US2389900A - Mounting for explosionproof motors - Google Patents

Description

Nov. 27, 1945. w. H. DE LANCEY MOUNTING FOR EXPLOSION PROOF MOTORS Filed Oct'. 15, 1943 Patented Nov. 27, 1945 MOUNTING FOR EXPLO SIONPROOF MOTORS Warren H. De Lancey, Springfield, Mass, assignor to Gilbert & Barker Manufacturing Company,

West Springfield, Mass.,

Massachusetts a corporation of Application October 15, 1943, Serial No. 506,438

1 Claim.

My invention relates to an improvement in dispensing pumps for gasoline and the like and more particularly to an improvement in the power drive for such pumps.

A gasoline dispensing pump is a highly integrated unit including, in a usual form, a. pump for drawing the gasoline from a supply tank, an electric motor for driving the pump, a flexible hose with a valve controlled discharge nozzle, 9. meter driven by the gasoline flow for registering the amount of gasoline dispensed and means to reset the meter after each dispensing operation.

Experience has shown that certain interlocking or interdependence in the operation of the var ious controls of the elements of the combination is desirable. Thus in one common arrangement the controls are so integrated that the operator cannot start the motor without removing the dispensing nozzle from it supporting hook; he cannot replace the nozzle on the hook until he has stopped the motor; he cannot start the motor unless he has reset the register of the meter to zero. Various other interlocks are or might be used but those mentioned are sufflcient to indicate the integrated character of the various controls. Because of the explosion hazard in the handling of gasoline it is highly desirable to use an explosion proof type of motor in which the motor parts including the motor control switch are enclosed in a tight casing and the motor i'eed wires are conducted into the casing through a rigid explosion proof conduit.

For efficient operation it is desirable that the belt tension be increased when and a the torcue increases. The rigid connection of the feed wire conduit to the motor casing and the similar fixed relation of the switch control linkage to motor casing has prevented automatic adjustment of the belt tension. Once the motor has been installed any subsequent adjustment of its position has required that both the rigid metal pipe conduit in which the motor wires are encased and the ex terior switch control linkage be disconnected and refitted to the new adjusted position of the motor.

The principal object of my invention is to provide an explosion proof power plant for gasoline pumps, using a belt transmission and providing an automatic increase in belt tension when the torque is high as at start of the dispensing operation or when the torque increases in the course 01' the dispensing operation, as occur when the dispensing nozzle is partly closed, all without interfering with the present close integration of the pump controls and the explosion proof features of the installation.

A further object is to secure the above advantages and at the same time permit the use of a temporary contact type of switch for the motor control if desired.

Other and further objects will be made apparent in the following specification and claim.

In'the accompanying drawing which illustrates one embodiment of my invention.

Fig. 1 is an end elevational view of a gasoline pump and power plant embodying my invention;

Fig. 2 is a plan view, on a larger scale of the motor and its connections;

Fig. 3 is a front elevational View of the structure shown in Fig. 2, parts being shown in section substantially on line 33 of Fig. 2;

Fig. 4 is a diagrammatic view showing the adjusting movement of the motor, and

Fig. 5 is a detail view showing the manner in which a momentary contact switch may be employed.

Referring to the drawing, Hi indicates the housing of a pump connected in the gasoline supply line H. The pump operating pulley is shown at l2 and is connected by belt 13 to the drive pulley l4 secured on the drive shaft 15 of an electric motor enclosed in an explosion proof casing l6. According to my invention I provide the casing I6 with trunnion bearings I! and I8 positioned on an axis parallel to the axis of the drive shaft l5 of the motor and offset therefrom a distance less than the radius of pulley l4. At least one of said bearings, as I8, is open ended.

A bracket 20, having outstanding arms 2| and 22, is secured to the pump housing ID by bolts 23 passing through slots 24 in the bracket, permitting vertical adjustment of the bracket. The bracket arm 2| carries a trunnion 25 engaging in trunnion bearing ll of the motor casing. Arm

22 supports a member 26, secured to the arm by machine screw 28 and provided with a trunnion 30 which engages in the trunnion bearing I8 of the motor casing. The trunnion 30 is preferably formed integral'with the member 26 and a passageway 32 extends through the trunnion 30 and the body of member 26 terminating in a. coupling 33 to which the end of the rigid conduit or pipe 34 is tightly connected. A second passageway 35 extends through the trunnion 30 and member 26, the axis of passageway 35 being parallel with the axis of the trunnion. The motor feed wires, not shown are encased in the conduit 34 and are carried through passageway 32 to the motor in an explosion proof manner. Passageway 35 forms a bearing for a shaft 36 connected at its inner end to the motor control switch, indicated at 31. The outer end of shaft 36 is rigidly connected to a lever 38 one end of which is pivotally connected to a link 39 through which the switch is remotely controlled. By the arrangement just described the motor casing It may be swung on its eccentric supporting trunnions to move the drive pulley M of the motor toward or away from the driven pulley l2 of the pump without in any way disturbing or requiring adujstment of the wire conduit v34 or the remote switch control mechanism 36-38-39 and the other control devices integrated with it. All of the adjustments needed are, as later described, made by movement of the motor about the axis of the eccentric trunnions through which all the connection to the motor pass.

The action of gravity tendst'o keep the motor in a position in which the axis of the motor shaft and the axis of the motor trunnions "I1 and 18 are in the same vertical plane. The belt is driven in the direction of the arrows in Fig. l with the driving tension in the upperrun of the belt. Since the radius of the pulley I4 is greater than the distance between the axis of the trunnions and the axis of the motor shaft, upon which pulley I4 is mounted, the driving tension in the upper run of the belt applied through the leverage of the pulley tends to swing the motor and pulley M to the right in Fig. 4 and away from pulley l2. A tension spring 40 is connected between a lug 4| formed on the motor casing and a stationary lug 42 .formed on bracket 20. Spring 40 is under an initial tension to supply the desired tension in the belt to accommodate the starting torque. Any increase in the operating torque, causing an increase in the pull on upper run of belt, acts through theleverage of the pulley to swing the motor on its trunnions to increase the distance between the pump and motor pulleys to increase the belt tension as the torque increases. Thus an automatic adjustment of the belt tension maintained without interfering with the explosion proof .features of the installation or the integration of the pump controls.

It will be .seen that my novel mounting arrange ment makes it possible to make the explosion proof installation in a standard mannerand then make the desired fixed adjustment of initial spring tension and motor position to secure the desired starting. and automatic running adjustvments. These initial adjustments can subsequently be changed if desired to meet changed operating conditions, and such adjustments and the control shaft 36. In Fig. 3 the switch 3'! is shown as a mercury .switch secured directly .to the shaft 36 and directly operated by the oscillatory movement of the shaft. In some cases it is preferable to use'a temporary contact switch, that is a switch in which the contacts are normally held apart by spring action and the circuit remains closed only so long as pressure is maintained on the switch button to overcome the spring pressure. My arrangement permits the use of such a switch as indicated at in Fig. 5. As there shown, a bracket .51 is-secured to the fixed trunnion l8. Bymounting the switchfit on a bracket thusifixedly supported the operating button 52 of the switch is maintained in fixed relation to thesha'ft 3S and may be operated, in an obvious manner, by a cam 53 "secured to the end of shaft 35. In the use of either the direct connection of switch 3'! or the cam connection of switch 50 the flexibility of the wire connections, not shown, permit the necessary relative movement of the motor with respect to the switch.

What I claim is:

A motor of the type which is mounted for pivotal movement about an axis eccentric to'its drive shaft, an explosion pr'oof'casing enclosing and carryingsaid motor, a motor switch inside the "casing, aligned bearings eccentric to the :motor shaft formed in said casing, rigid fixed 'trunnio'ns I engaging in said bearings and supporting the casing, one of .said trunni-onshaving a conduit passage from within the casing to an "endoutside the casing and adapted at the outside end to make a tight pipe-unionconnection to a rigid fixed outside wiring conduit, and one of said trunnions having an opening extending from inside-to the outside of the casing, and a rigid switch operating rodextending through suchopening from the outside to the inside of the casing making a close but slidable fit with said opening, and .affording actuation of the switch by a predetermined movement of the rod regardless of any change of position of the casing with respect to its supporting trunnions.

WARREN H. DELANCEY.

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