US2488423A - Apparatus for illustrating economic laws - Google Patents

Description

Nov. 15, 1949 J. D. MooNEY APPARATUS FOR ILLUSTRATING ECONOMIC LAWS Original Filed May 22, 1947 4 Sheets-Sheet l Nov. 15, 1949 J. D, MOONEYv 2,488,423

.APPARATUS FOR ILLUSTRATING ECONOMIC LAWSl Original Filed May 22, 1947 4 Sheets-Sheet 2 l 6g; i L INVENTOR.

Nov. 15, 1949 J. D. MooNEY 2,488,423

I APPARATUS FOR ILLUSTRATING ECONOMIC LAWS Original Filed May 22, 1947 4 Sheets-Sheet 5 Pme.;

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Nov. l5, 1949 J. D. MOONEY APPARATUS FOR ILLUSTRATING ECONOMIC LAWS Original Filed May 22, 1947 4 Sheets-Shes?I 4 "lllllh A INVENToR. f//zmj o/Mg Patented Nov. 15, 1949 UNITED STATES PATENT OFFICE James D. yMooney, Oyster Bay, N. Y.

Original application May 22, 1947, Serial No. 749,645. Divided and this application October 8, 1948, Serial No. 53,561

2 Claims.

This invention relates to improvements in apparatus designed to illustrate the laws of economics by physical analogies. Apparatus of this typev were set forth in my U. S. Letters Patent Nos. 1,989,378 and 2,281,368. The object of the present invention is to provide improved means for giving the mind physical pictures to aid in grasping abstract conceptions. This application is a division of application Serial No. 749,645, filed May 22, 1947, now Patent No. 2,485,540 of Oct. 10, 1949.

While in my earlier inventions the effect of various economic factors on the price of commodities was indicated by a pointer passing over a scale, what the changes in price as indicated by the position of the pointer really meant economically speaking was left to the demonstrator. It is a help in studying the operation of these devices to have a series of appropriate legends explaining what is happening. By means of a suitable signal light system the particular legend applicable at each instant is indicated. These legends, being visble continuously while the machine is operating, avoid the necessity of having to remember just what the demonstrator said a few minutes earlier.

The subject chosen for illustration in the present invention is the series of interrelated forces and reactions pertaining to supply, demand and price; the all-embracing naine commonly used for these relations being The Law of Supply and Demand. Included in this so-called law are the facts that:

(1) Prices depend upon supply and demand. They tend to rise if supply decreases or if demand increases. Conversely, they tend to fall if supply increases and demand decreases.

(2) Supply and demand are aiected by prices. High prices tend to cause an increase in supply and a decrease in demand. Conversely, low prices tend to cause a decrease in supply and an increase in demand.

The rise and fall of price are represented by the rising and falling motion of a float which supports the dead weight of an Inventory receptacle. When a large amount of liquid fills the receptacle, representing large inventories of goods, the weight in the receptacle causes the float to sink deeply in its supporting fluid, this action typifying falling prices. Conversely, when the Inventory receptacle is nearly empty, representing a condition of scarcity of goods available for sale, the float supporting the receptacle rises, typifying rising prices.

Movements of the float operate selectively a group of switches connected to various indicator or signal lamps which serve to direct the observers attention to one or other of a series of legends describing the nature of the action taking place.

Such signal-lamp system also includes means for indicating not only that the iioat is moving, but also its direction of movement. For this purpose, an inertia-operated switch mechanism is used which will close the circuit alternatively through one or other of a pair of signal lights according to the direction of movement. Also such circuit is closed only when the rate of movement ci the iioat exceeds a predetermined value. The mechanism opens such circuit when the rate of movement becomes less than such predetermined value.

One suitable form of construction is illustrated, by way of example, in the accompanying drawings, wherein:

Fig. l is a front elevation of the apparatus as a whole;

Fig. 2 is a diagrammatic front elevation of the apparatus showing the liquid circulation means;

Fig. 3 shows the wiring diagram for the valveactuating motors;

Fig. 4 is a more or less diagrammatic View of the float, Inventory receptacle, and the mechanism and switches operated by movements of the former;

Fig. 5 is a plan View of the push button panel;

Fig. 6 is a diagram showing the ranges over which the various motor-controlling switches are operative;

Fig. 7 is a detail view on an enlarged scale of part of the mechanism shown in Fig. 4; and

Fig. 8 is a section on the line 8 8 of Fig. 4.

The apparatus illustrated comprises a cabinet IB having a wall II extending upwardly from its rear side. This cabinet performs a dual function; iirst it acts as a support for parts of the apparatus, such as the Stable Money tank I2 and the Demand distributor I3, and second it serves as a housing for the Water reservoir I4, pump I5 and motor I6.

The liquid circulating system is shown in Fig.

2. Water is forced by pump I5 through pipe I'I,k

'valve I8 to a header I9 on the Supply shelf 20. From the header I9 is a series of outlets 24, three as shown. Adjacent to the iirst of these, as shown in Fig. 1, are miniature gures and models representing the delivery of barrels and packing cases containing manufactured goods. Over the second is the representation of an oil derrick as symbolic of natural mineral products. Adjacent the third is a farm wagon to indicate the supply of wheat, cotton and other farm products.

Water discharged from these outlets iiows forwardly over the shelf and down its front where an inclined 'trough 25 collects the water 'from all three outlets and discharges it as a single stream through a spout 26. Beneath this spout is an Inventories receptacle 21 of glass or other transparent material mounted on .top Yof the float 28 .in the tank l2. From the bottom of receptacle 21 extends a pipe 26a for discharging water into the Demand distributor I3.

The Demand distributor consists of a cylinder 33 from which lead a series of outlet pipes 34. These pipes discharge into a series of downcasts 35, the lower ends 'of which are above the level of the water in the reservoir i4. Around the downcasts .is the representation of a retail store to simulate the distribution of diierent'classes of goods to the consuming public.

The pump i is of the centrifugal type as that type delivers water at a constant pressure rather than at a constant volume. With a pump having these characteristics, the volume of water delivered thereby is roughly proportional to the opening of the valve i8. As will be explained later, the operating mechanism for valve i8 is set so that the valve never completely closes or opens. Hence, to stop the operation of the apparatus, the switch 36 in the circuit of Imotor I6 must be opened.

When the volume of liquid 'in the receptacle 21 representing Inventory increases due to the rate of iiow from the Supply shelf exceeding the rate of flow from the receptacle 21 to the Demand distributor, the oat 28 sinks in the Stable Money tank l2. When this happens marketwise, the price of the goods drops. Hence, means are provided for indicating the depth of submergence of the tank in terms of price. Such means include a pointer 40 attached to the iioat and a Price scale 4I graduated so vthat the price is'a maximum when thev receptacle 21 is empty and a minimum when it is full.

As the receptacle 21 is on top of the iioat 28,

the combination is top-heavy. Means are, therefore, required for maintaining the float in upright position without interfering with its vertical rise and fall with changes in the amount of liquid in the receptacle 21.

. According to the present invention, this is accomplished by a parallel linkage support extending through a slot 43 in the wall l l, shown more particularly in Fig. 4. A bar 44 is provided having two cross-rods 45 and 46 passing therethrough and rigidly connected thereto. Above the bar 44 is a link 41 likewise provided with cross-rods 48 and 49 rigidly connected thereto. The ends of rods 45 and 48 are journalled in bearings (not shown) mounted on the rear side of the wall ll. The ends of rods 4S and 49 are similarly journalledy in bearings (not-shown) mounted on the back wall of the float 28. As rods 45 and 48 are spaced apart the same distance as 46 and 49, and are located in parallel vertical planes, the oat is maintained in upright position at all times irrespective of the extent .to which it is sub-l merged in the liquid in the tank l2. Lateral wobble is eliminated by the fact that the bearings for the ends of the rods 45, 46, 48 and 49 are spaced apart a considerable distance.

The back wall of the oat is spaced well forward of the rear-edges of the top and sides of.

the float for various reasons. In the rst place, it enables the distance between the rods 45 and 48. on the one hand, and the rods 46 and 49, on the other, to be made greater lthan would otherwise be the case. This flattens out the curved path of movement of the float. In the second place, lit reduces the eiective crosssection of the tloat and hence increases the variation in the depth of submergence of the float :for any given change in the amount of fluid in the receptacle 21. In other words, it makes the apparatus more responsive to variations in the ratio between supply and demand. On the other hand, reduction in the eiective cross-section of .the float reduces its weight-supporting power. To overcome that objection, a counterweight 39 is provided to produce a lifting force nearly equal to the weight of the float and receptacle when the latter is empty.

Movement of the rod 44 controls the opening and closing of the valves is Vand 29. Before this control mechanism is described, the valve operating `means and the electrical circuits by which such means are controlled will be described.

The stem of valve 29, as shown in Fig. 8, has on its rear end a worm wheel y513 ldriven by a worm 5l on a vshaft 52 lcarrying another worm wheel 53 in mesh with a worm 54 on the shaft 55 of a motor 5S. Similar operating mechanism (not shown) is provided .fo-r valve I8.

The control circuits for the two motors are identical so only one is shown diagrannnatically in Fig. 3. The armature winding is indicated at Si?. To permit reversal there are two eld windings 5! and 62. For convenience in description, it will be assumed that itis the Demand valve which is being operated and that the winding i is the one required for opening the valve. There are three switches in series with this winding. Switch 63 is the limiting switch which .is normally closed and is opened only when the valve nears its fully open position. Switch 64 is closed automatically when the float sinks (inventories rising and prices dropping) to cause the Demand valve 'to open. Switch 65 is normally open but is arranged so that it may be closed manually by a push button whenever it is desired to increase Demand arbitrarily.

Switches 10, 1l and 12 have exactly analogous functions with respect to the eld winding 62 which, on energization, causes the valve to close. In series with the armature there is yet another switch 66 which is `normally closed but arranged so that it may be opened manually whenever it is desired to hold Demand constant arbitrarily.

The push button panel is shown in Fig. 5. The buttons B5, B6 `and 1'2 are the operating members of the switches of the same numbers on Fig. .3.

The motor, control circuits and push button switches for operating valve 'I8 are the same as those described in connection with valve 29, so that no illustration or description thereof is necessary.

The switches and circuits above described take care of operation of the valves. The apparatus also includes a series of signal lamps arranged alongside of a number of descriptive legends ex.- plaining what is happening, economically speak'- ing. As shown in Fig. 1, there are ve of such lamps 15, 16, 11, 18 and 19. For operating these lamps four switches 80, '81, 82 and 83 are provided; Two of these switches and 83 are electrically connected so that they operate as single-throw switches, while the otherA twor are double-throw connected. Conveniently,l these switches are ofv 5 the snap-action type described in Eaton U. S. Patent 2,172,673. These switches have a contact arm which snaps back and forth between two contact points as pressure is applied to or taken off a pin attached to such arm and projecting beyond the body of the switch.

The circuit diagram is shown in Fig. 9. It will be noted that lamp II is in series with both switches 8| and 82 so that if either switch is thrown to light its corresponding lamp I6 or 18, the circuit through lamp 11 is broken.

Lamps 'I6 and 18, as their corresponding legends indicate, represent movements in prices. Lamp 'I1 represents stable conditions with supply and demand substantially in balance. Lamps 'I5 and I9 indicate excessively high and abnormally low prices.

There is another switch 85 in series with lamp 'I1 which is closed only when the price is within the range`8 to 84. This additional switch is used to prevent the lamp 'I1 lighting when conditions are more or less stationary but at the same time unduly high or low.

One of the functions of the present apparatus is to give visual signals indicating not only movement of prices but also the direction in which such movement is taking place. Another function is to give a visual signal indicating lack of movement or stable prices.

The mechanism devised for this purpose consists essentially of a pivotally mounted part normally centered by a spring or springs between two contact points on an arm pivoted to swing about the same axis as said part and connected to the moving member whose movement is to be indicated. A dash-pot is connected to said part to slow down the movement of the latter so that on all movements of the arm, except the very slowest, the dash-pot will oier greater resistance to such movement than the centering springs so that said part will lag behind the arm and consequently contact one or other of the contacts. Which contact is engaged depends upon the direction in which the arm moves. As soon as the arm comes to rest, the springs slowly move the dashpot until such part is once more centered between the two contacts.

In the particular construction illustrated, a disk 90 is flxedly mounted on a rotatable shaft 9I to which is rigidly connected a rocker arm I I0. See Fig. 7. One end of this arm is connected to the piston rod I I I of a dash-pot I I2. The other end of the arm I I8 carries a counterweight I I3 to offset the weight of the piston and piston rod of the dash-pot.

Loosely mounted on the shaft 9I is another rocker arm 92, pivotally connected at 93 to the link 94 which, in turn, is connected at 95 to the arm 44. Consequently, vertical movements of the float produce corresponding angular movements of the rocker arm 92.

On the outer end of rocker arm 92 are mounted the snap switches 8I and 82, previously referred to, with their operating pins in contact with or closely adjacent to the top and bottom, respectively, of the rocker arm IIU. When such end of the arm 92 moves upwardly, the switch 8l is closed and the adjacent end of the rocker arm I I is moved upwardly. A downward movement of such end closes the switch 82. Springs I I and l I6 are provided for the purpose of returning the rocker arm H0 into parallelism with the arm 92 against the resistance oiered by the dash-pot H2. In this position the switches 8I and 82 are positioned as shown in Fig. 9.

Arranged around the periphery of the disk are seven cams I00, IIlI, I02, |03, |04, |05 and |06 for operating switches 85, 1|, 64, 83, 80, 88 and 89, respectively. Conveniently the cams are mounted so that their position may be adjusted circumferentially with respect to the disc to produce operation of the switches at any desired angular position of the disc.

I claim:

1. A device for illustrating economic laws, comprising a vertically movable float element whose movements indicate changes in commodity prices and means for visually indicating relatively rapid movements of said element including two members capable of moving together and also independently of each other in substantially the same path, a lamp circuit adapted to be closed whenever the two members are displaced relatively to each other more than a predetermined amount in one direction, a second lamp circuit adapted to be closed whenever the two members are displaced in the opposite direction, a connection between said element and one of said members for imparting movements of said element to the latter, a dash-pot connected to the other member offering relatively high resistance to rapid movement of the last-mentioned member and a resilient connection between said members offering a small but steady force in opposition to displacement of said members relatively to each other in either direction from their equilibrium position.

2. A device for illustrating economic laws, comprising a vertically movable float element whose movements indicate changes in commodity prices and means for visually indicating relatively rapid movements of said element including two members capable of moving together and also independently of each other in substantially the same path, an indicator circuit adapted to be closed whenever the two members are displaced relatively to each other more than a predetermined amount in one direction, a second indicator circuit adapted to be closed whenever the two members are displaced in the opposite direction, a connection between said element and one of said members for imparting movements of said element to the latter, a high-inertia element connected to the other member oiering relatively high resistance to rapid movement of the last-mentioned member, and a resilient connection between said members ofiering a small but steady force in opposition to displacement of said members relatively to each other in either direction from their equilibrium position.

JAMES D. MOONEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 532,868 Bull Jan. 22, 1895 1,989,878 Mooney Feb. 5, 1935

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