US2150633A - Timing device and escapement therefor - Google Patents

Description

March 14, 1939. M. H. RHODES ET AL TIMING DEVICE AND ESCAPEMENT THEREFOR Filed Sept. 26, 1936 2 Sheets-Sheet. 1

FIG].

M. H. RHODES ET AL TIMING DEVICE'AND ESCAPEMENT THEREFOR March 14, 1939.

Filed Sept. 26, 1936 Z'Sheets-Sheet 2 IH 'IIIIII'IIIA III F'l GIO, 1 3/ Patented Mar. 14, 1939 PATENT OFFICE TIMING DEVICE AND ESCAPEMENT THEREFOR Marcus H. Rhodes, New York, N. Y., and John Fanzoi, Hartford, Conn., assignors to M. H. Rhodes, Inc., New York, N. Y... a corporation of Delaware Application September 26, 1936, Serial No. 102,640

1 Claim.

This invention relates to timing devices, and with regard to certain more specific features, to time signals.

Among the several objects of the invention may be noted the provision of a timing device of the class described which may be made to actuate a signal, in the form of a single stroke against a bell or other gong element, upon the expiration of any desired time interval; the provision of a timing device of the class described incorporating a timing train of simple and effective construction, but which nevertheless produces a signal of considerable intensity and audibility; the provision, in a timing device of the class described, of an improved form of escapement, which requires no balance spring for its satisfactory operation, and which escapement is relatively quiet and simple in action; the provision, in a timing device of the class described, of improved means of great simplicity for controlling the signal-actuating elements from the timing train; and the provision of a timing device of the class described which is relatively simple and economical in construction and operation. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claim.

In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention,

Fig. l is a front elevation of a timing device embodying the present invention; Fig. 2 is a side elevation of the device of Fig. 1; Fig. 3 is a back elevation of the device of Fig. l, a certain bell element having been removed;

Fig. 4 is a vertical section taken substantially along line 4-4 of Figures 1 and 3;

Fig. 5 is an ideal section of a timing train and escapement device;

Fig. 6 is an enlarged horizontal section taken substantially along line 6-6 of Figures 3 and 4;

Figures 7 and 8 are diagrammatic views illustrating, together with Fig. 5, the progressive positions in the operation of the escapement device; and,

Figures 9 and 10 are views similar to a part of Fig. 3, illustrating, together with Fig. 3, the progressive positions in the operation of a signal actuating member.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now more particularly to Fig. 1, numeral i indicates the outer face plate of a timing device embodying the present invention. In the embodiment shown in the drawings, the invention is adapted for panel mounting, although it will be seen that by suitable, simple changes in enclosure elements, the invention may likewise be adapted for table or any other type of mounting.

The face plate 9, which is of generally rectangular shape, carries thereon a circular scale indicated by numeral 3. Mounted on a shaft 5 extending forwardly through a hole 6 in the center of the face plate i is a knob 1 having a pointer 50. The pointer 9 cooperates with the indicia of the scale 3. Projecting through a suitable opening in the face plate l is a knob or stop member ii, that provides an abutment for the knob l with the pointer 9 at its zero position.

The manner in which the timing device of the present invention is mounted on a panel i0 is an important feature of the invention. Numeral l2 indicates a circular hole cut in the panel l0. Numetal l3 indicates a generally circular mounting plate that fits flush against the front side of the panel ill. the diameter of the plate l3 being somewhat greater than the diameter of the hole 82. At diametrically opposite points on its periphery, plate i 3 carries pairs of deformable ears M, which fit snugly into slots l5 suitably provided in the panel l0, extending out from the hole l2. The ends of ears l4 are bent down on the rear side. of panel l0, thereby clamping theplate I3 to the panel to. Shaft 5 extends through a suitable hole is in plate 13. Ears l8 are provided from the metal of plate 13 that would have occupied the position of the hole 16, and these ears l8, extending through the hole 6 in face plate I, are bent down to clamp face plate I against mounting plate 43. Stop II is mounted on plate l3.

Numeral l1 indicates'a cup-shaped enclosure element that is secured to the plate l3 by means of screws IS. The open front of the enclosure element I1 is substantially closed by a circular plate 2 I, which is held in proper parallel position by collars or sleeves 23 on the screws 9. The threaded ends of screws I 9 are secured in suitably threaded openings at the ends of a central V- shaped bracket 25. A rivet 2'! at the point of the bracket 25 serves to mount a hell or gong 29 concentrically with the enclosure element IT. The edge of the bell29 is preferably spaced close to the edge of the enclosure element H, as indicated.

Screws 31 extending inwardly from the circular plate I! serve to mount a timing train, which will next be described. The timing train comprises a pair of parallel mounting plates 33 and 35, which are held in parallel relation by supports 31. Plates 33 and 35 serve to support the ends 01' several shafts upon which the various elements of the timing train are mounted.

The timing train itself may be described by reference to Fig. 5, which is an ideal or extended section, and to Fig. 6. The heretofore-described shaft 5 comprises the main shaft of the timing train. To the shaft 5 is secured (see Fig. 5) the inner end of a main spring 39, which is of the usual coiled type. The outer end of the main spring 39 engages a projection 40 struck up from the plate 35. To a drum ll forming part of the shaft 5 is made fast a friction disc 42, which is made of a suitable springy material. The outer periphery of the friction disc 42 is slightly flared, as indicated at numeral 43. Loosely mounted on the drum ll, in position to be engaged by the flared edge 43 of the friction disc 42, is a gear 45. The gear 45 meshes with a pinion 41 on a shaft 49 that also carries a gear 5|. The gear 51 in turn meshes with a pinion 53 on a shaft 55 that also carries a gear 51. The gear 51 in turn meshes with a pinion 59 on a shaft 6| that carries a gear 83. The gear 53 in turn meshes with a pinion 65 on a shaft 31 that also carries a ratchet wheel 59. The teeth of the ratchet wheel 59 are preferably pointed, as indicated in Fig. 5, but other forms of teeth may be used.

Rotation of the ratchet wheel 69 is controlled by an escapement device indicated broadly by numeral II. The escapement device forms one of the principal features of the present invention. It comprises a solid disc 13 mounted on a shaft in turn mounted in bearings on plates 33 and 35 for substantially frictionless rotation. The shaft 15 is mounted in proximity to the teeth of ratchet wheel 59; in fact, it is so close that it is half-cut, as indicated at numeral 11, in order to provide sumcient room for the teeth of the ratchet wheel 59 to pass the shaft I5. Numerals l9 and II indicate a pair of pins that are mounted on the disc I3, extending downwardly at right angles thereto. The positions of the pins 19 and Bi at equal distances from the shaft 15, and on opposite sides of a line connecting the centers of rotation of shafts 51 and 15, are such that, coopcrating with the half-cut 11, they permit only a slow controlled movement of the teeth of ratchet wheel 59 when said ratchet wheel 59 attempts to rotate. The manner in which the device functions as an escapement is indicated progressively in Figures 5, "l and 8. For example, in Fig. 5, the pin 9| lies in the trough between two successive teeth 83a and 83b of the ratchet wheel 59. The next tooth 93c is about to pass the shaft 15, through the half-cut 11. The pin 19 is at the crest of the next tooth 9301.

It is assumed that the ratchet wheel 59 tends to rotate in a counter-clockwise direction under the influence of the main spring 39. In order for the ratchet wheel 59 to rotate, however, it must push the pin 8| aside. In order to do this, it must rotate the disc 13 in a clockwise manner, by causing the pin 3| to ride up the advancing edge of tooth 3317. This movement is indicated in Fig. 7. As the pin 3| rides up the advancing edge of tooth 33b, permitting gradual rotation of the ratchet wheel 59, the tooth 33c passes through the half-cut ll of shaft 15. At the same time, the pin 13 is descending into the trough between teeth 33d and 93e. This motion continues until the position indicated in Fig. 8 is assumed, at which time the pin Si is at the crest of tooth 83b, tooth 83c has passed entirely through the halfcut 11, and pin 19 is positioned in the bottom of the trough between teeth 83d and 83c. Further rotation of the ratchet wheel 69 is now achieved by driving the disc 13 in a counter-clockwise manner, through the engagement of pin 19 with the advancing edge of tooth 83c. Meanwhile, pin 8| will drop into the bottom of the trough between teeth 83b and 830. By the time the pin 19 reaches the crest of tooth 83c, pin BI is in the trough between teeth 83b and 830, and the posi-- tion of the elements is again as illustrated in Fig. 5.

The half-cut I1 is provided in order that the shaft 15 may be mounted closer to the shaft 51 (and hence closer to the periphery of ratchet wheel 59). The closer the shaft 15 is to the periphery of ratchet wheel 69, the greater will be the angle of rotation of shaft 15 as successive teeth 93 escape. The greater the angle of rotation of shaft 15, the longer will be the intervals of time between the escape of successive teeth 83, which is desirable from the standpoint of the timing operation of the escapement.

This escapement cannot overrun, because the ratchet wheel 59 cannot advance without driving the pins 19 and ill in such manner as to rotate the disc 13 in an oscillating manner. With the symmetrical disposition of the pins 19 and 8! about the line of centers between shaft 61 and shaft 15, as indicated, it will be seen that the escapement acts in the same manner whether the ratchet wheel 59 tends to advance in a clockwise or in a counter-clockwise direction.

Basically, the retarding force against the rotation of ratchet wheel 69 is the inertia of the disc 13 resisting change in the direction of its rotation. This inertia can be reduced, and the es capement thus permitted to operate in a faster manner, by reducing the mass of the disc 13. In the extreme case, the mass of the disc 13 may be reduced by cutting away all of said disc except the amount necessary to extend from the shaft I5 to support each of the pins 19 and M. It is to be noted that under such circumstances the disc 13 loses its character as a disc, and becomes merely a supporting member (of bell-crank shape) for the pins 19 and 81. Such an escapement is comprehended within the terms of the present invention.

A distinctly advantageous feature of the present invention, insofar as the escapement is concerned, is that it requires no balance spring or similar element for its operation.

The main shaft 5 extends through the timing train mounting plate 33, and to its outer end is made fast a disc 85. Also mounted on the shaft 5, but free to rotate thereon, is a second disc 81 of slightly larger diameter than the disc 85. The discs 85 and B1 are flush with each other, and both are positioned in a suitable circular opening 89 provided in the plate 2|.

Disc 95 has a notch 9| in its periphery, the said notch 9| having a radial edge 93 and a sloping edge 95. Disc 31 has a similar notch 91 in its periphery, but both edges 99 of the notch 91 are substantially radial. The disc 91 is also provided with an arcuate slot II, which receives a projection I03 struck inwardly from the disc 85.

Numeral I05 indicates a bell-crank lever that is pivoted on a pin I01 supported in the plate II. One arm I99 01' the lever I05 carries an inwardly projecting pin III, that is positioned to engage the periphery of the disc 81. A suitable notch II3 extending outwardly from the opening 89 in the plate 2I makes this positioning of the pin III possible. A tension spring H5 is secured at one end to the arm I09, and at the other end to a pin III mounted on the plate 2|, in order to urge the pin III into engagement with the periphery of the disc 81 at all times.

The other arm II9 of the bell-crank lever I 05 has a projection I2I at its end.

Numeral I23 indicates an arm that swings on a pivot I25 mounted on the plate 2i. The arm I23 carries a striker or clapper portion I2I of relatively large diameter at its outer end, and is provided with an anvil portion I29 near its inner end. The anvil portion I29 is positioned to be struck by the projection I2! on arm N9 of bell-crank lever I05.

When the knob I is at zero position (as indicated in Fig. l), the discs 85 and 8! are positioned as indicated in Fig. 3. Under such circumstances, the pin III on arm I09 of hellcrank lever I05 is positioned in the troughs of juxtaposed notches 9| and 9I of discs 85 and BI, respectively. When, now, the knob I is ro tated in a clockwise manner, referring to Fig. 1, so as to bring the arrow 9 into juxtaposition, say, with the numeral 30 on the scale 3, the following changes take place in the mechanism:

In the first place, the edge 43 of friction disc 42 will slip over the face of gear 45 without rotating said gear, because said gear 45 is prevented from rotating by the deterrent action of the escapement mechanism II at the end of the timing train.

The disc 85, "being fast on the shaft 5i will rotate therewith. As the disc 85 rotates, the pin III will slide out of the notch 9I along the sloping face 95 of said notch, ultimately to be positioned against the periphery of disc 8?. Disc 81, it will be recalled, is slightly larger in diameter than disc 85. The angular position of disc 8? at this time is not material, because, since it is free to rotate on the shaft 5, it will be forced out of the way by the engagement of pin III along the sloping face 95. However, as soon as the projection I03 comes into engagement with the forward edge of the arcuate slot IOI, as indicated in Fig. 9, further forward (counterclockwise) movement of the disc 85 will be accompanied by forward movement of the disc 85.

At the end of the setting movement of knob I (which may be to any desired position on the scale 3), the knob I is released. The turning of the shaft 5 will have placed a considerable tension in the main spring 39, which tension will tend to drive said shaft 5 to rotate in a reverse direction (e. g., to return the arrow 9 to zero position). However, the frictional engagement of the friction disc 42 and the gear 45 is now such that the main shaft 5 can rotate only with the gear 45, and the gear 45 can rotate only by operating the escapement mechanism II through the timing train comprising the gear train 4I5 I-53--5I-59--6395Ii9. This means that the return of the main shaft 5 to zero position will only be brought about in a slow, timed manner.

Return of the main shaft 5 to zero position means, with respect to Figures 9 and 10, clockwise rotation of the disc 85. For the first portion of this clockwise movement, the disc 81 will not move, because the projection I03 will be sliding along the length of arcuate slot IOI. By

the time the projection I03 reaches the end of slot IN, the radial edge 99 of notch 91 will be advanced in position over the sloping edge 95 of notch 9I, as indicated in Fig. 10. Further movement of the disc 85 after this condition has been reached causes coextensive movement of the disc 81}; because the projection I03 will now be engaged with the end of arcuate slot IOI. This movement continues until the knob I is practically back to zero position, at which time the pin III on arm I09 of bell-crank lever I05 will suddenly pass over the radial edge 99 of notch 91, to drop into the troughs of both notches 9i and 91. Since the pin III has dropped over a radial edge 99 rather than along the sloping edge 95, it will drop to the trough of the notches with a quick, snapping movement, under the influence of the spring II5. This snapping movement of the bell-crank lever I05 brings the projection IZI in a fulcrum-like manner, forcibly against the anvil portion I29 of arm I23, with a hammer blow. This hammer blow causes a sudden swinging of the arm I23 with cumulative momentum on the pivot I25, and the clapper I21 hits the bell 29 a sharp, resounding blow. The relatively large size of the clapper I2I, coupled with the sharpness of the movement throughout, and the cumulative fulcrum leverage of the projection I2I on anvil I29, means that the bell 29 will resound with a relatively loud musical note, thus effecting the desired signal. The striking force, it will be seen, comes from the spring H5, which may be made quite strong, as well as from the cumulative fulcrum leverage mentioned. In effect, the discs 85 and 0! and the bell-crank lever I05 constitute a mechanical relay, delivering the relatively strong force of the spring Ii5'upon actuation by the relatively weak timing train.

A feature of the present invention is the positioning of the pivot I25 of clapper arm I23 as far as possible from the center of the device, and as near as possible to the bell 29. This positioning enables clapper I2! to strike bell 29 along a nearly perpendicular line. The perpendicular blow thus given to the hell 2% by the clapper i2I results in a more forceful, sharp signal. When the pivot I25 is so positioned (such as nearer to the center of the device) that the clapper I21 strikes the bell 29 a glancing blow, the signal is not nearly as sharp or forcible. The mounting of the clapper so that it strikes the bell with a nearly perpendicular blow is accordingly one of the principal features of the invention.

In the embodiment as shown in the drawings, the vertical positioning of the elements is such that gravity causes the clapper arm I23 to drop again to the position shown in Figures 3, 9 and 10, immediately after it has struck a blow on the bell 29. If the device is installed under such conditions that gravity may not be relied upon for this return movement of the arm I23, it is preferable that a suitable light spring be provided in order to return the arm I23 to the position shown in Figures 3, 9 and 10, regardless of the operation of gravity.

A feature of the present invention is that the bell-crank lever I05 needs to be moved only through an angle of about seven degrees in order fully to actuate the arm I23. This permits easy setting of the signal with only a relatively slight turn of knob I. Although the lever I05 moves only about seven degrees, it actuates the arm to move through about ten and one-half degrees, thereby giving momentum to the clapper I21. The projection III of bell-crank lever it! engages the anvil portion I29 of arm III in such manner that the force is applied to the arm I23 at progressively shorter distances from its pivot I" as the impulse is delivered, thereby accelerating the speed of the arm I23. These factors contribute to the attainment of a signal of maximum clearness and intensity of sound for a given size of elements.

The mounting means of the present invention is important. It will be seen that, in order to mount the signal on a panel, only one hole I! needs to be cut in the panel l0. Demounting is easily accomplished, merely by unbending the ears I from their clamping position on the panel M.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim: v

In a time signalling device, a timing train, means for manually setting said timing train to run for a predetermined adjustable interval of time, cam means controlled by said timing train comprising a rotatable disc having a notch in its periphery, a V-shaped lever pivoted at the intersection of its two arms so as to turn in its own plane, and substantially in the plane of said disc, one of the said arms of the lever having a cam follower at its end engaging said cam means, spring means engaging said V-shaped lever and tending at all times to rotate said v-shaped lever so as to press said cam follower into firm engagement with said cam, a simple lever pivoted at one end and swinging in its own plane and substantially in the same plane as said V-shaped lever, the other end of said simple lever having a clapper thereon, a bell positioned in the path of movement of said clapper, said simple lever having an anvil edge provided intermediate its ends, the pivot points of said simple and V-shaped levers being located with respect to each other that, as said cam follower drops into the notch in the edge of the cam disc, the end of the other arm of the V- shaped lever is brought forcibly against said an-- vil edge of the simple lever and slides therealong, towards the pivot point of said simple lever. thereby causing said simple lever to rotate on its pivot. as driven by the V-shaped lever, with a constantly decreasing mechanical advantage in the drive engagement, the simple lever thereby acquiring a rotational moment that causes the clapper end thereof to come against the bell with a sharp blow, thus providing a clear, resonant signal, driving movement of the V-shaped lever against the simple lever being stopped by the engagement of the cam follower with the bottom of the notch in the cam disc, at such a point that the aforesaid anvil edge of the simple lever must pass away from engagement with the aforesaid end of the other arm of the V- shaped lever, during the imparted rotational movement of the simple lever, before the clapper strikes the bell, there being accordingly provided a region of free movement of the clapper end of the simple lever, which, after the bell has been struck, permits the immediate retraction of the clapper to a position in which it does not interfere with the resounding vibrations of the bell.

MARCUS H. RHODES. JOHN FANZOI.

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