US2929894A - Electric contact pressure treadle - Google Patents

Description

March 22, 1960 G. L. VEENSTRA 2,929,894

ELECTRIC CONTACT PRESSURE TREADLE Filed June 15, 1959 2 Sheets-Sheet 1' L L W i {I I N 34 lb jrr g: .36'

I r f JZNQ g 152 33*: I l I i ,w-sl 30 v I I 15 10 [5m f l 55 i I l I 29 1e Cigofge L. Veens zwa March 22, 1960 G. L. VVEENSTRA 2,929,894

ELECTRIC CONTACT PRESSURE TREADLE Filed June 15, 1959 2 Sheets-Sheet 2 INVENTOR. 6 30239 L. i chslra United States Patent This invention is directed to electric contact pressure treadles of novel invention.

It is an important object of my invention to provide pressure treadles adapted to be depressed and actuated 'by the substantial weights of the traction wheels of vehicles, and which include a securable base; an elongated yildable and resilient treadle member having a separate lower elongated passage therein; and having a pair of metal contact strips mounted in the passage of said treadle member and having an elongated yieldable rubber-like perforated separating strip "between said contact strips, said separating strip having a plurality of longitudinally spaced large holes therein; and said treadle member being adjustably and removably mounted on said base by a pair of angularly off-set adjustable rails and caps; and said treadle member having a metal pressure-resistant rod mounted in its upper portion above said contact strips.

'A further object and accomplishment of my invention is the provision of an electrical contact pressure treadle 'havingnovel structural features adapted to resist relatively lighter pressures and which are adapted to eifect circuit closing contact of the superposed contact strips only when substantial weights of vehicles or the like depress the upper-portions of said treadle.

'A further object and accomplishment of my invention is the provision .of a pressure treadle of the aforesaid type which is adapted to be quickly and easily adjusted with respect to its supporting surface and having adjustable mounting ,means to thereby provide change of its operativeness to respond to different weights which cause circuit closing electrical contact.

flItis an object of my invention to provide an adjust- :able treadle to which the side rails mounting the treadle are adjustablymounted to selectively expose greater or less areas of the yieldable treadle to thereby permit the treadle to be selectively adjusted to eifect electrical contact from pressures of weights ranging from approximately 100 to 500 pounds, and which treadle will not operate or respond to relatively lighter pressures.

A-further object is the provision of an adjustable treadle having normally separated electrical contact strips, and having protected circuit wires leading from said contact strips through a sealing yieldable fitting mounted adjacentthe end of the treadle to thereby seal said wires .jagainst moisture and to eliminate the necessity of mounting an'electrical receptacle box adjacent the end of the treadle.

' Other and further important objects of the invention will be apparent from the following specification and claims.

- On-the drawings:

"Fig. 1 is a top plan view of my adjustable treadle, with a portion of one of the end guards broken away.

Fig.2 is a cross sectional view thereof taken on line 2-2 of Fig. 1.

Fig. '3 ,isan enlarged top'plan' view of the end portion of the electrical contact strips and of the separating strip the'rebetween, with parts thereof broken away.

Fig. 4 is a side elevation of the end portions of the contact strips and separating strips, and illustrating frag- 6 ments of the connected circuit wires.

Numeral 10 designates a flat relatively rigid metal base plate of rectangular form having a plurality of holes 11 therein, inward'of its lateral edges. Said base plate 10 is securable to a platform or floor by means of screws (not shown) which pass through said holes 11.

Said base 10 has an end opening recess 12 which receives a sealing bushing or fitting hereinafter described.

Numeral 13 designates an elongated treadle or treadle body which has a longitudinal relatively wide lower passa'ge 14 therein and which has integral lateral beveled edge flanges 15, as illustrated. Said treadle is made of yieldable flexible material such as rubber or rubber composition. Said treadle 13 has an upwardly extending longitudinal middle rib or web 16 which has a longitudinal upper passage 17 therethrough, as illustrated in Fig.2.

Mounted in the upper passage 17 is a relatively thin metal rod 18 which is sufficiently stiff to resist relatively light pressure though will flex slightly when relatively heavier pressures are applied to the treadle, for a purpose hereinafter pointed out.

'Removab1y mounted in the wider lower passage 14 is -a lower thin contact strip 20 which is of non-corrosive metal, for example, brass. Said lower contact strip 20 has .a plurality of upwardly extending projections or lugs 21 which are preferably formed by punching the middle portion of said strip with a suitable punch. A part of said projections or lugs are illustrated at the right of Fig. 3 and in Fig. 4.

Numeral 22 designates relatively narrower metal flexible upper contact strip, which is preferably made of noncorrosive metal such as brass, and which is shown "in cross section in Fig. 2, and a fragment of which is shown in elevation in Fig. 3.

;Positioned and mounted between said lower contact strip 20 and said upper contact strip 22 is a relatively thin band or strip 23of non-conductive material, which is preferablyof rubber.

Said non-conductive and insulating strip 23 has a plurality of longitudinally spaced apart holes 24 formed therein as illustrated in Fig. 3, said hole-s being of greater diameter than the width of the upper contact strip 22.

It is to be understood that a substantially heavy weight applied to a given area of the treadle will bend and depress the portions of the upper contact strip 22 which is below the applied weight to thereby cause portions of said contact strip 22 to bend through one or more of the holes24 and to contact the upwardly extending lugs or projections 21 to thereby close a circuit as hereinafter described.

The lower contact strip 20 has secured thereto by soldering or the like an insulated circuit wire 25, and the upper narrower contact strip 22 has secured thereto by. soldering or the like one end portion of a second circuit wire 26, fragments of which said circuit wires 25 and 26 areillustrated in Fig. 4.

The main portions of said circuit wires are mounted in'a suitable conduit which extends through a platform or floor to either an audible electric signal or to an automatic electrically powered door closer.

Said circuit wires are suitably insulated by the usual tube-like moisture proof cover 27, and then extend through the central passage of a flanged bushing-like plug 28, which said plug 28 has a reduced portion which is snugly mounted in the end portion of an electrical conduit or-pipe 29, a fragment of which said pipe 29 is illustrated in the lower part of Fig. 1. This construction has the advantage of eliminating the installation of a separate junction box.

It will be understood that the usual electrical cables are mounted within suitable conduits or pipes which are installed in the platform, floor, or other supporting surface with the terminal of the producing conduit 29 in a position at one end of the base plate 10. The recess 12 in the base plate is of such size that the insulating and I sealing plug 28 will extend through said recess 12 and be mounted in the end, or terminus of th e'conduit, as illus trated in Fig. 1. This provides a moisture-proof seal to prevent any moisture from entering the conduit and provides for quick and easy installation.

Numerals 3t) and 31 designate two elongated ofi-set apertured anchoring and side rails which have integral upwardly bent flanges 30a and 31a respectively, as illustrated in Figs. 1 and 2. a

The normally lower lateral edge portions of said side rails 30 and 31 have a plurality of transversely extending slots 32 formed therein, and said anchoring side rails are adapted to be adjustably and releasably secured to the base plate 10 by bolts 33 whose threaded portions threadingly engage suitably spaced threaded apertures in base, 10

The upwardly bent and off-set flanges 30a and 31a engage, overlie, and impinge portions of the lateral flanges of the treadle 13, as illustrated in Figs. 1 and 2.

An important feature of my invention is the adjustable mounting of said side rails 30 and 31 in varying positions so that same may be moved and secured either farther apart or closer together, thereby providing foroverlying varying portions of the treadle 13, and providing for exposure of different areas of the middle portion of the treadle.

' When the side rails 30 and 31 are retracted and mounted farther apart, the upwardly extending middle portion of the treadle 13 will be depressed by less weight to effect electrical contact between the contact strips.

When the side rails 30 and 31' are moved and mounted closer together, so as to overlie greater portions of the flanges 15 of the treadle, the flanges 30a and 31a thereby assist in a greater degree in resisting the weight applied to the middle portion of the treadle, and consequently application of a substantial greater weight to the rib 16 and middle portion of the treadle is necessary to effect a contact of a portion of the upper contact strip 22 with the lower contact strip 20.

The upper metal rod 18 is adapted to bend in response to pressures caused by weights exceeding approximately 100 pounds, so that the upper contact strip 22 will be pressed through one or more of the holes 24 and into contact with the projections of the lower contact strip 20.

I have found by experimentation that the adjustable mounting of said side rails 30 and 31, by virtue of the provision of transverse slots therein, permits the treadle to be adjusted in a relatively wide range to respond to different weights from approximately 100 to 500 pounds in order that electrical contact between said contact strips is accomplished. This is highly advantageous in most installations which are in platform and in approach areas adjacent garage doors, and this avoids the objectionable full operation of the treadle by stepping of persons thereon, by bicycles, and by very light vehicles.

The advantage of the weight adjustable structural features of my invention results in only regular automobiles and trucks operating said treadle to effect electrical contact when said side rails 30 and 31 are set and secured in the desired positions.

Numerals 34 and 35 designate relatively rigid' apertured saddle-like end guards or caps of metal which have their intermediate portions arched and extending upwardly to overlie the opposite end portions of the elongated rubber body of the treadle. Said guards 34 and 35' each have a pair of apertures therein, through which V 4 I suitable bolts 36 extend, and which bolts 36 thread in the suitably threaded apertures in the base 10.

Said guards protect the opposite end portions of the treadle 13 against the heavy impacts of traction wheels of vehicles.

An important advantage of my described construction is the relatively quick and easy removability as well as mounting of the elongated treadle 13 so as to permit relatively quick and easy replacement thereof when'a previously installed treadle has been damaged so as to become inoperative.

In removing one of said treadles, the guards 34 and 35 are removed by removal of the bolts 36; the side rails 30 and 31 are removed by removal of the bolts 33, and either the entire treadle 13 may be removed or the two contact strips 20 and 22; intermediate separating strips 23 may be removed and the circuit wires disconnected therefrom. Thereupon a new set of contact strips with intermediate separating strip may be quickly and easily installed in the lower longitudinal passage of the treadle, and the treadle then resecured in the desired position by remounting of the side rails and said end guards in the manner aforesaid.

The opposite ends of the longitudinal passages 14 and ;17 are completely sealed by vulcanizing rubber or rubher-like end sections on the opposite ends of the body of the treadle 13 to thereby prevent water and moisture from entering the passages of said treadle.

In instances Where it is desired that the treadle be adjusted to be made operative and responsive to relatively light weights, the side rails are moved and secured to their outermost widely separated position and also the lower contact strip 20 is positioned closer to the upper contact strip 22 by placing shims below said lower contact strip at spaced apart points.

My afore-described construction provides a durable, strong, adjustable treadle which is water and'moisture proof, and spark proof. This treadle will withstand heavy impacts of vehicles and can be relatively easily adjusted, and the treadle easily replaced in the manner described.

Inasmuch as many changes could be made in the described construction, and as many apparently widely different embodiments of the invention within the scope of the claims could be constructed without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanying specification shall be interpreted as being illustrative and not in a limiting sense.

I claim: V

1. An electric contact pressure treadle adapted for mounting in areas adjacent garage doors or the like; an elongated apertured base, said base, being securable to platforms orthe like; an elongatedpressure treadle of rubber-like material and having oppositely extending yieldable lateral edge flanges, and having an lip-raised middle rib; said rib having a longitudinal passage therethrough; said treadle having a relatively wider lower passage therein; a pair of metal contact strips superposed above each other in said longitudinal lower passageof said treadle; an apertured, flexible, non-conductive separator strip mounted between said metal contact strips and having a plurality of longitudinally spaced holes therein; a pair of circuit wires connected to each of said contact strips; a relatively thin metal rod mounted in the upper longitudinal passage of said treadle above and spaced from said upper contact strip; a pair of apertured anchoring side rails having integral offset edge flanges, said flanges being adapted to partially overlie the edge flanges of said treadle to thereby leave exposed the 1ongitudinal rib of said treadle; and a plurality of screws for removably securing said side rails to said base.

2. An electric contact pressure treadle substantially as recited in claim 1, wherein said base has an enlarged re,- cess at one end thereof; and. a passaged bushing mounted in said base recess, said circuit wires extending through said bushing; and a pair of apertured metal guards secured to said base and overlying the opposite end portions of said treadle.

3. In an electric contact pressure treadle, an apertured base adapted to be secured to a supporting surface; a flexible pressure treadle having yieldable lateral edge flanges; said treadle having a longitudinal lower passage and a longitudinal upper passage therein; an upper metal contact strip and a lower metal contact strip mounted in the lower passage of said treadle; an apertured flexible non-conductive separator strip mounted between said metal contact strips; a pair of circuit wires connected to said contact strips respectively; a metal rod mounted in the upper passage of said treadle; a pair of anchoring side rails having upwardly bent edge flanges thereon, said side rail flanges being adapted to partially overlie the lateral edges of said treadle; said side rails having transversely extending slots therein; and a plurality of screws for adjustably securing said side rails to said base, said side rails being selectively positionable at different distances from each other to expose varying portions of said treadle.

4. In a pressure treadle adjustable to operate in response to a wide range of ditferent pressures; a rigid apertured metal base; a longitudinally passaged yieldable flexible treadle having a lower passage and an upper passage therethrough; said treadle having downwardly converging integral edge flanges and an upwardly extending middle portion; a lower contact strip having a plurality of upwardly extending projections and mounted in said lower passage; an upper contact strip mounted in said lower passage; a separator strip of flexible material having a plurality of longitudinally spaced holes therein positioned between said upper and lower contact strips; a relatively small metal rod in the upper passage of said treadle and spaced above said upper contact strip; a pair of circuit wires connected to said contact strips respectively; a pair of adjustable apertured rails having integral offset flanges partially overlying the edge flanges of said treadle; said rails having a plurality of transversely extending slots therein; and screws extending through said slots and ad justably and removably mounting said rails to cause the offset flanges of said rails to impinge the edge flanges of said treadle; said rails being adjustably positioned to releasably secure said rails farther apart or closer together to thereby expose varying portions of the middle portion of said treadle to thereby make said treadle operative in response to different pressures applied thereto.

5. An adjustable pressure treadle substantially as recited in claim 4, and having apcrtured metal guards removably secured to the opposite ends of said base and having portions of said guards overlying the opposite ends of said yieldable treadle respectively.

6. In a pressure treadle adjustable to be operated by ditferent pressures; a rigid apertured metal base; an elongated yieldable body having a longitudinally extending lower passage and a longitudinally extending upper passage therein; said treadle having its lateral edge portions relatively thinner than its middle portions; a lower con tact strip mounted in said lower passage; an upper contact strip mounted in said lower passage; a non-conductive separator strip having a plurality of spaced holes therein and positioned between said upper and lower contact strips; a metal rod in the upper passage of said body; a pair of circuit wires connected to said contact strips respectively; a pair of adjustable pressure metal rails each having integral upwardly extending flanges partially overlying the lateral edges of said body; said rails having transverse slots therein; screws extending through said slots and removably engaging said base and partially overlying the lateral edge portions of said body; and apertured metal guards overlying the opposite ends of said body respectively and removably secured to said base; said rails being selectively positionable at different distances apart to thereby make said treadle operative in response to different pressures applied to the middle portion of said body.

7. In a pressure treadle adjustable to operate in response to a wide range of different pressures; a rigid apertured metal base; a longitudinally passaged yieldable flexible treadle having a yieldable upwardly projecting middle portion and having laterally extending edge portions; a lower contact strip in the passage of said treadle; an upper contact strip in the passage of said treadle; resilient means between said contact strips for normally separating the same; circuit wires connected to one end of each of said contact strips respectively; a pair of transversely slotted apertured rails having upwardly extending integral flanges, said rail flanges partially overlying the edge portions of said treadle; bolts for adjustably and removably securing said rails to said base, said rails being adjustable toward and away from each other to thereby vary the extent of pressure necessary to be applied to the middle portion of said treadle to effect contact between said contact strips.

References Cited in the file of this patent UNITED STATES PATENTS

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