US664986A - Electric switch. - Google Patents

Description

No. 664,986. Patented lan. I, |90I.

s. H. WHITTINGHAM.

ELECTRIC SWITCH.

(Application led Mar. 19, 1900.)

(No Model.)

UNITED STATES PATENT OFFICE..

GEORGE H. WHITTINGIAIAM, OF BALTIMORE, MARYLAND.

ELECTRIC SWITCH.

SPECIFICATION forming part 0f Letters Patent No. 664,986, dated January 1, 1901.

Application tiled March 19, 1900. Serial No. 9,207. KNO model.)

To all whom it may concern:

Be it known that I, GEORGE H. WHITTING- HAM, a citizen of the United States, residing at Baltimore, inthe State of Maryland, have 5 invented cert-ain new and useful Improvements in Electric Switches, of which the following is a full, clear, and exact description.

This invention relates to electric switches or cutouts, the object being to provide a 1o power-operated device which can be thrown into and out of operation by the aid of a small electric current.

The invention consists ofthe details of construction whereby a simple and efficient ap- :5 paratns is provided.

In the accompanying drawings, Figure l is a front elevation of my improved switch; and Fig. 2 is a vertical section thereof, parts being shown in elevation.

Referring to the drawings by letter, A indicates a metallic frame upon which the parts of the switch are mounted. To the front of this frame is attached a plate B, of slate or other suitable insulating lnaterial, to which the metallic portions of the switch are directly attached.

The switch illustrated is of the double-pole variety, the stationary contacts c c c2 c3 each being in the form of two metallic blades, to each pair of which the conductors u and Z) are respectively attached by the usual binding posts or screws, as shown. These contacts are arranged in pairs one above the other and on each side of the center of the board I3. Extending vertically across the face of the board is a rod E, mounted to slide in bearings e e', one of which is fixed to the face of the board and the other to the main frame A. At its extreme upper end this rod carries a weight w, which affords a continuous tendency to keep the rod in its lowermost position. There is loosely connected with this rod a frame F, consisting of two parallel uprightsff, connected together above and below by cross-pieces f and f2, of non-conductive material, said cross-pieces being pierced to allow the rod E to pass freely through them. Above the lower cross-piece the rod E is iitted with a collar g, rigidly secured thereto, and between this collar and the upper cross-piece a spring s is inserted, so that when the rod E moves upward its motion will be transmitted to the frame through the spring. The cross-pieces j" and f2 carry metallic bridgingplates h h', which project on each side and are so positioned that they will respectively pass between the blades of each pair of contacts c c and c2 c3 and make frictional engagement therewith. When in such engage-` ment, the circuit is continuous 'through the conductors a and b. The lowermost position of the frame F is determined by the bearing @,against which the frame rests, and the lowermost position of the rod E is determined by the cross-piece f2, against which the collar g rests.

Vte will now refer to the power devices for moving the rod E and to the means for connecting the power device therewith. Immediately below the rod E and in line with it is a bar I of iron, the lower portion of which is provided with rack t', which is adapted to engage a pinion t" on a shaft t2. The shaft we will assume to be constantly rotating, although not necessarily so, by a motor acting through plate and pulley The bar I passes through bearings jand y, in which it has a lateral play, the upper end resting against the lower end of the rod E and provided with an inwardly-turned flange f2, which acts in the nature of a hook, which when the bar is free engages with the frame and suspends the bar in an inclined position out of engagement with the pinion t.

In front of the bar I, suitably attached to the main frame and magnetically insulated therefrom by brass plates, is an iron-clad or cup-shaped electromagnet C, whose magnetic circuit is partially closed through the iron bar I. The center of this magnet is provided with a cavity containing a plunger@ and a spring p', normally forcing the plunger against the bar and holding it out of contact with the poles of the magnet and also out of engagement with the pinion fi.

The operation is as follows: So long as the electromagnet is denergized the bar I, rod E, and the connected parts are all in their lowermost position, as shown, the circuit being closed through lines a and b. To open the circuit, magnet C is energized by a small current. It attracts the bar I, which thus acts as an armature and throws the rack into engagement with the rotating pinion e", the

IOC

plunger p being forced inward and the bar carried into mechanical contact with the poles of the magnet. The motion transmitted from the pinion will cause the bar I to move upward and push the rod E in the same direction. The frame F will at first remain stationary while the spring 3 is being compressed; but finally the force of the spring acting against the upper cross-piece f will overcome the frictional engagement between the bridging-pieces hand h and the contacts and frame will make a quick upward movement and open the circuit through the conductors d and b without serious arcing. The bar I and the rod E will move steadily upward until the rack runs out of engagement with the pinion, whereupon the motion of the switch parts Will cease and will be held in the elevated position by the magnetic and mechanical friction between the bar I and the face of the poles of the magnet.

It will be understood that in case the motor which drives the pinion i is stopped at any point in the upward movement of the switch the magnet will retain the parts and prevent backward or independent movement.

To close the circuit, the small current through the magnet P is discontinued, whereupon the action of the spring p upon the plunger p is sufficient to overcome any sticking of the bar I against the poles of the magnet, and the mechanical and magnetic friction then ceasing the weight w carries the rod E and arm I to their lowermost or normal positions, which movement is made without mechanical engagement with the pinion t". The bridge-pieces h and h' are carried into close frictional engagement with the blades by the weight w.

It will be seen that the frictional engagement between the bar I and the faces of the poles of the magnet serves as a brake to steady the upward movement of the parts and retain them in any position in which they may be left by the power devices.

Having described my invention, I claim- 1. In a power-operated switch, the combination of a movable switch element, a source of power for moving the same and an electrolnagnet serving to couple'said switch element and source of power together and to retain the switch element in any position to which it may have been moved by the source of power.

2. In a power-operated switch, the combination of a movable switch element, a reciprocating rod adapted to engage and move the switch element7 a source of power for moving said rod, and an electromagnet serving to hold the rod at any position to which it may have been moved by the source of power.

3. In an electric switch, a rod adapted to reciprocate, circuit-controlling contacts operated by said rod, a separate bar arranged in line with the rod, power devices for moving said bar to thereby move the rod and an electromagnet whose pole-pieces make sliding contact with said bar, substantially as described.

4. In a power-operated switch, the combination of a vertical rod, a frame through which the rod freely passes, contacts controlled by said frame, a spring interposed between the frame and rod, a bar arranged to push against the end of the rod a rack on said bar, a pinion for engagement with the rack, and an electromagnet adapted to throw the rack and pinion into engagement and to act as an electromagnetic friction-brake to retain the bar in position.

In witness whereof I subscribe my signature in presence of two witnesses.

GEORGE H. WHITTINGIIAM.

Witnesses:

WM. A. ROSENBAUM, J AMES A. DONNELLY.

Images