US3471660A - Electric switch for moving cables with spring-wire trip rod and contacts - Google Patents

Description

Oct. 7, 1969 Ffc. PETERS 3 7 ELECTRIC SWITCH FOR MOVING CABLES WITH SPRING-WIRE TRIP ROD AND CONTACTS Filed Feb. 16, 1968 INVENTOR l8 l7 Ham/ck Qaer/rcr 3 75a;

22 A @f/M ATTORNEY United States Patent 3,471,660 ELECTRIC SWITCH FOR MOVING CABLES WITH SPRING-WIRE TRIP ROD AND CONTACTS Frederick C. Peters, 2234 Moodie St., Fort William, Ontario, Canada Filed Feb. 16, 1968, Ser. No. 706,127 Int. Cl. B65h 25/14; H01h 3/16, 3/00 US. Cl. 20061.13 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates to new and useful improvements in switches for moving cable operated devices.

Although it is designed primarily for use with ski lift equipment, nevertheless it will be appreciated that it can be utilized in any device which uses a moving cable for operating same.

In ski lifts or T-bar lifts, or the like, it is required by law to have some form of controller adjacent each tower and usually on both the upper and lower runs of the cable so that any movement of the cable beyond a predetermined amount will trip the switch and cause the device to cease operating immediately.

For example, if a cable becomes disengaged from the sheave at a tower, then it is essential that the switch be operated immediately.

Conventional switches include magnetic field operated switches or microswitches both of which sulfer from several disadvantages.

The magnetic field type of switch is provided with no flexibility of operation due to the fact that the magnetic field is utilized to operate same. It is therefore usual to incorporate a time delay to prevent minor deflections of the cable from operating the switch.

Microswitches are diflicult to maintain and operate in relatively cold weather and are dilficult to service when on towers which are situated remotely from the operating center of the ski lift or tow rope.

It is desirable that a switch be provided which can be adjusted as to the sensitivity of operation and which furthermore can take a considerable amount of mechanical abuse Without being damaged.

It is also an essential feature of the switch that it does not reset automatically but has to be manually set before the cable will again operate.

The present switch satisfies these requirements inasmuch as it is made from spring steel wire, can be adjusted readily, can be used above or below a cable, and furthermore can be operated by a turned over T-bar or the like without damage occurring to the switch.

Furthermore the present switch is economical in manufacture, simple in installation and operation, and otherwise well suited to the purpose for which it is designed.

With the foregoing considerations in view, and such other objects, purposes or advantages as may become apparent from consideration of this disclosure and specification, the present invention consists of the inventive concept exhibited in the method, process, construction, arrangement of parts, or new use of any of the foregoing herein particularly exemplified in one or more specific embodiments of such concept, reference being had to the accompanying figures in which:

FIGURE 1 is a partial isometric view of the invention per se.

FIGURE 2 is a fragmentary end view of the movable and fixed contacts together with the indicating rod.

FIGURE 3 is a partially schematic side view showing the relationship of the device to one of the sheave pulleys.

FIGURE 4 is a schematic view showing one method of electrical connections between the motor, the switch, and the indicating device.

In the drawings like characters of reference indicate corresponding parts in the different figures.

Proceeding therefore to describe the invention in detail, reference should first be made to FIGURE 1 in which 10 illustrates a strap having an attaching clamp arrangement 11 at one end thereof within an elongated slot 12. This enables the strap to be secured to the tower 13 in a convenient position so that the switch can be located with reference to the cable 14 as desired.

In FIGURE 3, the strap 10 is shown secured to one of the bolts 15 normally holding the bearing for the sheave 16.

On the distal end 17 of the strap, is a further clamping member 18 which clamps the two legs 19 and 20 of the trip rod collectively designated 21. This trip rod includes the substantially vertical anchoring portion 19 which is clamped by the aforementioned clamp 18 and then extends upwardly by means of the U shaped base 22, through an insulator 23 and thence to the anchor portion 19 to which it is spot welded as at 24 for stability.

Formed on the upper end 25 of the anchoring portion 19 is a plurality of coils 26 which terminate in the horizontally extending portion 27, said anchor portion 19, coils 26 and extending portion 27 being made preferably, from resilient spring steel so that the coiled portion 26 permits resilient movement of the extending portion 27 in all directions.

The anchoring portion 19 extends through an insulator and support 28 as clearly shown and also extending through this insulator and support 28 is a fixed control contactor rod 29 which extends upwardly substantially parallel to the anchoring portion 19.

The lower end 30 of this rod 29 is connected to a relatively low voltage source of power indicated in FIG- URE 4 by reference character 31.

Situated on the extending portion 27 of the trip rod 21 and between the distal end 32 and the spring portion 26, is an insulator and support 33, the portion 27 extending through this insulator and support as clearly shown.

Also extending through this insulator and support 33 is a movable control contactor rod 34 which is situated substantially parallel to the extending portion 27 but extends rearwardly over the spring portion 26 and normally engages the upper end 35 of the fixed control contactor rod 29, the resiliency of the coils 26 biasing the rod 34 in contact with rod 35 as shown in FIG. 2.

This movable control contactor rod 34 is also connected to the power source 31 through a solenoid 36. The solenoid, when the circuit is complete as shown in FIGURES 1 and 4, normally pulls the switch 37 into engagement thus connecting the line power with the motor 38 operating the moving cables.

In FIGURE 1, reference character 13 shows the position of the trip rod with relation to the cable 14. If the cable 14 becomes disengaged from the sheave 16 it will drop and strike the trip rod 27 forcing end 32 downwardly which automatically moves the inner end 39 of the movable control contactor 34 upwardly, both portions pivotting around the axis of the spring portion 26. This enables the inner end 39 to clear the upper end 35 of the fixed control contactor rod 29 whereupon the resiliency of the spring portion 26 moves it rightwardly 3 with respect to FIG. 2 so that it takes up the position shown in phantom and against an indicator rod 40 which will hereinafter be described.

As soon as the inner end 39 of rod 34 clears the upper end 35 of rod 29, the circuit of the solenoid 36 is broken so that the switch 37 is disengaged thus breaking the main circuit to motor 38 and stopping the cable immediately. This cable cannot be restarted until the switch is manually reset after the fault causing the switch to operate, has been corrected. The trip rod has to moved downwardly so that the inner end 39 clears the upper end 35 of rod 29 whereupon it has to be moved sideways against the tension of the spring 26 and then the end 32 is moved upwardly so that the inner end 39 once again engages the rod 29 as shown in FIGS. 1 and 2.

It is sometimes desirable that an indicator be supplied adjacent the operating center for the cable device, so that the operator can ascertain exactly Where the fault has occurred.

In this connection I have provided a substantially vertically situated indicator rod 40 supported in the aforementioned insulator and support component 23 and extending substantially parallel to the fixed control contactor rod 29 but spaced herefrom.

This rod 40 is connected by cable 41 to one side of the source of electrical power 31 through an indicating meter 42.

As soon as the switch is operated by cable 14, it contacts the indicator rod 40 and completes the circuit through the indicator rod to the meter 42 and by varying resistors 43, the indicating meter 42 can be designed to indicate exactly which switch has been disengaged thus localizing the fault.

The device can, of course, be reversed so that the trip rod 27 is above cable 14. The device can also be operated by a T-bar which has become twisted or otherwise hung up on the cable as a side swiping effect to the extending end 37 will also cause the switch to disengage, the resiliency of the entire structure preventing damage from occurring to the switch mechanism.

Various modifications can be made within the scope of the inventive concept disclosed. Accordingly, it is intended that What is described herein should be regarded as illustrative of such concept and not for the purpose of limiting protection to any particular embodiment thereof, but that only such limitations should be placed upon the scope of protection to which the inventor hereof is entitled, as justice dictates.

What is claimed to be the present invention is:

1. In an electric switch of the character described, the combination of a spring-wire trip rod including a substantially vertical fixed mounting portion and a substantially horizontal feeler portion provided at the upper end of said mounting portion, said feeler portion being -Inovable in vertical and horizontal planes, a substantially horizontal contact arm secured to and movable with said feeler portion, insulating block means provided on said mounting portion, and first and second contact rods supported in horizontally spaced apart relation by said block means and extending upwardly therefrom with the second contact rod projecting above said contact arm to a greater extent than the first contact rod, said contact ar-m being normally biased by said spring-Wire trip arm against a side of said first contact rod opposite from the second contact rod, but being movable vertically past the first contact rod and horizontally against said second contact rod when said feeler portion of the trip rod is vertically deflected.

2. The switch as defined in claim 1 wherein said spring-wire trip rod also includes a coil portion connecting said mounting portion and said feeler portion together, said feeler portion extending from said coil portion to one side of the mounting portion, and said contact arm on the feeler portion extending past the coil portion to the opposite side of the mounting portion where said first and second contact rods are disposed.

References Cited UNITED STATES PATENTS 2,196,784 4/ 1940 Simmons et a1. 200--61.l3 X 2,689,890 9/1954 Green 20061.13 2,943,158 6/ 1960 Dubeau.

3,132,466 5/1964 Preisser 200-61.18 X 3,180,950 4/ 1965 Jacobsen ZOO-61.41 3,254,167 5/1966 Altmann ZOO-61.13 2,912,543 11/1959 Hawkins.

FOREIGN PATENTS 1,137,511 10/1962 Germany.

ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant Examiner US. 01. X.R. 1200-6141; 166

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