US2859392A

US2859392A - Time delay device

Info

Publication number: US2859392A
Application number: US471572A
Authority: US
Inventors: Anthony Van Ryan; Date Kazuo Henry
Original assignee: McGraw Edison Co
Current assignee: McGraw Edison Co
Priority date: 1953-09-25
Filing date: 1954-11-29
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

Nov. 4, 1958 A. VAN RYAN EI'AL' 2,359,392

TIME DELAY DEVICE 2 Sheets-Sheet 1 Original Filed Sept. 25, 1955 IHVEHTORS ANTHONY- VAn RYAN KA-Luo Hanna DATE. BY

QM Kid- ATTORNEY 2 Sheets-Sheet 2 A. VAN RYAN EIAL TIME DELAY DEVICE Original Filed Sept; 25, 1953 7 Nov. 4, 1958 V M Ms TTORNLY United States Patent McGraw-Edison Company, a corporation of Delaware Original application September 25, 1953, Serial No. 382,365, now Patent No. 2,810,038, dated October 15, 1957. Divided and this application November 29, 1954, Serial No. 471,572

2 Claims. (Cl. 317-178) This invention relates to time delay devices for circuit interrupters.

This application is a division of our copending application Serial No. 382,365, filed September 25, 1953, now Patent No. 2,810,038, for Circuit Interrupter assigned to the same assignee as the present application.

In circuit interrupters, time delay devices are employed to secure delay in the operation of the circuit interrupter under various conditions. Among others is the two time current type of circuit interrupter in which the circuit interrupter responds to the overload either substantially instantly or after a delay period as described in greater detail in our above noted copending application.

Objects of this invention are to provide a novel form of time delay device which circuit interrupters and which may be instantly changed from a quick response device to a delayed response device so as to secure the two time current characteristics of a circuit interrupter.

Further objects are to provide time delay devices in which the response of the device may be changed from a quick response to a delayed response by control means actuated in any suitable manner as for example, through the agency of counting means as set forth in greater detail in our above noted application and in which this control means is located externally of the time delay device.

Further objects are to provide a time delay device which is so made that it may be adjusted for an inverse relation to the magnitude of the overload or may be adjusted so as to have a definite or predetermined force exerted on the time delay device whose value is independent of the value of the energizing current for operating the time delay device.

Further objects are to provide a time delay device is arranged to be adjusted to cause tripping to occur at any desired point during the tripping stroke of the time delay device so as to secure a very gradual and accurate and fine adjustment to determine the exact value of the time delay before tripping will occur.

Further objects are to provide a time delay device which is so made that means are provided for locking the parts in their several positions of adjustment.

Embodiments of the invention are shown in the accompanying drawings in which:

Figure 1 is a sectional view of one form of the time delay device and the tripping means.

Figure 2 shows a modified form of time delay device.

Figure 3 shows the modified form of Figure 2 in another position of adjustment.

Referring to the drawings it will be seen that the first form of the time delay device is shown in Figure 1 and it consists of an electromagnet having its body portion indicated generally by the reference character 10. This body portion surrounds the magnet coil 11 and a movable sleeve-like magnetic plunger 12 is slidable into the coil may be easily applied to n which is adapted to operate a tripping device and which 11 when such coil is energized. A rod 13 extends downwardly through the magnetic plunger 12 but is not attached to the plunger. A spring 14 is positioned within the upper portion of the plunger 12 and is positioned between the nut 15 screwed on the upper end of the magnetic plunger 12 and a shoulder or collar 16 formed on the rod 13. It is thus apparent that when the plunger 12 is drawn downwardly towards the stationary lower pole piece 17 that it will compress the spring 14 and urge the rod 13 downwardly.

The lower end of the rod 13 is rigidly connected with the time delay piston 18 which is slidable within its cylinder indicated at 19 which cylinder is a unitary part of the body portion of the time delay device or trip unit. The upper end of the cylinder 19 is normally in communication with the lower end of the cylinder by means of the

ducts

20 and 21 and the hollow sleeve-like member 22 whose lower end constitutes a valve seat for the upwardly spring pressed valve 23, the spring being indicated at 2-4. Normally, the valve 23 is held in the open position for the fast shots but is allowed to rise and seat against the lower end of the sleeve 22 and thus stop communication between the ports or

passages

20 and 21. When this occurs the piston 18 is delayed as the upwardly closing valve 25 has closed the opening 26 in the lower end of the piston 18. This disk or valve 25 is provided with a small hole 27 which allows fluid to flow through the piston to the upper portion of the cylinder 19 when the piston is depressed, and when the valve 23 is closed.

The magnetic plunger 12 is urged upwardly by means of the spring 28. The stress or compression of the spring 28 may be adjusted by means of the nut 29 to determine the point of overload or current value at which the plunger 12 will move downwardly.

The upper end of the rod 13 is threaded and receives the spool-like member 30 which operates the lever 31 carried by the rockshaft 32. The rockshaft 32 rigidly carries a semicylindrical latch member 33 which normally restrains the upper end of a trip finger 34 of latch means or releasing means which is described in detail in the above identified application. The position of the spool-like member 30 on the rod 13 will determine the amount of overlap between the finger 34 and its coacting semicylindrical member 33 and will thus determine the point during the downward travel of the magnetic plunger 12 at which release of the finger or lever 34 will occur. The rockshaft 32 thus controls the tripping of the main switches as described in the above identified application.

It is to be noted also from Figure 1 that the valve 23 is controlled by the rod 35 which in turn is controlled by means of a cam 36 operatively carried on a rockshaft 37. The cam 36 bears against the lever 38 which controls the postion of the rod 35 and consequently of the valve 23. The cam 36 is not directly connected to the rockshaft 37 but is connected directly to a small lever 39, rigid with the rockshaft, by means of a pin 40 which may be selectively positioned in any one of a plurality of holes 41 formed in the cam 36. The purpose of this is to provide an adjustment between the cam 36 and the lever 39 to determine the relative number of fast and slow operations of the time delay device which may be used for any purpose, but which, in the prior application, hereinabove identified constitutes a ground trip for tripping the main switches. The lever 39 which is rigid with the rockshaft 37 of the cam 36 is connected to the sequence bar 42 so that the position of the cam 36 is determined by the position of the sequence bar.

It is to be noted that the spool-like member 30 is provided with a plurality of slots 43 into any one of which a locking pin 44 may extend to thus lock the spool-like ember 30 in its adjusted position on the rod 13.

Patented Nov. 4, 1958 3 V It is to be noted that the relative position of the semicylindrical latch 33 and the trip lever 34 may be adjusted by screwing the sleeve-like member 30 upwardly or downwardly on the rod: 13 on which it isscrewed; The pin;44

is of course withdrawn during this adjustment and is: rein! Y serted after the adjustment has-been made.

As the'force due to the downward pull of themagnetic I plunger 12 is transmitted through-the spring .14 it is apparent that as soon as the-currentethroughthetcoil 11 reaches a predetermined-value that theplunger will-exea cute its full stroke and fully compress the spring 14. The spring 14 will thus urge the plunger downwardly with a definite or predetermined force independently of the-.- valueof the energizing current through. the coil 11. The

It is clear also that no matterhow heavy a current flows through the'coil 11 no' damage will be caused the tripping device since the 'force of the downwardstroke of the plunger 12'is transmitted through the spring 14 to the trip or latch meansand the force thus transmitted cannot exceed a predetermined amount. Further the adjustmentof the nut 29 determines the value of the current flowing through the coilll at which downstroke of the magnetic plunger 12 occurs. These two adjustments'rnay be made independently of each other.

In the second form of the invention shown in Figures 2 and 3, the rod 13, which corresponds to the rod 13 of In Figures 2 and 3, it will be noted, that the spool=like member 51 may be adjusted on the member'50 to any desired position and temporarilylocked in such positionby means-of the spring finger'54'carried by the member-5t). ':It is clean that if desired; numbers may be provided on the portion'49 =o'f the spool-like member 51 to indicate 'i-ts position of adjustment." Such numbers are not :shown-'on the drawing:

In theforrn or the invention -shown'in- Figures 2 and 3,

the rod 13 rigidly carries'asrnall washer 45. The washer 45 therefore constitutes a second shoulder on the rod 13'. The rod lfiflal'so'slida-bly' carries a-nut 46 which may be screwed onto the'ithreaded'lupper portion 47 of the magnetic'plunger'dT; Under-these conditions downward motion of the plunger 12', see-Figure 2, will cause the piston=l8, 'see Figure 1, to move downwardly without the intervention of the spring 14 and'consequently'the trippingmeans'or time delay means will operate inversely with reference to the current flowing through its energizing coil. .I-Iowever, when it is desired to have 'the'trip ping meansor time delay means, in its modified form shown in Figures 2 and 3 operate in'thesamemanner as the tripping means or time delay means shown in Figure 4 1, the nut 46 is unscrewed and isslipped upwardly along the rod 13, until the spring fingers 48 yieldingly grip the nut 46 as shown in Figure 3.

It is to be noted also that the relative position of the semicylindrical latch 33 and the link-34 of the latch means may be adjusted by screwing the. nut 49 upwardly or downwardly on themember 50, two different adjustments being shown in Figures 2 and 3.

it will be seen that novel time .delay.or trip meanshas been providedwhich may operate in a definitemanner" or with a predetermined force independently of the value of the overload.

It will also be seen that the time delay device maybe instantly changed so that it operates inverselyv as the-value of the overload increases.

Further, it is to be notedthat'in either form of time delay device, the device may be quickly changed, froma slow actingto a' quick acting time' delay device','-or vice' versa, and that this changeover is efiected by eXternaL" ly located controlrmeans Although this inventionhas been described in considen' able. detailyitis to be understood that such-description is intended as illustrative :rather than-limiting, as the invention may .be variously. embodied-and; is to be interpreted as claimed;

We claim:v

1. A time delay devicerfori a circuitinterruptercom prising a body portion having a cylinder: formed thereinadapted to contain.a-fluid, -a piston in said cylinder-{a piston rod,.said device having an escape opening, a magnetic plungerslidable on said rod, 1a.coilsurrounding-saidplunger, a first memberzuremovably .carriedi-by said plunger, a second member carried by said rod, a spring interposed between =said.first member andsaid second- 1 member whereby a definite force is transmitted to said piston irrespective of the magnitude of the current flow ing through'said coil, and means includingsaid first mem her for selectively locking said plunger to saidrod whereby an inverse time current relation is secured,-or for 'releasing said plunger from direct connection to said rod.-'-'

2. A time delaydevice for a circuitinterrupter-comprising a,body portion having. a cylinder formed therein adapted to contain a fluid, a piston in said. cylinder, a

piston rod projecting from said body portion, a magnetic plunger slidably carried by said piston rod, a coil surrounding .said plunger, said plunger having. a recessed outer'end. provided with an annular inwardly projecting shoulder, said piston rod having a collar located within the recessed portion of said plunger, 'a' spring interposed between .the annularshoulder of said .plunger and the collar of said piston rod, said piston rod having a second A collar located outwardly of the annularshoulder of said plunger and rigidly attached to said piston rod, and a nut removably screwed on the outer end of said plunger-to selectively clamp .the second collar of said piston rod to said plunger when said nut is screwed on said plunger. 7

or to release the second collar of saidpiston. rod from said plunger when said nut is unscrewed from :said plunger.

ReferencesCited in the file of this patent UNITED STATES PATENTS 1,452,178 Ballew Apr. '17, 1923 2,103,378 Oestnaes Dec. 28, 1937'" 2,333,604 Wallace Nov. 2, 1943