Convertor For Top Loading Tanks

Abstract

A convertor for mounting into an opening in the top of a gasoline tank truck at a bulk loading station to enable the tank to be filled and tank vapor to be recovered. The convertor provides a positive leak-proof connection for the filling and vapor recovery operations and is mechanically locked to the tank. A safety latch permits connection of filling and vapor recovery hoses to the convertor only after the convertor has been latched in place and permits release of the convertor from the tank only after the hoses have been removed.

Description

BACKGROUND OF THE INVENTION

At the present time there are in service many bulk loading stations with top loading racks, i.e., elevated racks under which the trucks park and which fill the trucks through manhole openings in the tops of the trucks. In these systems, when the manhole cover is displaced, a loading arm with a conical head is lowered against the rim of the opening and the head seals against the rim by gravity. The head has a fill passage and a vapor recovery passage. U.S. Pat. No. 2,803,269 discloses a typical installation of this type. This system is not considered satisfactory because a tight seal may not be made, in which case gasoline vapor from the tank can escape to atmosphere.

SUMMARY OF THE INVENTION

In accordance with this invention, a convertor is provided at the overhead rack and is inserted and mechanically locked within the manhole opening in sealed relation thereto. The convertor has a first fitting to which a coupler on a filling hose may be connected and a second fitting to which a coupler on a vapor recovery hose may be connected.

The converter includes a closure plate that makes a sealed connection with the rim of the manhole opening and is mechanically locked in position by dogs that grip the underside of the manhole ring.

In order that the seal between the closure plate and the tank may be automatically released when excessive pressure within the tank occurs, the dogs are operated by cam mechanisms which include overcomable resilient connections that permit momentary unseating of the closure plate from the tank to permit venting of the tank to atmosphere.

The dogs are provided with cam actuators having handles which in the unlocked position of the dogs prevent attachments of the filter and vapor recovery hoses to respective fittings on the convertor so that the filling operation cannot be initiated until the converter is locked into place in the manhole opening. The relationship of each handle to its associated fitting is also such that the handle cannot be moved to unlock the convertor until the hoses have been uncoupled from the fittings.

The convertor also includes a filler pipe that extends to the bottom of the tank to prevent splashing and increased static electric charge during filling.

The convertor is also provided with a level sensing device for shutting off flow into the tank when the latter is filled to the desired level.

DETAILED DESCRIPTION

FIG. 1 is a perspective partial view of a tank truck having the convertor locked thereto ready for the coupling of hoses to the convertor.

FIG. 2 is a plan view of the converter with the latch assemblies in position to prevent attachment of hoses to the convertor.

FIG. 3 is a side view of the convertor.

FIG. 4 is a transverse sectional view taken along the line 4--4 of FIG. 2 and shows the convertor applied to the tank but not locked thereto.

FIG. 5 is an enlarged fragmentary sectional view of one of the latch assemblies in an unlock position and taken along line 5--5 of FIG. 2.

The convertor is generally identified by numeral 10 and includes a closure plate 11 having its lower portion configurated for reception within manhole opening 12 in tank truck 13. Manhole opening 12 is defined by a ring 14 that includes a horizontal flange 15 having a circular sealing rib 18 projecting therefrom and a depending ring 16. A flange 17 of plate 11 seats on rib 18 to seal the converter relative to tank 13. Rib 18 may be in the form of a resilient ring to facilitate sealing. A manhole cover 20 normally seals against rib 18 when convertor 10 is not in place.

Housing 11 has a fill passage 21 formed therein and a filter of plate 11 in alignment with fill passage 21 for delivering fuel to the bottom of tank 13 to prevent splashing and increased static electric charge during filling.

Plate 11 also has a vent passage 25 therethrough for the return of vapors. A vapor recovery fitting 26 is removably secured to plate 11 in alignment with vent passage 25 by fasteners 27.

As shown in FIG. 2, fittings 22, 26 are generally diametrically oppositely disposed except that fitting 26 is slightly offset to provide space for a liquid level sensor 28.

Plate 11 carries two latch assemblies 30, 31 of identical construction in diametrically aligned relation with latch assembly 30 being associated with fitting 22 and latch assembly 31 being associated with fitting 26.

Each latch assembly 30, 31 includes a cup shaped portion 32 of plate 11 having a guide sleeve 33 therein. A latch member 34 is slidably and rotatably mounted within sleeve 33 and is sealed against vapor escape by a seal ring 35. The lower end of latch member 34 or lug 36 engageable beneath ring 16 to lock converter 10 in place.

A stop washer 37 is attached to sleeve 33 by screws 37'. A cup shaped spring retainer 38 has a lower flange 40 surrounding sleeve 33 and engaging the underside of washer 37. Coil spring 41 is seated in portion 32 and has its upper end engaging upper flange 42 of retainer 38. A thrust washer 43 seats on flange 42 and also against a shoulder 44' of a cover 44. Thrust washer 43, retainer 38 and spring 41 are clamped in place by cover 44 which is secured to portion 32 by fasteners 45. Washer 37 retains spring 41 and retainer 38 when cover 44 is removed.

Each latch assembly 30, 31 includes a handle 46 secured to a bifurcated cam 47 pivotally connected to the upper end of latch member 34 by a pin 48 and reacts against thrust washer 43. Handle 46, cam 47 and latch member 34 are rotatable as a unit about the axis of latch member 34 to swing dog 36 between an inoperative position so as to be receivable in manhole opening 12 and a latching position beneath ring 16.

When dog 36 is in the position of FIG. 5, rotation of handle 46 and cam 47 clockwise about pin 48 draws dog 36 up against ring 16 to yieldingly clamp plate 11 against rib 18 in sealed engagement therewith. The stroke of cam 47 is sufficient to force thrust washer 43 and retainer 38 downwardly away from shoulder 44', thus compressing spring 41 whereby dog 36 is in resilient pressure contact with ring 16.

Cover 44 has a circumferential slot 51 connected to a transverse slot 52. These slots function as guides for movement of handle 46. As shown in FIG. 2, in the inoperative position of latch assembly 31, handle 46 is in the respective transverse slot 51 and projects into overlying relation to fitting 26, thus preventing attachment of coupling 53 of vapor recovery hose 54 (FIG. 1) to fitting 26. In like manner, in the unlatch position of latch assembly 30, handle 46 thereof overlies fitting 22 and prevents attachment of coupler 55 of fill hose 56 to fitting 22. Thus hoses 54, 56 cannot be coupled to convertor 10 until convertor 10 is latched to tank 13.

When handles 46 are in the position of FIG. 2, dogs 36 are in a position rotated away from the position shown in FIG. 5 so as to be receivable within ring 16. After convertor housing 11 is seated on rib 18, handles 46 are in slots 51 and may be rotated in a horizontal plane to rotate latch members 34 and position dogs 36 under ring 16 as shown in FIG. 5. Then handles 46 are rotated in vertical planes in slots 52 to pivot cams 47 and pins 48 to raise dogs 36 into engagement with ring 16 and to depress washer 43 and spring 41 to resiliently lock convertor 10 to tank 13. Hoses 54, 56 may now be connected to fittings 22, 26 and the filling operation initiated.

If an attempt is made to remove convertor 10 from the tank prior to uncoupling hoses 54, 56, handles 46 when rotated in slots 52 will engage couplers 53, 55 before the handles reach slots 51 and therefore the handles cannot be rotated in slots 51 far enough for rotating dogs 36 out from beneath ring 16. Removal of convertor 10 is thus prevented until removal of hoses 54, 56 is accomplished.

Liquid level sensor 28 includes a sensor unit 54 depending from the underside of plate 11. Sensor unit 54 includes a guide sleeve 55 having float 56 therein that operates a conventional switch (not shown) in sensor 28 for shutting off an electrically controlled pump when the tank is full.

Three pins 58 attached to the lower part of convertor plate 11 protect sensor unit 54 and latch members 34 during handling of the convertor and to support the convertor when it is removed from the tank truck.

From the foregoing, it will be apparent that convertor 10 is mechanically locked to the tank and makes a positive seal relative thereto during the filling operation. However, if internal fluid pressure within the tank 13 becomes excessive it acts upwardly on plate 11 to further compress springs 41 so that even though the convertor is still latched in place by dogs 36, plate 11 lifts off of rib 18 against the action of springs 41, to provide relief valve action to vent the tank to atmosphere. Upon reduction of tank pressure, springs 41 reseat plate 11 onto rib 18 to again seal the convertor relative to the tank.

Hoses 54, 56 carried by a suitable loading arm (not shown) as desired for connection to convertor 10. Convertor 10 is normally positioned manually in the manhole, but the loading arm could also include a suitable flexible support (not shown) for convertor 10 to facilitate positioning and removal thereof from the tank truck.

Although only a preferred embodiment of a convertor has been illustrated and described, it is to be understood that minor modifications may be made in the convertor without departing from the spirit and scope of the invention, as defined by the appended claims.

Claims

We claim:

1. A convertor for use in filling a tank with liquid through an opening in the tank, the convertor including a closure plate sealingly engageable with the tank for closing said opening, latch means carried by said convertor and engageable with the tank for locking the closure plate to the tank, a fitting on said closure plate for receiving a flow line, and actuator means for said latch means movable between a release position in which the latch means interferes with the attachment of the flow line to said fitting and a lock position in which the latch means permits said attachment.

2. The convertor of claim 1 wherein said actuator means is of a construction wherein a portion of a path of movement of a part thereof is through an area occupied by the flow line when the latter is attached to said fitting, and the relation between said actuator means and said latch means is one wherein said latch means remains engaged until said acutator means moves into said area.

3. The convertor of claim 1 wherein said closure plate has at least two fittings for receiving two separate flow lines, there are at least two latch means, and each fitting has associated therewith an actuator means for a respective one of said latch means.

4. The convertor of claim 1 wherein said latch means includes a resilient member that permits unseating of said closure plate from said tank in response to excess pressure in the tank while the latch means is still in locking engagement with the tank.

5. The convertor of claim 1 wherein said latch means includes an elongated latch member having a transversely projecting latching element, means on said closure plate mounting said latch member for axial and rotary movement relative to said closure plate, and said actuating means being operable to move said latch member in a predetermined sequence to effect latching and releasing of said closure plate relative to said tank.

6. The convertor of claim 5 wherein said actuating means includes a handle connected to said latch member, and guide means carried by said closure plate and cooperable with said handle for limiting the directional movement of said handle in accordance with said sequence.

7. The convertor of claim 5 wherein said actuating means includes a cam connected to said latch member for rotation therewith and for pivoting relative thereto, a handle connected to said cam for rotating said cam and said latch member and for pivoting said cam, and guide means carried by said closure plate and cooperable with said handle for limiting the directional movement of said handle in accordance with said sequence.

8. The convertor of claim 5 wherein there is a thrust member engaged by said cam for reaction thereagainst to move said latch member axially, and resilient means carried by said closure plate supporting said thrust member for movement away from said cam whereby excessive pressure on said closure compresses said resilient means and permit said closure plate to disengage from its sealing engagement with said tank.

9. The convertor of claim 1 wherein said latch means includes an elongated latch member having a transversely projecting latching element, means on said closure plate mounting said latch member for axial movement through said closure, said actuating means including a cam connected to said latch member for pivoting relative thereto, a handle connected to said cam for pivoting said cam and effecting axial movement of said latch member, and a thrust member engaged by said cam for reaction thereagainst to move said latch member axially, and resilient means carried by said closure plate supporting said thrust member for movement away from said cam whereby excessive pressure in the tank acting on said closure plate compresses said resilient means and permits said closure plate to disengage from its sealing engagement with the tank.

10. The convertor of claim 1 wherein said convertor is particularly adapted for use in filling a fuel tank truck having a hatch opening normally closed by a displaceable cover and said closure is of a construction for temporarily sealing said hatch opening.

11. The convertor of claim 10 wherein said convertor is particularly adapted for filling the tank truck, said flow line is a filling hose, and said fitting is of the type for receiving an interlocking hose coupler.

12. The convertor of claim 11 wherein said closure plate has a second fitting for receiving a vapor return hose coupling, and there is a second latch means having second actuator means, said second actuator means cooperating with said second fitting to prevent a vapor return hose to be coupled to said second fitting until said second latch means are engaged and to prevent said second latch means to be released when said second fitting has a vapor return hose coupling attached thereto.

13. The convertor of claim 12 wherein said fittings are generally diametrically disposed on said closure plate, and said latch means are diametrically disposed intermediate said fittings.

14. The convertor of claim 12 wherein each of said latch means includes a spring that permits disengagement of said closure plate from said tank in response to excess pressure thereon from within the tank while the latch means continues to maintain the closure plate locked to the tank.

15. The convertor of claim 10 wherein said fitting has an extension projecting below said closure plate for depending into a tank being filled to prevent splashing of incoming fuel and increased static electric charge during filling.

16. The convertor of claim 10 wherein a liquid level sensor is carried by said closure plate for indicating when the tank is filled to the desired level.