Dispenser for pasty compositions

Dispensers for pasty compositions having a housing (1) with a piston (2) which is displaceable only in the emptying direction and an actuating handle (H) which is developed on a head piece (5) which can be pressed bellows-like in the direction towards the piston (2) and has a dispenser outlet opening (O) from which there extends, directed inwards, a tube (7) whose inner mouth-end (7") dips freely into the pasty composition in every position of the bellows (B). A structural shape which is simple to manufacture and nevertheless dependable in operation, comprises a flap valve (9) with passage opening lying in the direction of the tube (7) (arrow z), below the inner mouth-end (7") of the tube (7), in the cover (8) of the housing (1) from which a mounting collar (6) for the bellows (B) extends.

FIELD AND BACKGROUND OF THE INVENTION 
The present invention refers to a dispenser for pasty compositions, having 
a housing containing a piston which is displaceable only in the emptying 
direction and an actuating handle on the outside which is developed on a 
head piece which can be compressed bellows-like in the direction towards 
the piston, said head piece having a dispenser outlet opening from which 
there extends, directed inwards, a small tube, the inner mouth-end of 
which extends freely into the pasty composition in every position of the 
bellows. 
A dispenser of this kind is known from Federal Republic of Germany OS 30 42 
285. The pasty composition present in the small tube exerts a valve 
function. The pulling of the piston over the column of filling material is 
effected by way of priority, i.e. before the residual amount in the small 
tube which acts in blocking fashion and in plug-like manner could 
compensate for the existing vacuum by air. The blocking of the piston in 
the other direction is effected by use of a so-called clamping module. The 
latter is placed on the wide surface of the piston facing the stand-side 
end of the housing; it is a multi-pointed star-shaped structural part of 
spring steel. The diameter circumscribing the ends of the points is 
greater than the inside diameter of the housing so that the ends of the 
points hook themselves as oblique supporting feet on the inner wall of the 
housing. Such a structural part is relatively expensive for a throw-away 
mass-produced article. Also an additional mounting step results. In 
addition to this, relatively high frictional forces must be overcome, as a 
result of which certain limits are established with respect to the 
viscosity. 
The object of the present invention is so to develop a dispenser of this 
type in a form which is simple to manufacture and stable in use that the 
one-sided displacement of the piston is effected without structural parts 
on the piston. 
SUMMARY OF THE INVENTION 
According to the invention below the inner mouth-end (7") of the tube (7) 
there is present in the cover (8) of the housing (1) from which a mounting 
collar (6) for the bellows (B) extends, a flap valve (9) with passage 
opening (10) lying in the direction of the tube (arrow z). 
As a result of this development the relatively expensive clamping module 
can be dispensed with. Nevertheless, the customary reliability in use is 
retained. The structural means are simple since a flap valve with passage 
opening lying in the direction of the small tube is located below the 
inner mouth-end of the small tube within the cover of the housing from 
which cover an attachment collar for the bellows extends. Such a flap 
valve can be formed directly on the functional part in simple manner. A 
high degree of economy is present. Furthermore, considerably less 
frictional forces occur on the piston, which further adds to the 
reliability of operation and, in addition, permits the use of a wide range 
of viscosities for the filling material. Pressure is produced only on the 
valve flap and no longer on the piston. It is furthermore advantageous, in 
accordance with the invention, that the section of the inner mouth-end of 
the small tube overlaps the attachment collar. On the one hand, the 
maximum length of the inside of the bellows is utilized for the tube 
while, on the other hand, a certain actuating end-stop for the bellows 
results from this arrangement via the tube. Substantially loss-free 
dispensing can be obtained by simple means in the manner that on its upper 
side the piston forms a flat wall extending parallel to the housing cover 
which centrally bears the valve flap. In this connection, the top 
advisedly terminates with one of the customary edge lips of the piston. 
With regard to the development of the flap valve preferably the valve flap 
is formed on the housing cover, peripherally and of the same material, 
over a thinned cross section which has an initial tension inherent in it 
as a result of the injection moulding of the valve flap in housing 
inwardly-directed, perpendicular position and by threading through the 
passage opening. Thus, the valve flap is always reliably urged into 
closing position solely by the restoring force which is inherent in the 
material. In addition, there is also the weight itself, even though 
slight, of the valve flap, namely with due consideration of the position 
of use which customarily occurs. With respect to long-time storage of the 
dispenser, it is also beneficial that a closure stopper of the dispenser 
outlet opening is acted on by a part of an annular rib on the cover inner 
surface of a cup-shaped covering cap of round cross section. Upon placing 
the dispenser in use it is no longer necessary constantly to coordinate 
the closure stopper again with the tube since the contents of the tube 
cannot dry out, due to the permanent moisture connection to the remaining 
supply which is close to delivery, within the period of consumption which 
is customarily taken as a basis, particularly as the cover cap can always 
be coordinated again.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The housing 1, which is developed as a long cylinder, contains a piston 2. 
The edge lips 2' of said piston are guided on the inner wall 1' of the 
cylindrical housing. The housing 1 itself is open but can be closed by 
means of a bottom plate 3 which can be snapped into position. 
The delivery-side closure of the housing 1 is formed by an actuating handle 
H which is arranged opposite the widened standing base 4 of the housing. 
The actuating handle is a head piece 5 which can be compressed in 
bellows-like manner in the direction towards the piston 2 and always comes 
back up again by itself into its basic position. The head piece is placed 
on a mounting collar 6 which is narrower than the housing 1. By means of a 
thread or ring and groove engagement in cooperation with the restoring 
force of the flexible material which forms the head piece 5 there is a 
connection between the two parts which is stable in use. 
The head piece 5 forms a dispenser outlet opening O which is reduced in 
cross section. From said opening there extends a tube 7 which extends into 
the inside R 1 of the dome-shaped head piece 5. The outlet-opening end of 
the tube commences near the edge both in the cover 5' of the head piece 5 
and also in part in the wall 5" of the head piece. This wall 5" is 
slightly wasp-shaped. The tube passes into a protuberance 7'" formed by 
the head piece 5 and extending somewhat beyond the cover 5. In addition to 
the direct development of the tube thereon by injection molding there is, 
of course, also the possibility of producing it as a separate structural 
part and holding it on the head piece 5 by welding or by gluing. As can be 
noted from FIG. 2, the tube 7 extends inclined at an acute angle to the 
longitudinal central axis y--y of the tubular or cylindrical housing 1. 
The angle designated alpha is about 25.degree. . The tube can also extend 
parallel to the axis y--y, which would be more favorable for injection 
molding. 
The outer mouth-end 7' of the tube which forms the outlet opening O extends 
almost up into the region of the extended cylindrical plane of the housing 
1. The inner mouth-end 7", on the other hand, points substantially into 
the center of a cover 8 which divides the inner space R 1 of the head 
piece 5 from the storage space R 2 of the housing 1. The cover extends 
parallel to the standing surface St and is developed on the housing 1. The 
distance between the inner mouth-end 7" and the top of the cover 8 
corresponds approximately to the inside diameter of the tube 7. As a 
result of the aforementioned inclination of the tube there is also 
obtained a free spacing from the inside of the mounting collar 6. The 
mounting collar extends from the cover 8. 
The inner mouth-end section of the tube 7 overlaps the mounting collar 6. 
Extending into a pot-like chamber formed by the collar 6 on the cover 8. 
In the central region of the cover 8 there is a flap valve 9. The latter 
extends over the edge of its passage opening 10 in the cover 8. The 
contour of the flap valve 9 can be noted from FIG. 4. The contour of the 
passage opening is shaped accordingly. In order to keep the expense for 
parts low, the valve flap 9' is formed on the cover side. The hinge point 
is formed by a thin cross section, namely a so-called film hinge. The 
latter bears the reference number 11. The film hinge 11 extends over the 
entire width of the valve flap 9', all of the edges of which are beveled. 
In this way there is a thin-lipped edge which rests on the also 
thinned-wall edge 10' of the passage opening 10. In addition to a resting 
which is dependent on gravity there is also obtained a resting under 
spring force due to the fact that during the injection molding the valve 
flap 9' of the housing cover 8 is formed in a housing-inwardly-directed, 
perpendicular position to the standing surface St (see FIG. 4, alignment 
in solid lines) whereupon then, after hardening, the flexible valve flap 
9' is threaded through the valve hole 10. For the formation of the initial 
tension 90.degree. are used. This alignment is also favorable for the 
injection molding. No transverse slide need be used. 
In order to increase the internal stability of the valve flap 9' a slightly 
ridge-shaped profile is selected, as can be noted from the sectional 
showing in FIG. 2. The ridge line 12 extends parallel to the direction of 
extension of the film hinge 11. The ridge line intersects the longitudinal 
center line y--y. 
In order to obtain a dispensing which is as free of loss as possible with 
respect to the storage space R 2 of the container, the piston 2 forms, on 
its top, a flat wall 13 which extends parallel to the housing cover 8 
which centrally bears the valve flap 9'. Said wall is part of a cover-side 
protrusion of a piston middle wall 14 which commences in the cylindrical 
section of the piston midway between the ring-shaped planes of the edge 
lips 2', 2". 
By elimination of the clamping module of the prior art, it is possible, in 
case of a corresponding pulling device on the piston 2, for this dispenser 
to be reused, i.e. to be refilled from a larger storage container. For 
this purpose the bottom plate 3 must first of all be removed. By 
corresponding beveling of the region of the housing inner wall 1' close to 
the bottom, the reintroduction of the piston 2 can be easily effected. 
For the equalizing of air the bottom plate 3 is provided with a hole which 
at the same time can be used to help in removal. 
The zone forming the bellows B of the head piece 5 is obtained by a 
horizontal constriction E of flat V shape. This constriction extends over 
half the cross-sectional width of the head piece 5 on the side facing away 
from the opening O. The ferrule of the bellows is designated 15 (FIG. 2). 
The acute-angle coordination of the tube 7 in the part of the head piece 
opposite the constriction E is such that upon actuation of the bellows the 
tube is swung out peripherally from the region of the upward-swinging 
valve flap 9, which is spaced in front thereof, and tips practically into 
a position parallel in space to the longitudinal center axis y--y. The 
section of the mounting collar 6 present there can serve as stop. The film 
hinge is arranged at a distance corresponding to the diameter of the tube 
from that section of the mounting collar 6. 
The head piece 5 is gripped over by a cover cap 16. The latter has an 
outside diameter which corresponds to that of the housing 1. In this way 
there is obtained a smooth continuation of the cylindrical shape up into 
the cap region. The cover cap 16 can be snapped on. The corresponding 
means are developed on its edge and cooperate with corresponding means on 
the edge of the head piece. 
The cover cap has a further development to the effect that it cooperates in 
the securing of a closure stopper 17 which is inserted into the dispenser 
outlet opening O in the manner that a partial section 18' of an annular 
rib 18 developed on the cover inner surface of the cup-shaped cover cap 
acts on the back of the plug. This back is arranged obliquely and the end 
surface of the annular rib 18 is beveled accordingly. 
The back of the stopper continues into an edge which, extending beyond the 
edge of the tube, passes into an inwardly-directed pull tab 19. The latter 
is bent at an angle and extends essentially parallel to the slightly 
curved cover of the cover cap which terminates in the edge regions in a 
stronger transverse curvature which adjoins the cylindrical outer wall of 
the cover cap. 
The dispenser described operates in the following manner: After removal of 
the cover cap 16, the head piece 5 is pressed, in the region forming the 
bellows B which is transversely grooved or otherwise roughened on top, 
downwardly in the direction towards the piston 2. Pressure is produced 
merely on the flap valve 9. The pasty composition (not shown) present in 
the inner space R 1 forces its way, passing through the tube 7, as a 
result of the reduction of the volume within the head piece, in the 
direction towards the outlet opening O and finally emerging from the outer 
mouth-end 7'. If the head piece 5 is now relieved of load, a vacuum is 
produced in the inner space R 1. The flexible head piece 5, returning into 
its basic position, now pulls the piston 2 in the direction indicated by 
the arrow X over the column of filling material. The backward movement is 
at an end before the composition still remaining in the tube as a "plug" 
can reach or depart from the inner mouth-end 7". The vacuum effects the 
swinging up of the valve flap 9' in delivery direction (arrow z) so that 
the flap valve 9 abuts against the inner mouth-end 7" of said tube; the 
head piece 5 fills up via the passage opening 10. The spring biased valve 
flap 9' thereafter by its biasing moves back into its closed position. The 
decisive factor in all of this is that the tube 7 forms a corresponding 
resistance in cross section and length with adaptation to the viscosity of 
the pasty composition and the speed of flow which has occurred, this 
resistance bridging over the resultant vacuum. 
The inner mouth-end 7" of the tube 7 is spaced above said flap valve 9 by a 
distance substantially equal to an inner diameter of the tube (FIG. 2), 
the flap valve 9 having a length from the hinge 11 to its right-hand end 
in the drawings substantially greater than said distance. When pressing 
down on the bellows B as shown in FIG. 5 the flap valve 9 is further 
pressed down securely closing the passage opening 10 and the tube 7 swings 
away from the flap valve 9 (namely, the inner mouth-end 7" of the tube 7 
swinging away from the flap valve 9) and the pasty composition exits from 
the outer mouth-end 7' of the tube 7. When the bellows B is released of 
pressing by the operator's thumb being removed, the tube 7 swings back as 
shown in FIG. 6 and the flap valve 9 swings up due to the vacuum created 
in the space R 1 in the bellows and the flap valve 9 abuts against the 
inner mouth-end 7" of said tube by the flap valve 9 swinging up opening 
the passage opening 10. 
The abutment (FIG. 6) of the flap valve 9 against the tube 7 orients the 
flap valve 9 so it forms an acute angle with the plane of the opening 10 
so that the flap valve 9 is oriented for subsequent closure of the passage 
opening 10 by its own spring-biasing as well as by pressing of the bellows 
B, said abutment also orienting the flap valve 9 for impeding a back flow 
of pasty composition in the tube 7 (providing a dam zone or pressure 
build-up zone) upon the release of pressing on the bellows B.