US1999661A - Signal controlling apparatus - Google Patents

Description

Patented Apr. 30, 1935 g I v v I UNITED-STATES PATENT OFFICE Application December 12, 1929, Serial No. 413,505 Renewed October 3, 1934 7 Claims. (Cl. 177-329) This invention relates to improved signal ac- Accordingly operation of this device depends upon tuating devices and more particularly to arrangetransmission of pressure through the continuous ments for operating trafllc signals. surface layer rather than involving the provision It has heretofore been proposed to arrange to of a separate independently movable strip in the operate automatic traffic signals by means of movroadway. Accordingly, I preferably arrange. an 6 able elements located in the roadways at a diselongate metal receptacle beneath the surface of tance from an intersection, each of these elements the right-hand portion of a roadway adjoining being depressible by a vehicle passing over the an intersect-ion, the thickness of the wall of the same, to close a switch which forms part of a; receptacle being so determined in relation to its 10 system for energizing the traffic lights. An ardepth in the roadway and its width that it may 10' rangement of this character ordinarily has necesbe susceptible to pressure .resulting from the sitated the provision of some factor for effecting movement of vehicles over the same in such a the continued energization of the light as the-ve manner that such increases in pressure will be hicle passes between the movable actuating e1e-' effective to decrease the volumetric capacity of ment and the intersection. Furthermore the dethe receptacle-0r to increase the pressure 01 16 pressible elements disposed in the roadway have uid or fluid contained therein. Preferably such been unsatisfactory and undependable due to the fluid is relatively non-compressible and extends possibility of material such as dust or mud lodg thro a Suitable duet to a current cl i ing upon or between the moving parts and previce so that the increase in pressure applied to 20 venting the normal operation thereof, as well as the receptacle will close a circuit to ener- 20 due to the effect of surface moisture, snow or gize the signal light at the vehicular in the like and also due to the likelihood of the contersection. Preferably this device may comprise ventional street cleaning appliances detrimentally a trap connected to the liquid containing reaifecting mechanism of this character. ceptacle and containing a current-conductive liqv The present invention affords means which uid such as mercury, S thet p e -l p 25 may be arranged below the surface of the roadtien of Pressure to receptacle, the rcu y way and which may be self-contained orfully ,r S in e g 0 the p to Permit Current enclosed; accordingly the system need not be subt D35 between Suitable immersed Contacts, thus jected to the adverse variant conditions of moisclesing'the c rcu t w ich cludes t e appropriture, dust, and mechanical attrition of all sorts ate Signal g Pl'eferably I 3150 Provide means 30 which occurs at the surface of the roadway. Furfo p i t g t device automatically to C thermore, the controlling factor for this device pen-sate fer gradual Changes in temperature may be elongate and disposed longitudinally of a and/or pressure, although these changes are not roadway, thus affording means that may continulikely to be great, when the liquid containing ally be actuated by a vehicle until it reaches the receptacle is located below the surface of the 35 intersection and thereby permitting the continued roadway. energization of a signal light or the like without In the accompanying drawing: necessity for a special delay factor, secondary Fig. 1 is a somewhat diagrammatic view ofa relays or timing mechanisms or the like. vehicular intersection showing my improved sig- 40 In order to accomplish this result, I preferably nal controlling devices arranged in relation 40 arrange a pressure sensitve receptacle at a suitthereto; able depth below the surface of the roadway, hav- Fig. 2 is a sectional view somewhat diagraming found that the weight of an ordinary vehicle matic in character indicated by line 2-2 of Fig. will cause an appreciable increase in pressure 1; and

at a distance belcw the vSurface o h adw y Fig. 3 is a sectional detail ofthe current-clos- 45 or pavement. In accordance with this invenmg d vic r switch. tien, the roadway s in t e m of a pavement In accordance with this invention, a suitable ha a surface layer providing a continuous receptacle I may be disposed beneath the surface unbroken surface, such as for example is affordof the roadway 2 at any desired point, as for ed by a conventional concrete or macadam pavew example adjoining an intersection 3. The recep- 50 ment. Such a layer thereof affords the same tacle may comprise transversely curved upper character of continuous surface over the device and lower sheet members 4 and 5 respectively as in other parts of the roadway, there being no that have flanges 6 welded or otherwise secured definite breaks in the surface to correspond to to each other to provide a fluid-tight construc- 5 the location of the device beneath its surface. tion. Preferably, as shown in Fig. 1, the recep- 5 in relation to the roadway and extending from a point spaced from the intersection substantially to the intersection, and the thickness of its walls is so determined in relation to the depth of installation and the character of pavement and sub-soil that it will be slightly distorted by the weight of a vehicle passing over it.

A tube ID of small diameter may be connected to the receptacle and have an upward continuation H which communicates through a minute opening 12 with a reservoir IS. A suitable breather tube it? permits the surface of the liquid, such as oil, in reservoir 15 to be subject to atmospheric pressure. A downwardly extending portion of the tube It) forms one leg of atrap i! which normally contains an electrically conductive liquid such as mercury.

Preferably the opposite leg of this trap is provided with a pair of conductors 23 and 24 which are connected by leads 25 and 26 to a suitable signal appliance, which in the accompanying drawing for the purposes of illustration is illustrated as a simple warning or signaling light 21, but which obviously may be any suitable system of electro-magnets, relays or the like, as desired. A breather 29 also permits the leg of trap I! which contains the contacts to communicate with the atmosphere; thus the pressure at opposite sides of the trap may be equalized.

It is evident that a vehicle passing over the roadway 2 will cause a suflicient increase in the pressure applied to the top of receptacle I slightly to flatten the same with a consequent decrease in its volumetric capacity, thus forcing fluid through tube 10 and causing the mercury in trap H to rise so that both of the conductors are immersed therein and-thereby closing the circuit between leads 25 and 26. Since orifice I2 is of very restricted diameter, such a relatively sudden surge of the liquid through tube ill will not cause enough flow through orifice 12 to result in an appreciable rise in the liquid level in reservoir i5, nor will such flow occur during the length of time normally required by a vehicle to pass over receptacle l.

Obviously as soon as the vehicle leaves the receptacle, the latter tends to return to its normal shape and the mercury will return to the position illustrated in Fig. 2, wherein it has a substantially equal height in each of the legs of trap'l 'l.

If there is a permanent change in the pressure applied to the receptacle or a change in its temperature results in a tendency of the liquid in receptacle 1 permanently to expand or contract,

opening l2 will permit gradual extrusion of liquid to compensate for such a change, thus permitting the mercury in trap II to retain'itsnormal position except when displaced by the weight of a passing vehicle. As shown, receptacle I may be permanently installed in the earth beneath the roadway and accordingly ordinarily will not involve any necessity for frequent attention adjustment or care. The receptacle i2 and the trap I! may be conveniently located in a suitable container 40 that may be disposed at any desired point, but which may be arranged to permit convenient access to these parts should the same be necessary and to permit the convenient exposure of the surfaces of the liquids in chamber l2 and trap I! to atmospheric pressure.

While for convenience or illustration I have shown a typical example of my signal operating means as connected to a single signal or warning tacle is elongate, being longitudinally disposed light it is evident that it may be arranged to operate any desired type of mechanism through the medium of an electrical controlling apparatus or the like. If desired, a plurality of round or circular receptacles may be substituted for the single elongate receptacle illustrated herein. Each of the same being connected in parallelto the same elongate circuit so that a vehicle passing toward the intersection continues to actuate the signalling device by successfully increasing the pressure to which the receptacles are subjected; it is further evident that in the case of a wide roadway it may be preferable to arrange two or more of the receptacles side by side in order to permit the energization of the signal device by a vehicle which is disposed overany part of the right-hand side of the roadway adjoining the intersection.

I claim:

1. In a combination including a roadway having a continuous unbroken surface and a device operable in response to the passage of a vehicle over the roadway, an actuating mechanism comprising means disposed entirely beneath the continuous surface of said roadway for effecting the actuation of said device, said means being operable in response to deflection of said surface by a vehicle passing over the roadway above said means.

2. In a combination including a roadway having a continuous unbroken surface and a device operable in response to the passage of a vehicle over the roadway, an actuating mechanism comprising a distortable body disposed entirely beneath the continuous surface of said roadway, and means operable in response to distortion of said body by a vehicle passing over the roadway adjacent to that part containing said body for effecting the actuation of said device.

3. In a combination including a roadway having a continuous unbroken surface and a device operable in response to the passage of a vehicle over the roadway, an actuating mechanism comprising an elongate compressible body disposed longitudinally in relation to the extent of the roadway and entirely beneath its continuous surface, said body being compressed by the weight of a vehicle passing over the roadway a jacent to that part beneath which it is dispersed, and means responsive to compression of said body for actuating said device.

4. In a combination including a roadway having a continuous unbroken surface and a device operable in response to the passage of a vehicle over the roadway. an actuating mechanism comprising an elongate liquid-containing receptacle disposed longitudinally in relation to the extent of the roadway and entirely beneath its continuous surface, said receptacle being distortable by a vehicle passing over the roadway adjacent to that part beneath which it is disposed, a duct connected to the receptable, and means operable in response to the flow of liquid through said duct for efiecting the actuation of said device.

5. In a combination including a roadway having a. continuous unbroken surface and a device operable in response to the passage of a vehicle over the roadway, an actuating mechanism comprising a fluid-containing receptacle disposed entirely beneath the continuous surface of the roadway and distortable by the weight of a vehicle passing over the roadway adjacent to that part ing a continuous unbroken surface and a device operable in response to the passage oi a vehicle over the roadway, an actuating mechanism comprising a fluid-containing receptacle disposed entirely beneath the continuous surface of the road,- way and distortable by the weight of a vehicle passing over the roadway adjacent to that part containing the receptacle, a duct connected to the receptacle, and means operable in response to the flow of fluid through said duct for actuating said device, and compensating means for preventing a gradual change in pressure from caus ing a fluid flow in said duct sufliclent to actuate said device. I

7. In a combination including a roadway having a continuous unbroken surtace and a device operableinresponsatothepassageotavehicle over the roadway, an actuating mechanism comprising a fluid-containing receptacle disposed entirely beneath the continuous surface or the roadway and distortable by the weight or a vehicle passing over the roadway adjacent to that part containing the receptacle, a duct connected to the receptacle, and means operable in response to the flow 0t fluid through said duct tor actuating said device, and compensating means comprising a reservoir connected to said duct by a passage of restricted size, whereby a gradual change in pressure or long continued application of pressure is prevented from causing an accidental or continuedoperation of said device.

nears v. measmzv.

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