US1174969A - Signal-transmitter. - Google Patents

Description

W. J. DAVIS'& D. G. KNITTEL.

SIGNAL TRANSMITTER.

APPLICATION FILED JAN. 2. 1915.

Patented Mar. 14, 1916.

m .T G i3 illE 2 gum WITNESSES THE COLUMBIA PLANOGRAPH .60., WASHINGTON, D. c.

invrrnn srarns rarniar canto WILLIAM J. DAVIS, OF PITTSBURGH, AND DAVID G. KNITTEL, OF WILDVJOOD, PENN- SYLVANIA, ASSIGNORS TO AMERICAN FIRE ALARM COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

SIGNAL-TRANSMITTER.

Specification of Letters Patent.

Application filed January 2, 1915. Serial No. 152.

To all whom it may'concern Be it known that we, WILLIAM J. DAVIS, residing at Pittsburgh, and DAVID G. KNIT- TEL, residing at WVildwood, both in the county of Allegheny and State of Pennsylvania, citizens of the United States, have invented or discovered certain new and useful Improvements in Signal-Transmitters, of which improvements the following is a specification.

Our invention relates to electric signal transmitting instruments such as are used in police and fire alarm boxes to send de-' siredsignals to a central station, and which are of the general character of those shown in our United States Patent No. 1,092,919, and in Patent No. 1,092,918 granted to David G. Knittel. The mechanisms usually employed for this purpose comprise, as shown in-th'ese patents, special-signal and box-number wheels, mounted onseparate rotatable shafts, and provided with peripheral projections adapted to move a circuit controlling arm to interrupt an electric circuit at predetermined intervals. The electrical circuits are provided with one or more shunts, and a suitable clock-work mechanism, indicator and pulling handle are provided to control and operate the transmitter.

It has been found that, in transmitters of this general type, the indicator and pulling handle may be so manipulated as to transmit incorrect or confused signals; and dishonest employees avail themselves of this circumstance when, at an appointed hour for mak-- ing a report to a central station, they have not gone to the box from which such report I should be made, and therefore desire that the signal shall not indicate the number of the box at which the report is actually made.

It is the primary object of our present in vention to provide a signal transmitting instrument which, although adequate in every respect for its intended purpose, may not be so manipulated that it will ransmit an incorrect or confused boX-num er signal.

A further object is to simplify the general construction, and to improve the operation of such signal transmitters.

In the accompanying sheet of drawings, forming part of the specification, the preferred embodiment of the invention is illustrated as applied to police boxes.

Figure l is a face View of the support or door to which such mechanisms are usually attached, the figure showing the operating handle and the indicator in full lines, and some of the mechanism in dotted lines; Fig. 2 is a view partly in section and partly in side elevation of the construction shown in Fig. 1; Figs. 3 and 4 are sectional views taken, respectively, on the lines III-III and IVIV, Fig. 2; Fig. 5 is a sectional view to enlarged scale,.taken on the line V-V, Fig. 4; and Fig. 6 a sectional View in the plane of the winding shaft, showing a detail of construction.

In the several figures like numerals are used to designate like parts.

Referring to the drawings, the entire mechanism is shown as mounted on a suitable support 1, which may be an interior door of a police reporting box, the indicator 2 and pulling handle 3 being on the outer, and the remainder of the mechanism on the inner, face of the door. The clock-work mechanism, indicated particularly in Fig. 2, may be of any suitable type, and is preferably so constructed that a turning of the handle 3 through a predetermined arc will cause the clock-work spring 4 to turn a shaft 5 through one complete revolution. This shaft is in this instance provided with a boxnumber wheel 6 and a single special-signal wheel 7, which are suitably provided with means preferably in the form of peripheral projections, to move an arm 8, pivoted, as at 9', to an angular mounting piece 10, which is adjustab'ly secured to a plate 11. However, it will be understood that the shaft 5 may be provided with suitable means other than the irregular signal wheels for moving the arm 8 as desired- To afford the desired adjustment of the arm 8, the mounting piece is provided with Patented Mar. 14, 1916.

19, held yieldingly in circuit-closing posi- To raise the arm 8 for interrupting the circuit, the signals wheels are provided with projections, which may be arranged to of feet the transmission of any desired signal or signals. In so far as, in the present embodiment of our invention, the box-number '7 signal is transmitted each time. the box is pulled and the transmission of special or 'code signals is'at the option of the person sending. the signal, the operation of the transmitter 15 the same as that'o'f the transmitters shown the above mentioned patents. However, in the present transmitter, the construction is such that the special-signal wheel is adapted to send but one signal, andthat a relatively prolonged call alarm,

intended to indicate that the person at the signal transmitting box desires to be placed in telephone communication with the central station. To such end the special signal wheel 7 is provided with a relatively pro longed projection 20, Which, through suitable means to be explained presently, is adapted to raise the arm 8.

The adjustment of the transmitter to send the special signal. or telephone call may be effected by means of the indicator 2 secured to one end of a rotatably mountedshaft 21, which has a lever 22 attached to its opposite end, and which maybe held yieldingly in one of its two alternate positions by means of a spring 27. At the end of this lever there is slidably mounted a dog 23, provided with a pin 24;, which extends through a longitudinally disposed slot 25 of such lever, and into an arc-shaped slot 26 of the arm 8. The arc 26 is struck with a radius having its center the axis of the shaft 21, the arrangement being such that no movement of the indicator 2 will be effective to move the circuit-controlling arm 8. By moving the indicator to the telephone position shown in dotted lines in Figs. 1, 3 and a, the lever 22 willbe brought to a position wherein the dog 23 will be in the path of the projection 20,so that,when the handle 3 is pulled to set the mechanism in operation,

. such projection will, as the shaft 5 turns in is effected by the projecting teeth of the boxnumber wheel 6, which teeth engage a roller 28 suitably mounted on the lower side of the arm.

It is desirable in police boxes that the signaling instrument be set normally to transmit only the box number, such signal indicating that'the patrol wagon is wanted. Therefore, to the end that, after the instrument hasbeen set to transmit a special signal in addition to the boxnumber, the mechanism will be automatically reset for the box number above, the special-signal wheel is provided with an abutment 29 adapted to engage the side of the dog 23 and thus move the lever 22 to the position indicated in dotted lines'in Fig. 4. When the lever 22 is in this position it will be understood that the indicator 'arm 2 will be in the full line position of Fig. 1. j r 7 It has already been explained that nomanipulation of the arm 2 can in any way'interfere with the transmission of the correct box-number signal when the instrument is in operation. It is equally true that the circuit may not be interrupted by manipulating the arm.2 when instrument is idle. It remains now to explain the construction of the pulling mechanism to the same ends.

F or this purpose, in the present embodiment of our invention we interpose a clutch between the pulling handle and the winding or starting shaft, and a second clutch be tween such shaft and the clockworkniecha nlsm means are provided to release thefirst named clutch upon a predetermined rotation of the pulling handle and immediately after the second named clutch has become operative; and furthermore means are pro vided to hold the first named clutch in released position until the transmitting mechanism has passed through a complete cycle 7 of operation. I

Referring now to the drawings, and par-f ticularly to Figs. 2 and 3, the arm 3 is secured to a rotatably mounted shaft 30, provided at its inner end with a plate 31, which is integrally formedwith such shaft, and held yieldingly in the position shown in Fig. 3 by means of a spring'32. Pivotally secured to such plate, and heldyieldingly toward the center of the shaft 30, there is a pawl having a. finger 33 adapted to fit into a' recess 34: of a collar 35 secured to the wind ing shaft 36. Such pawl has, also, a second finger 37, which, when the handle 3 has been pulled through a predetermined arc,

opening 41, through which the pawl-finger 33 may extend, and with a detent 42 adapted to engage a stop 50 and to hold the locking ring in its indicated position against the tension of a spring 43 secured to such ring. The stop 50 is provided with a platelike portion 51, whereby it is secured to the door 1, and which portion acts as a stop to hold the plate 31 in its indicated position.

lVhen the instrument is in its normal position, ready for operation, the several parts of the clutch and lock are in the positions indicated in full lines in Fig. 3. The turning of the pulling arm 3 is eifective, through plate 31, pawl-finger 33 and collar 35, to correspondingly rotate the Winding shaft 36, hen such shaft has been turned sulliciently to cause the motor spring 4 to engage the clockwork mechanism in a manner to be presently explained, the pawl-finger 33 is thrown outwardly by the engagement of the finger 37 with the roller 38. This releases the arm 3 from the shaft 36, and also releases the locking collar 39, which collar, under the tension of the spring 43, immediately flies back to its normal position, and in such position eilectively prevents the pawl finger 33 from engaging collar 35, and hence the shaft 36, until the instrument has passed through its cycle of operation.

The clutch between the winding shaft 36 and the clockwork mechanism is illustrated particularly in Figs. 1 and 6, the latter being a sectional view on aplane passing through the axis of the winding shaft. As shown, such clutch may be a pawl and ratchet construction. Secured to the shaft 36 there is a sleeve 44, to which the inner end of the spring 4 is attached, and which isprovided at one end with a ratchet wheel 45. Surrounding such wheel, and rotatably mounted on the shaft 36, there is a cupshaped spur gear 46, provided with a pawl 47, held yieldingly toward the ratchet wheel by means of a spring 48. The teeth of the ratchet 45 are so spaced with relation to the angular distance between the end of the pawl-finger 37 and the roller 38 that the pawl 47 will engage the next successive tooth of the ratchet 45 immediately before the pawlfinger is, by the striking of the finger 37 against the roller 38, thrown out of engagement with the collar 35.

In describing the operation of the signal transmitting instrument, it will be assumed first that the indicator has been set for the telephone position, that is, the position in which special-signal mechanism will be brought into action. The instrument is set in motion by pulling or turning the handle 3 in a clock-wise direction, which, through plate 31, pawl-finger 33 and collar 35, causes the winding shaft 36 to correspondingly turn until the finger 37 strikes, and is thrown outwardly by, the roller 38. This releases the finger 33 from the collar 35 as well as from the locking ring 39, and thus places the movement of the winding shaft entirely beyond the control of the one sending the signal, it being understood that as soon as the locking rin 39 is released it flies back under the tension of spring 43, to the starting position. Immediately before the pawl 33, 37 has been thrown outwardly the ratchet wheel 45 has been turned sufliciently to permit the pawl 47 of spur gear 46 to engage the next successive ratchet, and thus couple the clock-work mechanism with the spring 4. Such mechanism then drives the shaft 5 through a. complete revolution, during which the arm 8 is first raised by the projection 20 of the special signal wheel to open the electric circuit for sounding the telephone call, such projection acting through dog 23 and pin 24; and the arm is then raised, by means of the teeth on the box-number wheel, a plurality of times to indicate the number of the box from which the signal is sent. The further rotation of the shaft 5 causes the abutment 29 of the special-signal wheel to engage the side of the dog 23 and swing the indicator to alternate or wagon-calling position.

The operation of the instrument when set to transmit only the box number is the same as that just described with the exception that the special-signal wheel is not called into action.

We claim as our invention:

1. In a signal transmitter, the combination of a movable circuit make-and-break member, a rotatable signal wheel, a manually operable indicator provided with an arm, and a dog engaging said member and slidably mounted in said arm, the movement of the indicator being effective to bring the dog into a position to cause the circuit makeand-break member to be moved by the signal wheel but said member being immovable by the movement of the indicator.

2. Ina signal transmitter, the combina tion of a pivotally mounted make-and-break member provided with an arcuate slot, a rotatable signal wheel, a manually rotatable indicator having an arm i'nredly secured to it, and a dog slidably mounted in such arm and provided with a pin engaging the makea-nd-break member through said slot there of, the rotation of said indicator being effective to bring said dog into a position to cause said member to be moved by the signal wheel.

3. In a signal transmitter, the combination of an arm movable to make and break an electric circuit, a rotatable shaft provided with two sets of detents one for moving said arm to transmit a box-number signal and the other to transmit a special signal, the detents for transmitting the boxnumber signal being effective to move the arm upon each rotation of the shaft, a dog manually movable to a position for causing said special-signal detents to transmit a signal in sequence with the box-number signal, and means effective upon the rotation of said shaft to remove said dog from its signal-transmitting position.

4. In a signal transmitter, the combination of a circuit make-and-break member, means including a clock-work mechanism for moving said member, a rotatable shaft for setting such mechanism in operation, a

' shaft.

5. In a signal transmitter, the combina- Copies of this patent may be obtained for tion of a circuit make-and-break member, means Including a clock-work mechanism for moving said member, a rotatable shaft for setting such mechanism in operation, a rotatable operating member including 'a pawl held yieldingly in engagement with the shaft, means effective upon'the rotation of the shaft to release the pawl, a locking member through an aperture of which said pawl engages the shaft, and means for caus 'ing said locking memberto hold said pawl from engagement with the shaft when the.

pawl has been released therefrom and until after a further movement of the shaft.

In testimony whereof we have hereunto set our hands.

WILLIAM J, DAVIS. DAVID e. KNITTEL.

Witnesses PAUL N. CRIToHLow, FRANCIS J. TOMASSON.

five cents each, by addressing the Commissioner of Patents,

Washington. D. C.

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