Fluid Dispensing Apparatus

Abstract

A gasoline pump is provided with a lost motion cam and a compressible linkage operating between the cam and the pump motor control microswitch so that the shaft carrying the cam must reach a predetermined operative position before the switch is closed. This prevents malfunctioning of the system. It also protects the microswitch from damage and allows for positive operation of the microswitch by permitting the cam to have a very much larger throw than is required to operate the microswitch.

Description

BACKGROUND OF THE INVENTION

Fluid dispensing systems, and particularly gasoline pumps, may be provided with certain interlocking mechanisms for assuring proper functioning of the system. More specifically, gasoline pumps utilize indicating registering mechanisms which indicate the quantity of fluid pumped and the price, as is well known. It is required that the mechanism be reset at the end of the dispensing operation and conventional and well known interlock means are utilized to effect this function. Among other things, it is desirable that the shaft which completes the interlocking function be utilized also to operate a switch controlling the pump drive motor but it is also desirable that this shaft be positively moved to a predetermined position before the pump drive is energized, thus preventing malfunctioning of the system in which the quantity of fluid pumped would not be registered upon the indicating mechanism.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to certain improvements in dispensing systems as described hereinabove wherein the shaft for preparing the system for a pumping or dispensing cycle carries a cam operating, through a linkage, a microswitch for controlling the pump drive motor. The cam is connected through lost motion mechanism to the shaft so that the shaft must reach a predetermined operative position before the linkage is permitted to actuate the microswitch to closed position. Another aspect of the present invention involves the aforesaid lost motion cam mechanism in conjunction with an expansible-compressible linkage operating between the cam and the microswitch to allow the cam to have a gross movement very much greater than the movement required to operate the microswitch, thus effecting a positive switch actuation and preventing the necessity for fine and accurate adjustment of the linkage to properly control the microswitch.

Another aspect of the present invention involves the utilization of a compressible-expansible linkage mechanism in the aforesaid environment for the purpose of protecting a microswitch from damage while still allowing positive actuation of such microswitch through the utilization of a cam mechanism having a gross movement or total throw which is very much greater than the movement required to effect actuation of the microswitch between its open and closed positions.

BRIEF DESCRIPTION OF THE DRAWING FIGS.

FIG. 1 is a front elevational view partly broken away of a gasoline pump employing the construction according to the present invention;

FIG. 2 is a fragmentary side elevational view showing certain details of the cycle control mechanism;

FIG. 3 is an enlarged perspective view showing the lost motion cam mechanism;

FIG. 4 is an elevational view partly broken away showing the normal disposition of the cam and linkage assembly;

FIG. 5 is a view similar to FIG. 4 but showing the initial disposition of the cam with respect to the shaft when the latter has been moved to its operative position; and

FIG. 6 is a view showing the terminal position of the cam as imparted by the linkage assembly.

DETAILED DESCRIPTION OF THE INVENTION

With reference at this time more particularly to FIG. 1, a substantially conventional gasoline pump as indicated therein generally by the reference character 10 and includes the usual pump housing 12 within which is located the operative mechanism of the system, inclusive of a pump 13 and a drive mechanism 15 for selectively operating the pump to dispense gasoline through the usual hose 17 and nozzle 19. In addition to the above, the pump assembly 10 includes an indicating and registering panel indicated generally by the reference character 14 and which has associated therewith suitable counting mechanism located behind the window 16 to indicate the gallonage dispensed and, behind the window 18 counting mechanism to indicate the cost of the gasoline dispensed during the cycle. Additionally, as is conventional, the window 20 may be provided to indicate the price of the gasoline per gallon inclusive of the tax.

The mechanism and system involved is of generally conventional function inasmuch as on the exterior right hand side of the assembly as shown in FIG. 2 there is provided a reset lever 21 and associated shaft 23 for actuating mechanism operative to reset the counters behind the windows 16 and 18 to zero, the actuation of which lever 21 initiates the cycle or chain of operations allowing the next subsequent dispensing operation to occur. The next step in the cycle of operations is to remove the nozzle 19 from the receptacle 22 provided in the side of the housing 12 and the last operation to be performed is to throw the external lever 24 from the upright position shown to a position wherein it overlies the opening leading to the receptacle 22. The lever 24 is connected to and rotates a shaft 26 which is connected through mechanism (not shown), to complete the operative connection for actuating the indicating mechanism 14 when the pump nozzle is subsequently operated by the attendant to dispense gasoline into the associated vehicle. Thus, the shaft 26 must attain a predetermined operative position in order to cause the indicating mechanism 14 to operate. At the same time, as is conventional, the shaft 26 is utilized to operate a switch mechanism which completes the circuitry to the pump drive motor and thus allows the dispensing operation to be effected.

From the above description, it will be apparent that in order to prevent malfunctioning of the system, the switch controlling the pump drive motor should not be actuated to closed condition until after the shaft 26 has reached the aforesaid predetermined position at which it completes the operative connection to the indicating mechanism 14 else it would be possible to dispense gasoline without operating the indicating mechanism 14.

As may be seen clearly in FIGS. 3 and 4, the shaft 26 carries a cam 28 which operates through resiliently expandable-compressible linkage assembly indicated generally by the reference character 30 to control a microswitch 31 contained within a housing indicated by the reference character 32. The shaft also carries a plate member 34 having an arcuate slot 36 therein and the housing 12 carries a stop pin 38 received in the slot 36 to limit the rotational motion of the shaft 26 as imparted by the lever 24 to two extreme positions, a first inoperative position and a second operative position corresponding to the aforementioned predetermined position of the shaft 26 which completes the operative drive engagement to the indicating mechanism 14.

In FIG. 4, the cam 28 will be seen to have a heel portion 40, a toe portion 42 and a relatively steep ramp 44 interconnecting the heel and toe portions 40 and 42. In the position of the shaft 26 shown in FIG. 4, the lever 24 is in the inoperative or upright position, that is the position in which dispensing may not occur. After reset, and in order to allow dispensing, the shaft 26 is rotated to the aforesaid predetermined position by operating the lever 24 to rotate the shaft in counterclockwise direction as viewed in FIG. 4. The cam is provided with an opening 46 within which a pin or blade 48 connected to the shaft 26 is adapted to move, with the cam otherwise being freely rotatable on the shaft 26 so that the blade operating in the opening effects a lost motion connection between the shaft 26 and cam 28. From FIGS. 4 and 5, it will be apparent that as the lever 24 is first moved towards the shaft position allowing proper operation of the dispensing system, the pin 48 will at first travel with lost motion with respect to the cam in the opening 46 thereof until it reaches the dashed line position shown in FIG. 4 whereafter continued rotation of the shaft 26 will rotate the am in unison with the shaft. The toe 42 of the cam extends to a position as indicated by the reference character 50 such that the cam follower 52 of the linkage assembly 30 does not engage such portion 50 until the shaft 26 has fully or at least substantially fully reached the aforementioned predetermined position. As soon as the shaft is in its predetermined position and the cam follower 52 has reached the point 50 as shown in FIG. 5, the relatively steep ramp 44 will allow the part to assume the position shown in FIG. 6 by virtue of the spring force exerted on the cam by the linkage assembly 30. At some time during the expansion of the link assemblage 30, the pump drive motor control switch will be actuated from open position to closed position, thus energizing the pump motor 15. As is shown in FIGS. 4 and 6, the upper plunger 54 of the linkage assembly normally engages the plunger 56 of a microswitch assembly for controlling the pump motor so as to urge the switch to open position and when the linkage 30 is in the expanded condition as is shown in FIG. 6, the switch plunger is allowed to move to its projected position in which the pump drive motor switch is closed.

The linkage assembly 30 comprises, in addition to the aforementioned upper plunger 54, a lower plunger 58 carrying the aforementioned cam follower 52 and which plunger 58 projects upwardly within a housing 60 which also receives the upper plunger 54, substantially as is shown. The inner ends 62 and 64 of the two plungers 54 and 58 are disposed in relatively distantly spaced relationship and the two plungers are interconnected by means of a spring 66 seating respectively upon the circlips 68 and 70 secured to the upper and lower plungers 54 and 58 normally to urge these members away from each other. Operating between the mounting nipple portion 72 for the housing 60 and the circlip 68 is a compression spring 74 which urges the upper plunger 54 in a direction away from the switch plunger 56 when the lower plunger 58 is allowed to move the position shown in FIG. 4 to the position shown in FIG. 6. As will be readily apparent, the spring action of the linkage assembly 30 causes, as is shown in FIG. 5 and 6, the cam to rotate with respect to the shaft 26 which effects, during this process, the closing of the microswitch to control the pump drive motor.

The mechanism thus assures that the shaft 26 is in the proper position before the pump drive motor is energized and by virtue of the large movement imparted by the cam it also allows the microswitch to be positively actuated without requiring precise adjustment of the linkage 30. At the same time, because of the compressible-expansible nature of the linkage 30, the great disparity in the gross throw of the cam mechanism 28 as compared to the relatively slight movement required to actuate the plunger 56 of the microswitch does not cause damage to the microswitch.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as other inherent therein. While a presently illustrative embodiment of the invention is given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention and the scope of the appended claims.

Claims

What I claim is:

1. In a fluid dispensing system of the type including a pump; drive means for operating the pump to perform sequential dispensing operations; resettable mechanism for indicating the quantity of fluid dispensed during each operation and including control means for operating such mechanism; said control means including a shaft adapted to be rotated from a first position in which said mechanism is inoperative to a second position readying said mechanism for operation; a switch for energizing said shaft through a lost motion connection, such connection serving to move the cam only during the terminal movement of said shaft from its first to its second position; and linkage connecting said switch and said cam so that the switch will be actuated substantially simultaneously with said readying of said mechanism by movement of said shaft fully to said second position thereof; said linkage comprising two axially aligned plungers slidably mounted for axial movement the fist said plunger being operatively connected at one end to said switch, a spring urging said first plunger toward the second plunger; a second spring engaging the adjacent ends of said plungers and urging them apart, and a cam follower connected with the other end of said second plunger and riding on the cam said cam being so shaped and of such a size as to impart to said linkage a movement substantially greater than the movement of the switch between fully open and closed positions, said switch including a plunger operatively engaging the first end of said first plunger, said cam being loosely mounted on said shaft for free movement thereabout and including an opening in the form of a circular sector extending outwardly from said shaft, and a blade rigidly secured to said shaft and extending radially outward within said opening, said blade alternatively engaging opposite sides of the opening as the shaft is turned in opposite direction, said blade and slot serving to provide the aforesaid lost motion connection between the cam and the shaft.