US2067336A - Apparatus for study of traffic - Google Patents

Description

Jan. 12, 1937. 1. M. PAVER 2,067,336

APPARATUS FOR STUDY TRAFFIC Filed Dec. l, 1955 2 Sheecs-Sheerl l l ETF' F11 I!! l k/Q/m M, Paf/@f L f 2022020 by wmwgy Jan. 12, 1937. J, M PAVER 2,067,336

APPARATUS FOR STUDY OF TRAFFIC Filed Deo. l, 1953 2 Sheets-Shea?l 2 I z/en for: Ja/zvz M. Pave?" Patented Jan. l2, 19.37

UNI-TED STATES PATENT OFFICE APPARATUS Fon STUDY F TRAFFIC John M. Pavel', ilVilmette, Ill.

Application December 1, 1933, Serial No. 700,449

7 Claims.

diagrammatic in character, of a roadway showing one arrangement of traffic contact strips by which lthe flow of traflic is measured;

Fig. 2 is a diagrammatic view of electric circuits which 'may be employed in the arrangement shown in Fig. 1; l

Fig. 3 is a fragmentary longitudinal section of a contact strip taken on the plane 3-3 of Fig. 4;

Fig. 4 is a fragmentary broken plan section of a'contact strip;

Fig. 5 is a similar view of a connector strip carrying electricalconductors for connecting sections of contact strips;

Fig. 6 is a transverse section of a contact strip; Fig. 7 shows a wiring diagram for one forniY of recorder illustrated in the following figures;

Fig. 8 is a plan view of such recorder; Fig. 9 is a. side elevation, certain portions having been broken away to facilitate illustration; Fig. 10 is a view similar. to that of Fig. 9 but showing the recorder. in the act of printing;

Fig. 1l is a perspective view of the time control recorder actuating switch; and

Fig.- 12 shows in somewhat diagrammatic form a simple electrically actuated" counter.

The'inventionis here shown embodied in apparatus which may be readily installed at or removed from any strategic point without impairing or altering he pavement of the roadway or without special structure inthe pavement to receive it. It may therefore be installed at what are considered to be the most advantageous points for trailic study without special preparation as regards the roadway and independently of an outside source of power. Moreover, it may be installed or removed with no substantial interruption of trailic and it may be operated without interference to or vspecial regulation of the traffic. Since the apparatus is quite inconspicuous, it may safely be applied in highly' public locations without attracting attention or invitingtamperlng. For these and other reasons which will presently appear, the apparatus is highly eillcient (Cl. 2355-92) r for counting densetralc flowing simultaneously in a plurality of traffic lanes, this tralc being of a character which it is most often desired to count effectively and efficiently.

In general, the illustrative apparatus comprises an electrically operated counting or recording apparatus and an improved contact strip l0 actuated by the passage of traffic, i. e., vehicles, to

operate the counter or recorder. As here shown, the so-called contact strip com- 10 prises a pair of spaced electrical conductors at least one of which is movable relatively to the other and is resilient so that it will not be permanently distorted by passing traffic. In the present instance these conductors are in the form of spaced strips lvl and l2 of resilient metal, such as phosphor-bronze of such character as will not. be permanently distorted or deformed by the .forces exerted upon it by passing traffic.. Such strips may advantageously be one-fourth of an inch wide and .010 of an inch or thirty gage in thickness. Thestrips are held in separated relation by resilient or compressible spaced members here shown in the form` of short-blocks I3 'of sponge rubber which in the present case are about three-eighths of an inch in length 'and` separated toiallow about flve-eighths of an inch gap between adjacent blocks. Theblocks may advantageously be approximately one-sixteenth of an inch thick. Surrounding the strips and the interposed blocks is a protecting sheath or envelope Il which not only keeps the contact faces of the conductor strips Il and I2 clean, but prevents the entry between the ystrips of foreign substances which might prevent the strips from being brought into electrical contact by passing trafilc. The strip u"i is preferably shaped in section so as to have a flat bottom I5 and a gradually inclined approach tothe top I6. `The height or thickness of the strip is made as small as practi- 4,0

cable so as to offer a. minimum amount of obstruction to tralc and thereby reduce the forces exerted upon it by passing traffic. It may advantageously be about five thirty-seconds of an inch at its thickest point, i. e., the middle, and about one and one-quarter inches in width.

When laid on a roadway, the pressure exerted bypassing traflc, such as the wheels of vehicles, temporarily deforms the strip by-pressing the rubber and spacer blocks at one or more points so as to bring the strips Il and I 2 into electrical contact at one or more places. 'I'he resilient character of the strips ll and I2, the slight obstruction which the strip presentato traffic, and

the protection afforded by the resilient envelope, l

insures that the metal strips will not be permanently deformed or distorted into continuous electrical contact after release of pressure. While rapidly moving tranin is capable of exerting tremendous force against obstructions, the present strip rising as it does less than three-eighths of an inch above the pavement, oiers so little obstruction that the force delivered by the wheels of passing vehicles is relatively slight and well Within the capacity of the materials of the strip to resist wear and deformation.

The contact strip I Il may, of course, be made in any appropriate lengths; but it can be advantage ously made into lengths whichslightly exceed the space between the tire contact areas, namely, an effective length of about fifty-five inches, to enable its use advantageously in counting the trafiic in each of the plurality of lanes on a given thoroughfare. The tire-on-pavement contact being of substantial width and not a narrow line. this length is of course less than the nominal tread gage of the vehicle. Since about one and one-half inches of the length of the illustrative strip at each end comprises the terminal connec tors which do not function as contactors, the actual length of the contact strip should be about fifty-eight inches. In Fig. 1 is shown one arrangement of this character. The roadway I'I is Wide enough to allow six lanes of trafiic, i. e., three in each direction. The contact strips I are spaced transversely of the roadway by inactive connector strips I8 whose `length is barely less than the maximum pavement contact gage for the average standard automobile, being the distance from the outside of one contact area to the outside of the opposite contact area. Taking into account the three inch inactive length of the contact strips I0, the connector strips I8 (see Fig. 2 and serve to connect each of the contact strips I 0 with a. counting or recording apparatus located as at I9 in a convenient point along the roadway. One form of wiring diagram by which the elements of the apparatus are connected is shown in Fig. 2. As there shown, each of the contact strips I0 is connected to a separate counter or recorder 20, three in the present case for one side or half of the roadway.

Since the counters or recorders are to be actuated by a low `voltage battery, it is preferable where along series of contact and connector strips are employed, to interpose a relay 2| between each contact strip and its counter or recorder. 'I'his avoids possibly faulty operation which might occur by direct connection between the contact strips, counter and its battery, owing to the relatively high resistance (compared to that of the battery and the counter magnet) of a circuit comprising a long series of contact and connector strips. The resistance of such circuit would vary of course with each contact strip because the length of each of the circuits would vary. The relay magnet, on the other hand, being low powered (since it need only close the circuit through a recorder and the battery) can have a Winding of relatively high resistance so that variation of the resistance of the circuit comprising the contact and connector strips is negligible. Such relay may of course be operated by a higher voltage battery whose life would of course be long since the energy demand is slight compared to that on the battery for operating the counters.

For narrower roadways and also for a single circuit having a xed resistance, the relays need not be interposed. Relays of this character are common on the market and their details form no part of this invention.

When a relay is employed a battery of one or two dry cells is suiiicient to actuate the counting or recording apparatus. Only a single battery `need be employed for all of the counters or recorders since their circuits (except for the battery) are independent.

The foregoing arrangement (Fig. 2) may ad vantageously be employed for counting or re cording heavy traffic such as that occurring on a Wide roadway having a plurality of lanes of traffic now in the same direction. The simultaneous crossing of the line of contact strips by a plurality of vehicles does not result in a loss of count since each of the vehicles engages a different contact strip which is in circuit with a different recorder. The connector strips traversing what may be called clear pavement lanes (i. e., the width of pavement straddled by the vehicle as it crosses the line of strips or counting line), are not wide enough to permit a vehicle to pass over them without contacting with an adjoining contact strip. On the other hand, each connector strip is long enough so as to minimize the double counts made by a vehicle exactly straddling it and operatively contacting with each of the adjoining contact strips. Furthermore, the contact strips are made as short as possible (but long enough so as not to be straddled completely by a vehicle) so as to minimize the loss of count which would result in adjacent vehicles running 4hub to hub and striking the same contact strip simultaneously.

In arranging Contact strips for a thoroughfare of a given width, the contact strips and connector strips of the lengths above given are assembled alternately. The total length of assembled strips should be great enough so that the connector strips spanning the clear lanes adjacent each of the curbs should not greatly exceed the aforesaid maximum pavement contact gage for the average vehicle. l Their length may exceed it a small amount, say about eight inches, since it is found that the tires of running vehicles rarely come closerthan eight inches from a curb. In adjusting this arrangement for thoroughfares of varying Widths, these clear lanes adjacent to the curbs may lvary from the maximum of sixty-six inches to zero.

It will be apparent that the foregoing arrangement seeks to avoid engagement with a contact strip of all the wheels of the vehicle. Duplication and loss of count is minimized if only a single set of wheels (front and back) strike a* contact strip. With the above described arrangement of contact strips, it is possible to count dense and heavy tranc at the most effective points and to avoid the practice of counting traffic -in intersections. With far less attention than would ordinarily be necessary for counting traffic in intersections, the above described apparatus may be installed on opposite sides of a given intersection on each of the intersecting roadways and thus obtain simply and Without'attendants a complete picture of traffic flow involving the intersection.

To avoid numerous circuits for a wide thoroughfare, it may be desirable toplace a recording apparatus on each side of the thoroughfare, so that each recording apparatus need be connected with contact strips for only onehalf the width Vof the thoroughfare.

For less congested thoroughfares where the' number of vehicles simultaneously crossing the line of contact strips is negligible compared with the total trafilc passing, a single or continuous series of contact strips and single counter may be employed.

To simplify the connecting and placing of the contact and conductor strips, the contact strips are advantageously provided with conductors 22 embedded in the protecting envelope and running along the contact strips il and i2. The number conductors generally need not exceed two for arrangements such as that shown wherein three (a series of not more than three) contact strips ar\ employed. 'Ihe connector strip i8 is advantageously of approximately the same contour as the contact strips and carries a plurality of flexible wires 29. For an arrangement such as that here shown, not more than four wires are needed. In both the contact strips and connector strips the metal strips ii and I2 and the wires terminate in jack tubes 24 having a ilxed spacing, rBy the use of dowel pins 25 a plurality of contact strips and connector Jstrips may be electrically connected easily and simply.

The contact and connector strips are preferably attached to the pavement by the use of a plastic cement which at no time becomes brittle. A tacky rubber cement is advantageous for this purpose and is sufficiently strong to hold the strips in place against the horizontal forces exerted by trailic. In this connection it should be remembered that the traffic exerts not only downward compression on the strip but a horizontal force, the latter resulting from the horizontal driving eiort or kick given by a vehicle tire as it leaves the strip. By comparison, the horizontal force delivered as the tire strikes the strip is much smaller. The transverse or horizontal resilience of the strip, attributable largely to the resilient bronze contact strips, is sufflcient to restore to normal position any portion of the strip which may be momentarily slightly displaced by passing traffic.. This prevents creeping of the strip in a direction opposite to the direction oi traiiic. To facilitate the application of the contact and connector strips to thek pavement, they may be furnished coated with the cement which is protected by a covering 2S of Holland or equivalent tape which may be removed just before application t the roadway, thereby presenting an eiilcient adhesive surface. The cementmay be applied to the bottom of the strip by means of a cheese cloth or other cloth tape 21 impregnated with the cement and serving as a medium for applying a uniform layer of cement. The protecting cover 25 is of course laid upon the cement layer.

The contact strips and also the connector strips may advantageously be made by vulcanizing together strips of gum rubber, which are laid so as to surround the conductors and metal strips, After assembly, the composite strip may be placed in a vulcanizer which molds the strip into proper shape, i. e.; with a yflat bottom and convex top and causes the rubber to flow around the metal strips and conductor wires, thus forming a solid or integral covering or sheath. If the contact strips/"be thus4 formed, it is preferable to'wrap the metal strips il and i2 with their intervening spacer blocks with a. cloth or other wrapping to prevent the rubber from flowing @etween the-metal strips during the vulcanizing process.

'Ihe counting or recording apparatus may be arranged simply to count passing trame or to count and record the count at given intervals. For merely counting, any appropriate magnetically operated counter may be employed, such as that shown in Fig. 12, wherein an armature ac- 5 tuated by/the closing of the circuit through the magnet operates a conventional counter. These are purchaseable on the market and their details form no part of this invention. It is advantageous however to select a design which is l0 compact and whose moving parts have a minimum inertia. Preferably the counter should be designed to require two electrical impulses be-r fore registering a count. 'Ihus only a single count is registered by the impulses -received. by`1" the successiveclosing of the circuit upon the passage of the front' and rear wheels, respectively, of a vehicle. This is effected simply by employing a ratchet having twenty notches instead of ten for actuating the units wheel of lthe 20 counter.

In Figs. 8 to 10, I have illustrated one form of recorder which serves both to count traiiic and to record the same at given intervals. Such apparatus comprises a magnetically actuated 25 counter of the type above described, coupled with a magnetically actuated recording apparatus for' printing the count on a tape or the like at given. intervals. The recorder is actuated by a clock which is associated with the apparatus and con- 30 trols the circuit which actuates the recorder.

As here shown,`a simple counter 28 is provided with printing characters adapted to print upon a tape or the like. The counter is actuated by a magnet 29 and armature 30, the latter being 35 pivoted at 3i. Apawl 32 engages a, twenty tooth ratchet 33, thus requiring twonimpulses for each` registered count of the units wheel 3Q. The counter in the present instance is also of standard construction, the details of which form no 40 part of this invention. The magnet or solenoid 29 is actuated by a battery`35 which is placed in circuit with the magnet and the contact strips ii and i2. as illustrated diagrammatically in Fig. 'i.

The recording apparatus comprises a movable platen 36 hinged at 3l and adapted to be actuated to press a printing tape 38 or the like against the face of the printing characters (see Fig.4 lil). Ink may be supplied by a printing ribbon or in 5o any other convenient manner such as by an inking device 39 in the form of a small pad which is rubbed over thenprinting characters in the region where the impression4 is to be placed, just prior to the operative movement ofthe platen 55 36. The inking pad is hinged at 40 which` is coaxial with the axis of the counter andis actriated by a link 4I by which it is raised out of the path of the platen (see Fig. 10). The platen and inkingmechanism are actu- 30 ated by a magnet 42 and armature 43 hinged at V44. Thearmature is connected with the platen the face of the platen over the feeding roll 50 70 and under the small spring iingers 5| which serve to hold thepaper against the feeding roll during the interval of feeding. The roll 50 is preferably faced with friction material such as crepe rubber or the like which exerts suiiicient friction against the paper tape (the latter being in con-m tact with the roll for about one-half oi its cir-n cumference during' the intervals of feeding) to draw it from the supply cylinder 49 after each impression by a suilicient distance to present a clean surface to the counter type. The tape feed ing roll is periodically advanced on the return. stroke of the platen by eng.` gement with a pawl 52 piv'oted at 53. The engagement s eiected by the downward movement ci" the feeding roll which is mounted at 54 on an extension 55 of the platen carrying arm 45. Tlfie shaft which carries the fingers l is likewise carried on such an extension. The downward movement of the roll under the action offgravty and with the assistance of spring 48, brings the ratchet 56 on the roll in engagement with pawl 52, thus rotating the roll a part of one turn and advancing the tape 36. Movement of the feeding roll in the opposite direction during the printing operation is prevented by the pawl 5T which engages the ratchet 56 at a point opposite pawl 52. The latter is counterbalanced either by a spring or in the present case, by a weight 5B.

It is apparent from the foregoing that when the magnet 42 is energized, its armature through the link 46 draws the platen arm 45 toward the counter type. Before the platen reaches the type the inker 39 is raised out of position (see Fig. 10) by link 4| which is pivoted at its other end to the platen arm 45. During this movement the pawl 51 prevents any reverse rotation of the feeding roll under tensioniof the paper. Upon opening of the circuit the platen arm falls away, lowerf ing the inker 39 and causing the pawl 52 to rotate the feeding roll by engagement with ratchet 56.

'I'he recorder may of course be actuated by any' appropriatemeans either manually or automatically. Preferably its actuation is automatic so as to avoid the necessity of any manual attention. For that purpose a time clock arranged to close the recorder circuit momentarily at stated periods may advantageously be associated with the apparatus. A clock of this character is indicated at 59. The mechanism of the clock itself is standard and forms no part of this in` vention. Instead loi hands, hour and minute wheels 60 and 6| may be employed so that the hour of the clock may be read from above through an opening in the housing in which the apparatus is enclosed. In the arrangement shown, it would be difficult to note the time of the clock for the purpbse of setting it if the ordinary hands were employed. In`the present instance the clock is arranged to take hourly readings and for that purpose the minute wheel is provided with a contact 62 which on each revolution engages contact 63 (see Fig. 11) to close the recorder circuitO To secure merely a momentary closing of the circuit and opening of the same independently of the movement of the clock, the contact 63 is pivoted at 64 and is engaged by ringer 65 carried on one of the extensions 55 on the platen arms when the latter are raised by the closing of the circuit. The nger 65 turns the contact about its pivot in a counter-clockwise direction thus moving it out of engagement with contact 62 and opening the circuit. A helical spring 66 tends to return the nger 65 to its normal position determined by the stop 61 but it is prevented again from engaging contact 62 by the oifset'or step 66 which occurs adjacent the contact 62. As here shown, the surface 69 upon which contact acer/,smi

62 is carried is oiset as at 68 to provide the step which prevents the contact 63 from again en gaging contact 62. Upon completion of the rotation of the minute Wheel, the contact 63 rides along the surface 69 and eventually engages with. contact 62. If records are desired at a greater frequency than one hour, a plurality of contacts 62 will be required at proper intervals on the minute wheel.

The apparatus is here shown with an hour printing wheel l0 driven by the clock at the saine speed as the hour wheel 60, and located coaxial with the counter printing wheels so as to print upon the tape adjacent the record of the count, the hour at which the record was made. Thus the tape itself will contain a complete record of the traffic flow as regards quantity and concentration of traffic.

In Fig. 7 is illustrated diagrammatically the relation between the counter and recorder circuits arranged for operation by the single battery 35.

Where a counter alone (see Fig. 12) is actuated, a much smaller battery may be used and the registering apparatus may be made much more compact. 'Ihis is particularly advantageous where it is difficult to conceal the registering or counting apparatus to prevent unauthorized tampering. A compact apparatus also makes more simple the location of the contact strips between street car tracks in the event it is desired to count vehicular traic on streets having street car traiiic. A compact registering or recording apparatus may be simply suspended under a convenient manhole cover without requiring conductors to be led under a rail to the curb.

Obviously the invention is not limited to the details of the illustrative apparatus since these may be variously modified. Moreover it is not indispensable that all features of the invention be used conjointly since various features may be used to advantage in diierent combinations and sub-combinations.

Having described my invention, I claim: 1. Apparatus for counting trafiic comprising in combination a plurality of thin contact strips each having an effective length of a little less than the tread gage of vehicles laid in a line transversely of the roadway where a count is desired 'and maintained against displacement relative to the pavement, said strips being separated a distance a little greater than the tread gage of vehicles, each of said strips containing a pair of resiliently spaced conductors adapted to be brought into contact at the point of passage of vehicle wheels,

said pairs of conductors being respectively con nected with electrically actuated counters and a source of' energy whereby vehicles simultaneously crossing the counting line will be individually registered.

2. In an apparatus for counting vehicular trafc including, conductors, -a source of electrical energy and an exhibiting means in series with said conductors, the improvement comprising a contact strip extending transversely of the road at the line of count, and having alternately arranged active and inactive sections, each active section containing a pair of normally separated conductors extending longitudinally of the strip, said pair of conductors having an effective length of slightly less than the standard tread of vehicles to be counted.

3. In an apparatus for counting vehicular trafiic including, conductors, a source of electrical energy and an exhibiting means in series with said conductors, the improvement comprising, a contact strip extending transversely of the road at the line of count, and having a series of longitudinally spaced conductors, said conductors extending longitudinally of the strip and being spaced a distance slightly greater than the standard tread of vehicles to be counted.

4. Trailc counting apparatus of the character described comprising in combination a series of spaced contact strips extending transversely across a roadway, the effective length of each strip being approximately that of the standard vehicle tread spacing, said strips being spaced apart by a distance slightly greater than such tread spacing, and an independent counter associated with each strip.

5. Tramo counting apparatus ofthe character described comprising in combination a series of spaced contact strips extending transversely across a roadway, the effective length of each strip being approximately that of the standard vehicle tread spacing, said strips being spaced apart by a distance slightly greater than such tread spacing, each strip having a pair of spaced electrical conductors extending longitudinally thereof and adapted to be brought into electrical contact by a passing vehicle, a counter for each of said strips, and electrical circuits between said strip and counters respectively whereby the counters register traffic engaging the respective strips.

6. Traflic counting apparatus of the character described comprising in combination a series of spaced contact strips extending transversely across a roadway, the eiective length of each strip being approximately that oi the standard vehicle tread spacing, said strips being spaced apart by a distance slightly greater than such tread spacing, each strip having a pair of spaced electrical conductors extending longitudinally thereof and adapted to be brought into electrical contact by a passing vehicle, a counter for each of said strips, and relays in circuit with each of said strips, said relays respectively controlling said counters whereby a low voltage source of current may be employed to actuate said counters.

7. Traiic counting apparatus of the character described comprising a counter actuating device in the form, of a deformable strip extending transversely across a roadway and maintained against displacement relative to the surface thereof, said strip having active sections eachv having an eiective length approximately that of the standard vehicle tread spacing and longitudinally separated by an inactive section of a length slightly greater than such tread spacing,I and a counting device associated with each active section of said strip.

JOHN M. PAVER.

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