US3797131A

US3797131A - Kinematics educating

Info

Publication number: US3797131A
Application number: US00255103A
Authority: US
Inventors: J Orfei; J Walters
Original assignee: American Science and Engineering Inc
Current assignee: UNITED STATES TRUST Co
Priority date: 1972-05-19
Filing date: 1972-05-19
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

An adjustable inclined plane is formed with recesses for accommodating a modified hypodermic syringe that may accommodate a stopper in place of the needle assembly. A student may conveniently rapidly advance the plunger to expel the stopper and observe its trajectory as a function of the inclined plane angle. The inclined plane is also formed with a trough for guiding a rolling ball toward a sled that rests of three points, is formed with a recess for accommodating a vial for carrying different weight and receives the rolling ball at its forward end so that the student may observe how the kinetic energy of the rolling ball moves the sled a distance related to the angle of the inclined plane and the weight in the vial.

Description

[ Mar. 19, 1974 KINEMATICS EDUCATING [75] Inventors: John B. Orfei, North Revere; John Walters, Lexington, both of Mass.

[73] Assignee: American Science & Engineering,

Inc., Cambridge, Mass.

[22] Filed: May 19, 1972 21 Appl. No.: 255,103

[ 56] References Cited UNITED STATES PATENTS 10/1956 Schwartz 124/11 A 11/1959 Keefeuul.

8/1971 Bodley; 35/19 R Primary Eraminer-Harland S. Skogquist Attorney, Agent, or Fi'rm--Charles Hieken; Jerry Cohen [5 7 ABSTRACT An adjustable inclined plane is formed with recesses for accommodating a modified hypodermic syringe that may accommodate a stopper in place of the needle assembly. A student may conveniently rapidly advance the plunger to expel the stopper and observe its trajectory as a function of the inclined plane angle. The inclined plane is also formed with a'trough for guiding a rolling ball toward a sled that rests of three points, is formed with a recess for accommodating a vial for carrying different weight and receives the rolling ball at its forward end so that the Student may observe how the. kinetic energy of the rolling ball moves the sled a distance related to the angle of the inclined plane and the weight in the vial.

10 Claims, 5 Drawing Figures PATENTED I IAR 19 I974 SHEET 1 BF 2 PAIENTED m 1 91914 SHEET 2 [IF 2 1 l KINEMATICS EDUCATING BACKGROUND OF THE INVENTION The presentinvention'relates in general to kinematics educating and more particularly concerns novel apparatus and techniques for safely teaching children about physical principles of kinematics with apparatus that is relatively. inexpensive, safe andfun for children to use as they learn. Especially advantageous from the standpoint of economy is the use of the inclined plane according to the invention for multiple functions in teaching about projectile trajectories and converting potential energy into'kinetic energy and then into frictional enery.

It is an important object of this invention to provide improved apparatus and techniques for educatin about kinematics. I v

It is another object of the invention to achieve the preceding object with apparatus that maybe used by small children to educate them in these principles.

It is another object of the invention to achieve one or more of the preceding objectswith apparatus that is relatively easy and inexpensive to fabricate, relatively difficult tomalfunction, safe for use by small children, fun to use and graphically demonstrate principles of kinematic.

SUMMARY 'OF THE INVENTION According to the invention, there is means defining an inclined plane pivoted at a lower end to a supporting base that carries adjustable support means for supporting the inclined plane at selected different angles and means for supporting a modified hypodermic syringe so as to provide additional finger gripping means to facilitate straddling the modified hypodermic syringe with the first and second fingers while using the thumb to actuate the plunger. According to another feature of the invention, the inclined plane means is formed with a trough, preferably marked along its length at equal increments, for guiding a'rolling mass toward'sled means.

Preferably the sled means is a unitary structure that rests on three points..'l"wo of the points are at'the rear and separated by a rear openingthrough whichthe ball enters. The remaining point is at thefront ahead of the front portion of the sled upon which the ball impacts to move the sled forward a distance dependent upon the kinetic energy carried by the rolling ball, which in turn depends upon the angle of the inclined plane and the distance of the .ball alongthe groove at the time it was allowed to roll, and the mass of the sled. Preferably the sled is formed with an opening for accommodating a vial that may contain a number of type weights fora]- tering the effective mass of the sled.

Numerous other features, objects and advantages of the invention will become apparent from the following specification when read in connection with the accompanying drawing in which:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the inclined plane according to the invention when flat;

FIG. 2 is a view of the invention with the inclined plane set at 40 with respect to the horizontal illustrating a rolling ball moving toward the sled according to the invention; I

FIG. 3 is a sectionalview through section 3-3 of the sled of FIG. 2;

FIG. 4 is a view of the invention with the inclined plane supported at 9O with respect to the horizontal for supporting a propeller; and a FIG. 5' is a view of most of the assembly as shown in FIG. 4 from the underside of the incline plane illustrating support structure.

' DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference now to the drawing and more particularly FIG. 1 thereof, there is shown a perspective view of an embodiment of the invention. The adjustable inclined plane 11 is preferably a unitary structure of thermo plastic and accommodates a modified hypodermic syringe 12 in a rounded recess with the stem 13 of the modified hypodermic syringe adjacent to

tabs

14 and 15 backed by recesses such as 16 where a user may place his index and middle finger for straddling modified hypodermic syringe 12 while pressing on plunger 17 rapidly to eject stopper 21 which replaces the needle assembly of a commercially available B-D Plastipak Discardit- 10cc hypodermic syringe,. and launch it on a trajectory largely determined by the angle of inclination of inclined plane 11. Inclined plane 11 is pivotal about the axisdefined by screws such as 22 tightened by wing nuts such as 23, only one of the pair being visible in FIGS. 1 and 2. There is a like screw and wing nut on the other side.

Referring to FIG. 2, there is shown a view of the invention with the inclined planeadjusted at an angle of substantially 40. The inclined plane 11, when horizontal as shown in FIG. 1, embraces supporting base 24 that carries a pair of blocks, one of which 25 is visible in FIG. 2, best seen in FIG. 5. One end of blocks 25 extend out beyond the edge of base 24 for allowing inclined plane 1 l to stand upright and carry bolts 22, typically bolts formed with a tapering square cross section to facilitate pressing the bolts in drilled openings in blocks 25 for rapid assembly while preventing rotation when wing nuts 23 are secured to the threaded ends. Blocks 25 are also formed with openings at the other end for accommodating the ends 26 of U-shaped support 27. Support 27 is arranged so that the corners 28 (FIG. 5) seat in a groove defined bymeans including the faces forming an angle with the large flat upper surfaces of inclined plane 11 corresponding substantially to the number designated on the face, the face having its designation immediately adjacent to it. Thus, in FIG. 2 inclined plane 11 is at an angle of substantially 40 with the plane of support base 24.

Inclined plane 1 l is formed with a tapering trough 31 with linearly displaced markings 1-5 for accommodating a metal ball such as 32 directed to roll toward sled 33, enter it and move sled 33 along for a distance dependent upon the mass of sled 33 and the kinetic energy of ball 32. Sled 33 is preferably of thermoplastic material and has a front support 34 and rear supports 35, one of which is visible in FIG.-2. Sled 33 is also formed with arecess for accommodating vial 36 that may carry different weights for controlling the effective mass of sled 33.

Referring to FIG. 3, there is shown a sectional view through section 3-'3of FIG. 2 with vial 36 removed. The rolling ball may enter the rear of sled 33, strike the front surface 36 and move the sled along surface 37 until the kinetic energy of the rolling ball is dissipated into frictional energy as the sled slides along surface 37.

Referring to FIG. 4, there is shown a view of the invention supported at an angle of 90 with hypodermic syringe 12 carrying a rotatable shaft propeller support 41 rotatably supporting propeller 42 to permit the invention to function as a support for propeller rotating experiments.

Having described the structural arrangement of the invention, it is appropriate to consider some of its uses. Consider first its use in trajectory experiments. First plunger 17 is withdrawn. Then a stopper 21 is placed in the end of modified syringe 12. The child may then adjust the angle of inclined plane 11 in a first experiment, place his first and middle fingers against finger supports 14 and 15 and press plunger 17 rapidly to expel stopper 21. The child may then observe the distance traveled by stopper 21. He may then repeat the experiment at a different angle and note the different distance traveled along the different trajectory. The child can thus observe that the distances traveled by the stopper at 20 and 70 degrees are about the same while maximum travel occurs for the 40 setting.

Turning now to experiments related to conservation of energy the child may position the inclined plane 11 at one of the angles, position sled 33 with its open end at the bottom of trough 31, place a predetermined weight in vial 36, set steel ball 32 beside one of the lines 1-5, release it and observe how far sled 33 travels. He can repeat this experiment for different inclined plane angles, different starting points for ball 32 and different weights in vial 36. He thus learns a number of principles related to action and reaction, conservation of energy and other principles of physics. For example, the higher ball 32 when it starts, the greater its potential energy that is converted into kinetic energy as it leaves trough 31, and the further it pushes sled 33. The greater the weight in vial 36, the greater the frictional force opposing sliding of sled 33, and the less sled 33 travels. A child may thus be taught principles of physics and try them out with this inexpensive apparatus capable of withstanding rugged use by children while minimizing the chance of injury.

There has been described novel apparatus capable of educating and entertaining children and others while being relatively inexpensive and easy to fabricate. It is evident that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features said inclined plane being formed with means at its other end for supporting a modified hypodermic syringe in a recess flanked by upstanding projections for engagement with tabs of a modified hypodermic syringe to be supported therein opposing movement of the modified syringe as the plunger of the modified syringe is depressed and for providing support for fingers flanking the modified syringe when the modified syringe plunger is depressed.

2. Kinematics educating apparatus in accordance with claim 1 wherein'said inclined plane is formed with a trough from said one end to a point below said projections for accommodating a ball to be rolled therealong.

3. Kinematic educating apparatus in accordance with claim 1 wherein said means for adjustably supporting comprises a generally U-shaped element having the ends of its legs pivotally supported at said base intermediate the ends thereof and the intersection of its legs and bight arranged for making engagement in recesses formed in said inclined plane for supporting said inclined plane at predetermined angles relative to said base.

4. Kinematic educating apparatus in accordance with claim 2 wherein said means for adjustably supporting comprises a generally U-shaped element having the ends of its legs pivotally supported at said base intermediate the ends thereof and the intersection of its legs and bight arranged for mating engagement in recesses formed in said inclined plane for supporting said inclined plane at predetermined angles relative to said base.

5. Kinematics educating apparatus in accordance with. claim 3 wherein said recesses are defined by means including sloping faces that make an angle with said base when said inclined plane is'parallel to said base corresponding substantially to the angle said inclined plane makes with said base when said support element resides in the recess defined by a respective sloping face.

6. Kinematics educating apparatus in accordance with claim 4 wherein said recesses are defined by means including sloping faces that make an angle with said base when said inclined plane is parallel to said base corresponding substantially to the angle said inclined plane makes with said base when said support element resides in the recess defined by a respective sloping face. 7

7. Kinematics apparatus in accordance with claim 2 and further comprising sled means open at the bottom and rear and closed at the top and front and resting on three points with one point at the front and the other two at the rear embracing the rear opening.

8. Kinematics apparatus in accordance with claim 7 wherein said sled means is formed with a recess for accommodating a vial that may carry weights.

9. Kinematics apparatus in accordance with claim 8 and further comprising said vial in said recess.

10. Kinematics educating apparatus in accordance with claim 1 and further comprising,

said modified hypodermic syringe seated in said recess flanked by said upstanding projections.

Claims

1. Kinematics educating apparatus comprising, means defining a base, means defining an inclined plane, means for pivotally attaching one end of said inclined plane to one end of said base, means for adjustably supporting said inclined plane at a number of different angles relative to said base, said inclined plane being formed with means at its other end for supporting a modified hypodermic syringe in a recess flanked by upstanding projections for engagement with tabs of a modified hypodermic syringe to be supported therein opposing movement of the modified syringe as the plunger of the modified syringe is depressed and for providing support for fingers flanking the modified syringe when the modified syringe plunger is depressed.

2. Kinematics educating apparatus in accordance with claim 1 wherein said inclined plane is formed with a trough from said one end to a point below said projections for accommodating a ball to be rolled therealong.

5. Kinematics educating apparatus in accordance with claim 3 wherein said recesses are defined by means including sloping faces that make an angle with said base when said inclined plane is parallel to said base corresponding substantially to the angle said inclined plane makes with said base when said support element resides in the recess defined by a respective sloping face.

6. Kinematics educating apparatus in accordance with claim 4 wherein said recesses are defined by means including sloping faces that make an angle with said base when said inclined plane is parallel to said base corresponding substantially to the angle said inclined plane makes with said base when said support element resides in the recess defined by a respective sloping face.

10. Kinematics educating apparatus in accordance with claim 1 and further comprising, said modified hypodermic syringe seated in said recess flanked by said upstanding projections.