CA1037906A

CA1037906A - Safety closure cap with retaining feet

Info

Publication number: CA1037906A
Application number: CA217,967A
Authority: CA
Inventors: Alfred Cooper
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-01-17
Filing date: 1975-01-15
Publication date: 1978-09-05
Also published as: JPS50101719A; FR2258315A1; GB1467112A; JPS5832107B2; US3913783A; DE2500852C2; IT1026351B; DE2500852A1; FR2258315B1

Abstract

Abstract of the Disclosure A safety closure cap for bayonet connection with a filler spout has blocking prongs extending downwardly from and rigid with latching lugs on the cap to insure proper seating of the cap on the rim of the spout when it is placed on the spout to latch it, in combination with circumferentially arranged retaining feet to prevent gas pressure built up in the tank from blowing the cap away from the spout as it is being unlatched.

Description

~3q9Q'~ :
'` I :~
.
Back~round of th~ Inventlon A common type of closure cap for a ~iller spout on.
automobile gasoline tan~s is adapted for bayonet connection ~:
wit~ such spout. The spout comprises a top proYided with ~ .
rim ha~ing diametrically opposite ~emale notch2s therein through which latching lugs on the cap are insertable ta provide a bayonst type connection upon turning o~ the cap ~n ~ :.
one direction over the top. Opposite cam surfaces are provided ~
over which the latching lugs can rlde. Each of these sur~ac~s ~ ~, extends from and slopes downwardly ~rom ad~acent the end. o~ a notch and terminates ad~acent a down~ardly extending stopt A
sprlng pressed sealing disc structure.is secured to the :
underside of the cap top to seal against the spout rim upon twisting or turning c~ the cap in said one direction, provided: :
the latching lugs are inserted properly through the notches.
. . ' .~ ' ' ~ ,',' '' . . .
-. , . '~
--; . , ' . ' ' " . '.

.. ,, . .. . . .. ~ - ,, . . :, ~ .

379~
~ As ls di~closed ln appllcant~s U.S. patent No.

2 3,784,047, dated Janu~ry 8, 1974~ ror "SAE'ETY CLOSU~3 CAP",

3 gasollne statlon attendants are sometimes careless ln applying

4 the closure cap to the spout after a tank has been servlced with gasoline because sometimes only one latchlng lug is inserted into a *emale bayonet notch with the other latching lug merely resting on the top of` the spout. Latching is thu~
8 effected by only one lug and the cap becomes seated with a tilt so that gasoline can escape from the spout, especially- when the vehicle is accelerated. This problem is overcome, as is 11 disclosed and claimed in the a~orementioned patent, by the 12 1 provision of means in the form of blocking prongs which extend 13 ¦ downwardly from the latching lugs to insure that the cap 14 ¦ becomes properly seated on the top of the spout before it can 15 ¦ be turned to latch the same.
16 1 In prior closure cap constructions, vapor from the ¦ gasoline in the tank was allowed to vent lnto the atmosphere.
181 However, w~th the recent advent of modern emisslon control 19 system requ.rements, the tank on new model automobiles i~
maintained at a positive pressure to drive the vapor to the -21 carburetor, to be consumed by the engine. m is is und2sirable `
22 because the cap must be unlatched witA pressure applied to -23 it; and if the cap does not have a safety ~eature to retain it 24 during the unlatching, it could sometimes become propelled dangerously by sudden rellef of the gas pressure, and cause 26 inJury to a per~on unlatching the same. This is overcome ln 27 the construction of caps for late model automobile gasollne 28 tanks by the pr~vision of diametrically opposlte r_talnin~ lug~

;^: - 2 _ ::- .,. , . . , :... ., . . .. . .
: -. . - . - , :

:-. . - , . . .
: . . . . -;
. - . . .

¦1 orLset from and po~itlon~d a sub~tantlal d:Lst~nce belo~ th~
~ I latchlnz lug3 to engage the bottom o~ cam surface~ on the spout~
3 ¦ to prevent the gas pressure from blowing the cap away from the 4 ¦ spout as it ls being unlatched.
S ¦ Wlth such construction, lt is nec2ssary in latchir~
6 ¦ th~ cap to place it evenly o~er the top of the spout b~
7 ¦ insertln~ the retaining lugs through the ~pout notches, tu~n ~t 81 partially in the direction to latch the same to allow the of~se~
¦ latching lugs ~o enter the spout notches whereupon it drops 10¦ downwardly, and then continue the turning untll the cap becomes 11 fully latched. Frequently with such construction, the 12 attendant filling the tank belleves the cap is fully latched 13 after it moves downwardly before it is rotated to the fully 14 latched position. This results in possible l~akage of gasoline rrom the tank upon acceleration Or the automobile~
16 Conversely when a properly latched cap in unlatched~
17 it requires three motions to unlatch the same, namely, firs~
18 partlal rotation from the position at whlch the respective 19 latching lug~ engage on~ edge of the aforementionsd spout stops 20 ¦ to a position adjacent the spout notches~ next liftln~ the cap 21 I up~ardly until the latching lugs are removed through the spout 22 ¦ notches, and ~inally turning the cap to the position whereat 23 ¦ the offset retaining lugs can be removed through the notche3.
24 1 It is also possible for an attendant to accidentall~
251 latch the a~orementioned late model cap with only one latching -~
26 lug inserted through a spout notch so that the cap is not evenly 27 seated on the rlm ~or latching but is tilted. ~nis alloNs fuel 28 to escape under acceleration o~ the automobile Moreover~ late 29 model constructions have narrow spout entry notche~ throu~h 3~ - 3 -U~W orn~
;t~, HENORICSON . .

:. . : . `: . :. ~. , ~:

7~
1 wh~ch the r~talnin~ lu~ must be inserted, ~/hich renders them 2 dif~lcult to locate; and a relatively deep latching cam surface 3 (extending a substantial distance below the rim of the ~pout) is 4 provlded, which makes for a relatively expensi~/e construction.
Summary and Objects of the Inventlon 6 Summarizing the invention hereof, it embodies the feature of blocking prongs extending dow~wardly from the respecti~e latching lugs to insure proper seating of the cap g on the spout at all times, as is d-tsclosed and cla~med in appllcant's aforemention~d patent. Xn combination with such 11 prongs, a retainlng foot extends from the lower end of ea~h 12 prong. The retaining feet are arcuate, and extend circum~er-13 entially in the same dlrection about the axis o~ the spout~ ;~
14 Because they extend ~ro~ the ends of the blocking prongs, they are insertable with ths associated prongs through 16 the spout entry notches upon rotating the cap in one directlon 17 to latch the same. The arcuate or helical retainin~ ~eet ;~
form a screw threaded connec~ion with the cam su~acss of the spout. As a result, latching can be e~fected substantia1ly ~20 w~thout interruption by turning or rotating the cap in one 21 direction. It can be un2atched by ~urning the cap in an 22 opposite direction, and remo~ed by lifting ths ends of the 23 reta~ning feet through the spout notches. The retainin~ fee~
24 retain the cap loosely on the spout until the cap is manuall~
25 removed. The construction permits relatively wide notches ~-26 compared to the width of the latching lugs This enables 27 an initially loose fit of the cap on the spout, ~acllltating 28 finding the ends of the retaining feet for entry lnto the 29 notches. To ~acilitate such entry, the ends of the retaining ~w orrlcr- .
:--- ... , - ~............. . .. , .. ... . . .. ,. .. . . . . . - - - - , :. ..... - ~, , - :-- . . . - . - . :
., .

~ 1)3~
feet m~ be provid2d wlth down~ar~ly extending end proJections ~ ¦ insertable into the respectlve apout notche~ to locate the same 3 ! when the cap is placed on the spout ~or latchlnO it.
4 ¦ From the preceding it 19 seen that the ~nvention h~s

5 ¦ as its obJects, among others, the provision of economical and

6 ¦ simple means on a closure cap for an auto~obile tank filling

7 ¦ spout or the like, to insure that the cap is properly seated on

8 ¦ the spout b~ore lt is latched, ln combination w~th such means

9¦ ~ simple and economical means for retaininO the cap on the

10¦ spout while it is being unlatched while simultaneously allo~in

11 ¦ venting of gas pressure which may build up in the tank, thus

12¦ preventing the gas pressure ~rom blowing the cap away ~rom the ~3 ¦ spout as it is being unlatched. Other objects w~ll become ~.
14 ¦ apparent from the following more detailed.descriptlon and 15¦ accompanying drawings, ln whlch: :
16¦ DescriPtion of the Drawln~s .
17 ¦ Fig. 1 is an isometrlc view looking at the underside ;
¦ of the closure cap Or this invention; . :
91 Fig. 2 is an isometric view of the filling spout .~.
201 hereof illustrating its relationship to the cap of Fig. 1 be~ore .
21 ¦ they are latched; - . ..
22¦ Fig. 2A is a developed elevational v~ew illustrating a 231 filling spout with a deep cam to compare it with a shallow c~m - 24 shown ln Flgs. 2 and 4; the blocking prong and retaining ~oo~ .
-. 25 hereof being illustrated;
26 Figs. 3 through 3-D are vertlcal sections taken along 27 line 3-3 in Fig. 2 which includes an inte m ediate arcuate sect~an, .
28 illustrating the relation3hip of the sa~ety cap hereor to th 29 filling spout in various positions during the latchin~ operation;

31 in these Figs.: .
32 _ . .
: ~w Or~C!~ .
~G, II'N05?1CSON .

: , . , ~ ,. .`:`-'"','`, ' ''; ~ ' , ' " , ~ ' ' '. ' ~' : i:.. ,.i" ~

~037906 ~ig. 3 illustrates the position wherein -the retaining ;
feet are ready for positioning in -the SpOIlt notches;
Fig. 3A illustra-tes the pOSitiOIl at which a retaining foot is just ready to enter a no-tch; ;~
Fig. 3B is a position ~herein the cap has been ~ `~
partially turned after entry into the notch;
Fig. 3C illustrates a position after the cap has been -turned so that a latching lug now engages a cam surface on the spout;
Fig. 3D illustrates the fully latched position of the cap on the spout;
..: . ~.
Fig. 4 is a schematic developed view illustrating various positions of a retaining foot, b]ocking prong and latching lug with reference to the latching cam surface and entry notch during the latching operation;
Fig. 5 is a horizontal section taken in a plane indicated by line 5-5 in Fig. 3B;
Fig. 6 is a vertical, sectional elevation of an embodiment of the invention wherein the closure cap is adapted ~ -for an external bayonet type connection, portions of the view `~
being broken away to illustrate the construction more clearly;
Fig. 6A is a horizontal section taken in a plane ,~
indicated by line 6A-6A in Fig. 6, and showning the spout in elevation;
Fig. 7 is aschematic elevational view illustrating an embodiment wherein a downwardly extending end projection is provided at the end of each retaining foot insertable lnto a `~
spout notch to facilitate location of the notches; and Fig. 8 is an isometric view of the underside of a late model emission control cap, illustrating the retaining lug construction employed therein. ;

.~

~790~i Detailed Descr:iption ~ or purposes of reference in the preceding and following description, -the posi-tions of -the par-ts are referred to considering the -top o~ the spout and the cap as the uppermost part. It is to be understood, however, that -the spout and the cap may be arranged, for example, horizontally, depending on the environment wherein the spout is employed. Although particularly adapted for -the filler spout of an automobile tahk, the invention hereo~ is applicable to any o-ther filling spout ~ -for a tank wherein pressure can build up in the tank.
Referring to Figs. 1, 2, 3 through 3D, 4 and 5, a more or less conventional filling spout 2'for an automobile gasoline tank of the shallow cam type, is illustrated in association with the closure cap construction hereo~. These~parts have a bayonet type connection.
Filling spout 2 has a top comprising rim 3, and horizontal flange 4 extending inwardly and substantially even :,... .
with rim 3. Diametrically opposite entry notches 5 and 6 which provide for a bayonet connection, are formed in flange 4 which has a down turned flange 7 on each side of the spout extending ` ~;`
between entry notches 5 and 6. The under edge of one of down turned flange 7 forms a cam surface 8 which extends from an ``
edge of notch 5, slopes gradually downwardly and terminates adjacent a downwardly extending stop 9 at opposite notch 6. A
like cam surface 11 and stop 12 are formed on opposite flange 7 with cam surface 11 diametrically opposite cam surface 8, and stop 12 di~metrically opposite stop 9. The parts thus far ~;
described are conventioanlly made from stamped metal.

`:
-7- ~ `~

' ~.

~37~
The cap 13 hereof, which cooperates with -the described spout, comprises a flat -top 16 having diametrically opposite uprigh-t lugs 17 :~or grasping to turn -the cap on the spout, and a downwardly extending cylindrical flange 18 which fits over -the spout. A centering hub 19 is secured to the underside of ~ -cap top 16, and a conventional spring press sealing di~c structure 21 is fixedly secured between the cap top and centering hub 19. Centering hub 19 encloses a conventional ~ ^
.. ..
gas vapor emission control valve 21' which is preferably employed but it is not necessary for the latching features of -this invention. The parts of the cap thus far described are conventional.
As in the aforementioned patent No. 3,784,047, centering hub l9 has fixedly secured thereto a pair of diametrically opposite outwardly extending latching lugs 22 and 23 which are provided by the top ends of downwardly extending blocking prongs 22' and 23', respectively~ insertable through the notches. Although latching lugs 22 and 23 are integral with blocking prongs 22' and 23', respectively, they may be provided as separate elements in line with each other.
Extending from the lower end of the respective blocking prongs 22' and 23' and integral therewith are arcuately shaped diametrically opposite downwardly inclined or helical retaining feet 22 and 232, respectively.
These feet extend in the same circumferential direction about the axis of the cap, and are rigid with the centering hub 19 ancl the respective blocking prongs. Each forms a generally L-shaped structure with the associated blocking prongs and latching lugs; and because of their arcuate shape and downward inclination they provide a screw~,cooperable with the cam surfaces or edges 8 and 11.

:
-8- ~

~3790~
The ends of retaining feet 22 and 23a are insertable through the respective notches 5 and 6. It will be noted from Figs. 1, 2, and 3 through 3D that in la-tching the cap the ends of retaining feet 22 and 23 are inserted through the respec-tive notches 5 and 6, and turned until the upper ends of latching lugs 22' and 23' are fully inserted -through the respective notches 5 and 6. Upon continued turning of the cap, the latching lugs ride over cam surfaces 8 and 11 whereupon the cap - `
becomes fully latched when the latching lugs and associated blocking prongs engage against the respective stops 9 and 12; ~ -tight latching and sealing of the cap being malntained by the ~ ;
spring pressed sealing disc structure 21. ~ ~
Figs. 3 through 3D illustrate various positions as ~ `
the cap is turned or rotated clockwise to latch the same; in this connection the L-shaped structures are in the same relation-ship as in Figs. 1 and 2. Fig. 4 schema-tically depicts development of the L-shaped structure 23, 23' and 23 insertable -~
through notch 6 in the spout from adjacent which the end of -sloping cam surface 11 e~tends. The left-hand portion of Fig. 4 ~ ~;

shows the position just after retaining foot 23 has entered notch 6, while the phantom lines indicate further positions after the cap has been rotated clockwise.
It will be noted that cam surface 11 has a slight i~
gradual slope from edge 6' of entry notch 6. This facilitates insertion of the retaining foot and rotation of the L-shaped structure. When the cap is turned, latchgng lug surface 23 rides against cam surface 11, being pressed against it by the -spring pressed sealing disc structure 21 as it engages the rim of the spout. When latching lug 23 and associated blocking :, _g_ ,i : ~

~03790~ ~:
prong 23' engage against s-top 12, the cap becomes tightly latched ~ ~
by the spring pressure exerted by spring pressed sealing , struc-ture 21. The opposite L-shaped structure 22, 22' and 22 is simultaneously inser-ted -through notch 5 (Fig. 1), and latches in the same manner.
As in the aforementioned application, blocking prongs 22' and 23' insure that the cap becomes evenly seated - -on the spout rim 3 before it can be rotated for latching the same, to thus prevent latching with only one lug. Unlatching is effected by rotating the cap in a counterclockwise direction until the ends of the retaining feet are removed through the respective entry notches 5 and 6. ~ -During such unlatching, it will be noted that ~ ;
retaining feet 22 and 23 are underneath latchi;ng surfaces 8 and 11, respectively, as the cap is be~ng unlatched; and during this period pressure built up in the tank is vented through entry notches 5 and 6, and between the flange 18 and the outside surface of spout 2. However, such pressure cannot blow the cap away from the spout because the retaining feet can engage such surfaces until the gas has been completely vented. Thus possible injury to the person unscrewing the cap is precluded.
Each of the latching lugs and associated blocking prongs and retaining feet are of a width substantially less than the width of each of spout notches 5 or 6 as can be seen best from Fig. 5. Thus an initial loose fit is provided which facilitates locating the notches and entrance of the ends of the retaining feet into the notches.

:, . : . . . ~ - - - .: , . . - , 1~379~)6 An important feature to facilitate latching and unlatching of the cap is the shallow latching cam employed herein. Referring to Fig. 4, it will be noted -that latching surface 11 leads directly from the edge 6' of notch 6, and -the latching surface slopes gradually from such edge, being located a relatively short distance from the top o~ the spout. Fig. 2A
. . .
illustrates a deep cam construction wherein latching surface ll extends from an edge 6 of flange 7 a substantial distance.
Consequently, it blocks smooth entrance of retaining foot 23 underneath cam surface 11 . The shallow cam not only has the advantage described but it is also easier to manufacture, and consequently reduces cost compared to a deep cam.
The precise depth of the cam surface below the rim of the spout is not particularly critical, nor is the degree o~ slope of the cam surface critical. All that is desirable is ~or the slope to be gradual, and ~or the end of the cam ~;~
surface to lead gradually from the entry notch as shown in Fig. 4 to allow retaining foot 23 to slide into position easily. A suitable cam slope is between about 4 to 6.
Fig. 8 depicts a present popular type of late model closure cap for a deep cam on the spout. Diametrically opposite latching lugs 31 are offset or staggered relative to opposite retaining lugs 32 which are provided on downwardly extending brackets 33 also located diametrically opposi-te each other. In this construction, two distinct turning operations are required -~
to latch the cap, after retaining lugs 32 have been inserted through the spout notches, namely, an initial turning until -latchlng lugs 31 are opposite the notches in the spout whereupon the cap drops down vertically, and a final turning to latch the same by the latching lugs riding over the cams.

~.037gO6 An inexperienced a-ttendant, aE`ter inser-ting the retaining lugs through the notches ancl making the first turning of the cap, might not realize that the second turning operation -~
is still required, and, therefore not perform the f`inal turning ;~
to latch ~nd seal the cap. Coosequent;ly, under acceleration of the vehicle gasoline can escape from the spout which is not ~ . .
uncommon. This is precluded by the present construction because latching is accomplished essentially by one continuous sweep or turning of the cap to the fully latched and sealed ;~
position. Latching can be effected with a rotation of the cap of about 150 compared to about 250 with late model caps. ;;
Referring particularly to Fig. 7, each end of a retaining foot, for example retaining foot 22a with reference to Fig. 1, may be provided with a downwardly extending end projection 22 insertable into a notch 5 to facilitate location of the respective notches when the cap is placed on the spout for latching it. This feature is not necessary but may be employed if so desired.
In the embodiment of the invention illustrated, which , is for a conventional gasoline tank filler spout for an automobile, the spout is about 2 1/4 inches outside diameter with horizontal flange about 1/4 of an inch wide, the depth of cam flanges 7 at the highest point being about 3/16 of an inch, notches 5 and 6 about 5/8 of an inch wide, blocklng prongs 22' and 23' each about 3/16 of an inch wide, and about 5/8 inch long, and stops 9 and 12 each of about 5/8 of an inch wide and 3/8 of an inch long. For the described size, the arcuate length of each retaining foot is about 7/8 of an inch and its angle of inclination about 5 . The above dimensions are not ','' ~37~6 `:
particularly critical bu-t are merely given by way of example, as it is to be unders-tood -that the length o~ -the blockir-g ~
prongs and retaining feet, and the an~sle of the re-taining feet ~ ;
may vary depending upon the size of the spout and the particular dimensions of the cap. As previously indicated, each of the L-shaped structures is a rigid continuous structure rigid with centering hub 19. It may be formed as a stamping integral with the hub or as a separate rigid structure welded to the metal hub.
The previously described embodiment of the invention is an internal bayonet connection which is common for closure ,.
caps on automobile gasoline tanks; and the latching and L-shaped structure is on the exterior face of centering hub l9 for entry ;
through internal bayonet notches in the spout. However, as disclosed in the aforementioned application, the principle of the invention is also applicable to an external bayonet -~

connection, which is illustrated in Figs. 6 and 6A wherein, ~ -' for example, a radiator filling spout 36 is shown. -Opposite exterior entry notches 37 are provided in horizontal exterior flange 38 of the spout from which extends a downwardly extending flange 39. The under surface 41 of flange 39 provides the camming surfaces. L-shaped structures 42 having the described retaining fee-t 43 with locater extensions 44 at their ends, are rigid with the interior face of centering hub. 45. They are insertable through notches 37 and the upper ends 44 serve as latching lugs to engage against cam surfaces 41 ;
when the cap is fully positioned on -the spout and rotated in a clockwise direction.

-13-.,. - - . . . ~ , , , , ,:

Claims

HE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A safety closure cap for connection with a filler spout of an automobile tank or the like comprising a top, said spout having an open filling end surrounded by a rim, a spring pressed sealing disc structure secured to the underside of the top to seal against said rim, the spout having adjacent said rim opposite cam surfaces which are separated by opposite entry notches, opposite latching lugs on the cap secured to a downwardly extending cylindrical centering hub secured to the underside of the cap top and being insertable through the notches, turning of the cap in one direction latching the cap against said rim of the spout by the lugs riding over the cam surfaces, blocking prongs secured to said centering hub and extending downwardly from and in alinement with the respective latching lugs to insure proper seating of the cap on the spout, and an arcuately shaped slightly downwardly inclinded retaining foot extending circumferentially about the axis of said hub from the lower end of each prong and having its lower end spaced from the prong and forming a generally L-shaped rigid structure with said blocking prong, such feet extending in the same circumferential direction about said hub to form a screw and being insertable with the associated prongs through the entry notches upon turning of the cap in said one direction to latch the same; and upon turning of the cap in an opposite direction to unlatch the same, said feet being engageable with said cam surfaces upon axial displacement of the cap to retain the cap loosely on the spout until said lower ends of the feet are removed manually through the entry notches to thus allow venting of gas pressure which may have built up in the tank and thus prevent the gas pressure from blowing the cap away from the spout as it is being unlatched.

2. A safety closure cap for connection with a filler spout of an automobile tank or the like wherein said spout has an open filling end surrounded by a rim, and opposite cam surfaces adjacent said rim separated by opposite entry notches, each cam surface having a slight gradual downward slope from an edge of the associated entry notch, said cap comprising a circular top, a downwardly extending centering hub fixedly secured to the underside of said top and insertable into the open end of said spout, a spring pressed sealing disc structure about said centering hub secured to the underside of said cap top for sealing against said spout rim; and rigid generally L-shaped structures secured to said hub at opposite sides thereof, each structure comprising an upright blocking prong insertable through an entrance notch to insure proper seating of the cap on the spout, each prong terminating adjacent the spout top in a latching lug engageable with a cam surface, and an arcuately shaped slightly downwardly inclined retaining foot extending circumferentially about the axis of said hub from the lower end of each prong and having its lower end spaced from the prong, said feet extending in the same circumferential direction about said hub to form a screw and being insertable with the associated prongs through the entry notches upon turning of the cap in one direction to effect latching of said latching lugs against said cam surfaces; the retaining feet upon turning the cap in an opposite direction to unlatch the same being engageable with said cam surfaces upon axial displacement of the cap to retain the cap loosely on the spout until said blocking prongs and ends of the retaining feet are removed manually through such said entry notches.

3. A safety closure cap for connection with a filler spout of an automobile tank or the like comprising a top, said spout having an open filling end surrounded by a rim, a spring pressed sealing disc structure secured to the underside of the top to seal against said rim, the spout having adjacent said rim opposite cam surfaces which are separated by opposite entry notches, opposite latching lugs on the cap insertable through the notches which upon turning the cap in one direction latch the cap against said rim of the spout by the lugs riding over the cam surfaces, prongs extending downwardly from the respective latching lugs to insure proper seating of the cap on said rim of the spout, and an arcuate downwardly inclined retaining foot extending circumferentially about the axis of the cap from the lower end of each prong and having its lower end spaced from the prong, said retaining feet extending in the same circumferential direction to form a screw and being insertable with the associated prongs through the entry notches upon turning of the cap in said one direction to latch the same; and turning of the cap in an opposite direction to unlatch the same, said feet being engageable with said cam surfaces upon axial displacement of the cap to retain the cap loosely on the spout until said lower ends of the feet are removed manually through the entry notches to thus allow venting of gas pressure which may have built up in the tank and thus prevent such gas pressure from blowing the cap away from the spout as it is being unlatched.

4. The safety closure cap of claim 3 wherein said end of each retaining foot has a downwardly extending end projection insertable into the respective notches to locate the same when the cap is placed on the spout for latching it.

5. The safety closure cap of claim 3 wherein each prong is rigid and in alinement with the associated latching lug and is substantially perpendicular to the top of the cap.

6. The safety closure cap of claim 4 wherein each locating projection is rigid with the associated retaining ?oot and is integral therewith.

7. The safety closure cap of claim 3 wherein the width of each latching lug is substantially less than the width of each of said spout notches to form initially a loose fit of the cap on the spout.

8. The safety closure of claim 3 wherein said cap has a downwardly extending cylindrical flange for sur-rounding the spout.

9. The safety closure of claim 3 wherein each prong and its associated retaining foot is a continuous rigid structure.

10. The safety closure of claim 9 wherein the end of each cam surface of the spout adjacent an edge of an associated entry notch has a gradual slope from said edge to facilitate guiding of a cap retaining foot onto the cam surface.

11. The safety closure cap of claim 3 wherein the prongs and retaining feet on the cap are arranged to co-operate with external notches on the spout.