiment shown in FIGS. 1 and 2, a vertical member 16 has its bottom end secured to base 14 and its top end fastened to a block 18 adapted to anchor the topmost portion of the guidance system.
System 12 has a convolute form made of a continuum of directional guide paths leading from a sub stantially horizontal path portion 19 into a descending S curve portion 22, and then through a complete loop 24 of a spiral or helix generally designated as 23. From loop 24 the guide path continues in an upward direction until terminated at an exit point 25 whose tangent provides the proper initial angle with the horizontal for the desired ballistical trajectory 26.
Guidance system 12 can be made from various materials such as from plastic tube or from plastic or metallic extruded shapes. Preferably, however, system 12 is made from two spaced parallel rails 30 and 32, each rail being formed of a cylindrical rod which can be solid or hollow. By using two spaced cylindrical rails, the friction is minimal since the points of contact with a rolling ball 34 are limited to two.
Guidance system 12 is adapted to control the direction of motion of the spherical mass or ball 34 which is preferably made from a non-corrosive substance such as stainless steel. For reasons which will become subsequently apparent, it is desired that the sphere be made from a ferrous material. The weight and diameter of mass 34 are selected in relation to the spatial arrangement and dimensions of guidance system 12 so that when ball 34 is set in motion at the upper and beginning portion 19, it will acquire the momentum needed to propel it through system 12 as well as launch it into the ballistical trajectory 26 subsequent to its exit from system 12 at terminal 25.
To catch ball 34 in the line of flight 26, there is provided a target or catcher assembly, generally designated as 40. Target 40 in one embodiment includes an elastic receptacle 42 preferably in the form of an elongated cup having a cylindrical bore 44 whose diameter is substantially equal to or slightly less than the diameter of ball 34. Bore 44 is open at its upper end 45 and closed at its bottom end 46 which serves as a base for attachment of cup 42 to a supporting pedestal 47. Cup 42 can be fixedly or loosely secured to pedestal 47 as by a screw 48. Pedestal 47 allows cup 42 to become properly oriented for receiving the descending ball 34. Pedestal 47 can be fixedly or releasably attached to base 14 or its equivalent.
In FIG. 3 is shown another embodiment of a catcher assembly, generally designated as 50, which includes a receptacle 52 attached to and supported by a pedestal 53 upon, or within the bottom of, which is contained a permanent magnet 54 of channel cross section whose poles 55 and 56 are in or near contact with a ferrous plate 57. Plate 57 is secured to or recessed in base 14. The magnetic attraction between magnet 54 and plate 57 is such that the entire catcher assembly 50 may be moved to any desired location on plate 57 yet hold firmly in relation to base 14 with receptacle 52 being in proper alignment to receive ball 34 at a selected point in its trajectory 26. The permanent magnet 54 may be of a different cross section and of difi'erent material, e.g., rubber or ceramic as long as the magnetic attraction between it and the ferrous plate 57 is sufficient to maintain fixed the entire catcher assembly 50 after it has once been located in proper reference to the guidance system 12 and the trajectory 26.
Catcher assemblies using magnets of other materials and configurations could be used by anyone skilled in the art of magnetics to achieve the same or equivalent results described above.
In operation of the embodiment shown in FIGS. 1 and 2, ball 34 is first positioned on the horizontal portion 19 of guidance system 12. After ball 34 is given a slight initial movement it will accelerate downwardly along S curve 22 to point 24A which marks the common point of tangency of the bottom end of the S curve and the beginning of the first loop 24. From point 24A, ball 34 moves up on loop 24 thereby reducing its speed, but when it reaches point 24B, which is the uppermost point of loop 24, it will still have sufficient momentum to develop the centripetal force necessary for ball 34 to remain in contact with rails 30, 32 and to continue along its helical path. As ball 34 is directed downwardly from point 24B it accelerates until its speed upon reaching the bottom point 24C of loop 24 is substantially the same as it was upon entering the loop at point 24A, neglecting losses due to friction and air resistance.
As ball 34 exits from system 12 at terminal 25 it is propelled into the atmosphere along the ballistical trajectory 26 which is in alignment with the axis of bore 44, thereby allowing receptacle 42 to catch ball 34. As ball 34 enters receptacle 42 its energy will be used up by the work performed in deforming the elastic material defining bore 44 and in compressing the air trapped in bore 44 ahead of the descending ball.
Because of this work is performed over an interval of time, the shock of impact is greatly diminished and the ball comes to rest smoothly. Ball 34 is retained in receptacle 42 by the tension in the stressed elastic material in contact with the ball. The ball can be conveniently extracted from bore 44 by the use of a suitable magnet (not shown). Slight variation in the alignment of the trajectory 26 and the axis of bore 44 can be offset by increasing the angle of acceptance of the upper end 45 of bore 44 and by loosely mounting the bottom end 46 of the catcher 42 on the pedestal 47 to allow for limited swiveling action by the receptacle 42.
Other modifications (not shown) of the catcher assembly could include the use of mechanical linkages composed of say three spacer bars and two clamps. Each clamp would be fashioned to hold and secure a spacer bar of circular cross section at each end. One spacer bar would be fixed to the base in a vertical position. Another spacer bar would have a ball receptacle mounted at one end. By connecting and then manipulating the bars and clamps the receptacle can be positioned to catch the ball at any point in its trajectory.
In FIG. 4 is shown a modified embodiment of the educational device, generally designated as 59. In embodiment 59 the guidance system 60 includes horizontal guide rails 61 and 62 leading into a descending S curve 63. During the descent the guide rails continue to be spaced a uniform distance apart but the plane containing the center lines of the rails is twisted such that, at the lowermost end 64 of the S curve 63, rail 61 is at a lower elevation than rail 62, and such that, on a vertical plane cutting the rails at this point 64, a line drawn through the centers of rails 61, 62 would intersect the horizontal at an angle. Point 64 is also the common point of tangency of the end of the bottom S curve 63 and the beginning of a loop 65 of the helix 66 whose axis is generally perpendicular to base 14.
Helix 66 can be conceptualized as a double-threaded nut of a boIt-and-nut combination in which the space B33222 diitsts adtt3ii%i?8i th%u$%d% parable to the angle at which the rails, defining the helix, are sloping downwardly.
The plane containing the center lines of rails 61, 62 continues to twist at a uniform angular rate as it conforms with the spiral configuration until point 68, which is diametrically opposite to point 64, is reached. At point 68 rail 61 is directly under and parallel with rail 62. Leaving point 68, the plane containing the center lines of rails 61, 62 continues to twist at the same uniform rate while conforming to the spiral path about the helix axis up to point 69. Point 69 marks the completion of loop 65 about the helix axis.
At point 69 rail 61 is still at a lower elevation than rail 62 such that, on a vertical plane cutting both rails, a line drawn through the two rail centers would intersect the horizontal and define an angle the apex of which is directed toward the axis of the helix. Leaving point 69, the plane containing the center lines of rails 61 and 62 continues to twist at the same angular rate but following an upwardly directed arc which is terminated at point 70 on the arc, such that the tangent to the are at that point intersecting with the horizontal will define an angle. This angle is the initial angle of the ballistical trajectory 26 described by the ball 34 when ejected from the guidance system 60 at point 70 with considerable velocity.
It should be remarked that throughout the preceding description the angles referred to are of the optimum degree required to hold the moving ball in contact with the rails throughout its trip through the guidance system 59 in conformity with the physical laws governing bodies at rest and in motion.
What I claim is:
1. A device comprising:
a convolute guidance system mounted on a support base and having two spaced tubular parallel rails leading from an upper entry portion into a descending S curve, then through at least a first complete loop of a helical coil, and terminating at a desired exit point below said entry portion;
said system being adapted to guide a spherical ball from said entry portion to said exit point and to launch said ball in free space along a ballistic trajectory, and
mass-engaging means adapted to retrieve the freefalling mass from its descent trajectory, said massengaging means comprising an elastic cup having a bore whose mouth has a diameter substantially equal to or slightly less than the diameter of said ball.
2. The device of claim 1 wherein said mass-engaging means include a pedestal for supporting said cup.
3. The device of claim 2 wherein said pedestal is fixedly secured to said base.
4. The device of claim 2 wherein said pedestal is movably supported by said base.
5. The device of claim 4 wherein said pedestal and said base include magnetic means to provide magnetic attraction between said pedestal and said base.

Claims (5)

1. A device comprising: a convolute guidance system mounted on a support base and having two spaced tubular parallel rails leading from an upper entry portion into a descending S curve, then through at least a first complete loop of a helical coil, and terminating at a desired exit point below said entry portion; said system being adapted to guide a spherical ball from said entry portion to said exit point and to launch said ball in free space along a ballistic trajectory, and mass-engaging means adapted to retrieve the free-falling mass from its descent trajectory, said mass-engaging means comprising an elastic cup having a bore whose mouth has a diameter substantially equal to or slightly less than the diameter of said ball.
2. The device of claim 1 wherein said mass-engaging means include a pedestal for supporting said cup.
3. The device of claim 2 wherein said pedestal is fixedly secured to said base.
4. The device of claim 2 wherein said pedestal is movably supported by said base.
5. The device of claim 4 wherein said pedestal and said base include magnetic means to provide magnetic attraction between said pedestal and said base.
US91395A 1970-11-20 1970-11-20 Educational and recreational device Expired - Lifetime US3683514A (en)

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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3887184A (en) * 1974-01-18 1975-06-03 Joseph Cavaliere Hand-held and manipulated catch ball game
US4171090A (en) * 1976-12-23 1979-10-16 Rolf Eisenburg Trackway for a trackborne toy
US4319425A (en) * 1980-05-01 1982-03-16 Shine Thomas M Gravity operated track
US4558867A (en) * 1983-12-29 1985-12-17 Mattel, Inc. Toy vehicle trackway set
US4790529A (en) * 1987-01-16 1988-12-13 Pelle Della Ralph Exercise and training device
US5507487A (en) * 1995-03-02 1996-04-16 Capcom Coin Op, Inc. Wire form for pinball skill loop shot
US6102405A (en) * 1997-10-30 2000-08-15 Spikes; Michael D. Toy catapult and game
US20060128255A1 (en) * 2004-10-26 2006-06-15 Mattel, Inc. Toy play set
US7229072B2 (en) 2004-09-30 2007-06-12 Difrancesco Jr Anthony Playing surface for a game and method of using a game playing surface
US20090075558A1 (en) * 2007-09-14 2009-03-19 Mattel, Inc. Toy vehicle track set
US7618302B2 (en) 2004-10-26 2009-11-17 Mattel, Inc. Toy play set
US20110053456A1 (en) * 2007-09-14 2011-03-03 Ostendorff Eric C Toy vehicle track set
US7946903B2 (en) 2006-05-04 2011-05-24 Mattel, Inc. Wheeled toy vehicles and playsets for use therewith
US20150065009A1 (en) * 2013-09-05 2015-03-05 Target Brands, Inc. Activity center toy

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1345009A (en) * 1919-07-07 1920-06-29 Percy V Jermyn Toy
US1667123A (en) * 1925-03-02 1928-04-24 Koller Karl Toy
US1826180A (en) * 1929-05-11 1931-10-06 Paul E Klopsteg Educational apparatus
US1896607A (en) * 1932-09-21 1933-02-07 Brunner Peter Toy
US2999689A (en) * 1959-02-27 1961-09-12 Victor W Litwinczuk Portable table bowling game
US3235974A (en) * 1963-12-30 1966-02-22 Barnes Eng Co Instructional spectrometer
US3313544A (en) * 1964-10-23 1967-04-11 Edward R Davis Golf putting practice device
US3320686A (en) * 1964-12-04 1967-05-23 Walter L Blackburn Ball drop
US3354559A (en) * 1965-08-19 1967-11-28 Bernard O Beck Ballistic pendulum

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1345009A (en) * 1919-07-07 1920-06-29 Percy V Jermyn Toy
US1667123A (en) * 1925-03-02 1928-04-24 Koller Karl Toy
US1826180A (en) * 1929-05-11 1931-10-06 Paul E Klopsteg Educational apparatus
US1896607A (en) * 1932-09-21 1933-02-07 Brunner Peter Toy
US2999689A (en) * 1959-02-27 1961-09-12 Victor W Litwinczuk Portable table bowling game
US3235974A (en) * 1963-12-30 1966-02-22 Barnes Eng Co Instructional spectrometer
US3313544A (en) * 1964-10-23 1967-04-11 Edward R Davis Golf putting practice device
US3320686A (en) * 1964-12-04 1967-05-23 Walter L Blackburn Ball drop
US3354559A (en) * 1965-08-19 1967-11-28 Bernard O Beck Ballistic pendulum

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Catalogue Scientific Instruments, Knott Apparatus Co., Jan. 1917, p. 106 *
Welch Scientific Co. Catalog, Oct. 1965, pp. 69 and 85 *

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3887184A (en) * 1974-01-18 1975-06-03 Joseph Cavaliere Hand-held and manipulated catch ball game
US4171090A (en) * 1976-12-23 1979-10-16 Rolf Eisenburg Trackway for a trackborne toy
US4319425A (en) * 1980-05-01 1982-03-16 Shine Thomas M Gravity operated track
US4558867A (en) * 1983-12-29 1985-12-17 Mattel, Inc. Toy vehicle trackway set
US4790529A (en) * 1987-01-16 1988-12-13 Pelle Della Ralph Exercise and training device
US5507487A (en) * 1995-03-02 1996-04-16 Capcom Coin Op, Inc. Wire form for pinball skill loop shot
US6102405A (en) * 1997-10-30 2000-08-15 Spikes; Michael D. Toy catapult and game
US7229072B2 (en) 2004-09-30 2007-06-12 Difrancesco Jr Anthony Playing surface for a game and method of using a game playing surface
US7527542B2 (en) 2004-10-26 2009-05-05 Mattel, Inc. Toy play set
US20060128255A1 (en) * 2004-10-26 2006-06-15 Mattel, Inc. Toy play set
US7618302B2 (en) 2004-10-26 2009-11-17 Mattel, Inc. Toy play set
US7946903B2 (en) 2006-05-04 2011-05-24 Mattel, Inc. Wheeled toy vehicles and playsets for use therewith
US20110223829A1 (en) * 2006-05-04 2011-09-15 Mattel, Inc. Wheeled toy vehicles and playsets for use therewith
US8465339B2 (en) 2006-05-04 2013-06-18 Mattel, Inc. Wheeled toy vehicles and playsets for use therewith
US9492759B2 (en) 2006-05-04 2016-11-15 Mattel, Inc. Wheeled toy vehicles and playsets for use therewith
US20090075558A1 (en) * 2007-09-14 2009-03-19 Mattel, Inc. Toy vehicle track set
US20110053456A1 (en) * 2007-09-14 2011-03-03 Ostendorff Eric C Toy vehicle track set
US7963821B2 (en) 2007-09-14 2011-06-21 Mattel, Inc. Toy vehicle track set
US8192246B2 (en) 2007-09-14 2012-06-05 Mattel, Inc. Toy vehicle track set
US20150065009A1 (en) * 2013-09-05 2015-03-05 Target Brands, Inc. Activity center toy

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