U.S. patent application number 13/754391 was filed with the patent office on 2013-08-01 for dispenser.
This patent application is currently assigned to Hilti Aktiengesellschaft. The applicant listed for this patent is Hilti Aktiengesellschaft. Invention is credited to Herbert Ginter.
Application Number | 20130193168 13/754391 |
Document ID | / |
Family ID | 47561466 |
Filed Date | 2013-08-01 |
United States Patent
Application |
20130193168 |
Kind Code |
A1 |
Ginter; Herbert |
August 1, 2013 |
DISPENSER
Abstract
In the case of a dispenser for packs containing single-component
or multi-component compounds, having a receptacle for the pack,
having at least one piston rod and having an advancing mechanism
for moving the at least one piston rod in the direction of the
receptacle, whereby the advancing mechanism has at least one
clamping element that can engage with the piston rod and that can
be detachably clamped to the at least one piston rod in order to
move it, it is provided that the advancing mechanism is movably
joined to the receptacle for the pack in such a way that the
advancing mechanism with the piston rod can be moved along the
advancing axis out of a first position into a second position. This
can prevent or minimize afterflow of the compounds.
Inventors: |
Ginter; Herbert;
(Germaringen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hilti Aktiengesellschaft; |
Schaan |
|
LI |
|
|
Assignee: |
Hilti Aktiengesellschaft
Schaan
LI
|
Family ID: |
47561466 |
Appl. No.: |
13/754391 |
Filed: |
January 30, 2013 |
Current U.S.
Class: |
222/391 ;
222/137 |
Current CPC
Class: |
B65D 83/0022 20130101;
B05C 17/0123 20130101; B05C 17/00553 20130101; B05C 17/00583
20130101 |
Class at
Publication: |
222/391 ;
222/137 |
International
Class: |
B67D 7/60 20100101
B67D007/60; B67D 7/70 20100101 B67D007/70 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2012 |
DE |
102012201295.8 |
Claims
1. A dispenser for at least one pack containing a single-component
or multi-component compound, the dispenser comprising: a receptacle
for the pack; at least one piston rod; and an advancing mechanism
for moving the at least one piston rod in a direction of the
receptacle so as to define an advancing direction, the advancing
mechanism having at least one clamping element engageable with the
piston rod and detachably clampable to the at least one piston rod
in order to move the at least one pison rod, the advancing
mechanism with the piston rod being movably joined to the
receptacle for the pack in such a way that the advancing mechanism
with the piston rod can be moved along an advancing axis out of a
first position into a second position relative to the
receptacle.
2. The dispenser as recited in claim 1 wherein the advancing
mechanism is joined to the receptacle for the pack in such a way
that the advancing mechanism, together with the at least one piston
rod, is movable opposite to the advancing direction.
3. The dispenser as recited in claim 2 wherein the advancing
mechanism is movable at least one of actively and passively.
4. The dispenser as recited in claim 1 wherein the advancing
mechanism and the receptacle for the pack are joined together by at
least one decoupling element.
5. The dispenser as recited in claim 4 wherein the at least one
decoupling element allows a path-controlled and force-controlled
return stroke of the piston rod opposite to the advancing
direction.
6. The dispenser as recited in claim 5 wherein the at least one
decoupling element is a carriage system, a disc spring or a plastic
damper.
7. The dispenser as recited in claim 4 wherein the at least one
decoupling element is a carriage system, a disc spring or a plastic
damper.
Description
[0001] This claims the benefit of German Patent Application DE 10
2012 201 295.8, filed Jan. 31, 2012 and hereby incorporated by
reference herein.
[0002] The present invention relates to a dispenser for packs
containing single-component or multi-component compounds, having a
receptacle for the pack, having at least one piston rod and having
an advancing mechanism for moving the at least one piston rod in
the direction of the receptacle, whereby the advancing mechanism
has at least one clamping element that can engage with the piston
rod and that can be detachably clamped to the at least one piston
rod in order to move it.
BACKGROUND
[0003] Such a dispenser serves to expel dispensable or pasty
compounds that are contained in packs, such as mortar or sealing
compounds, at an application site. The dispenser allows an exact
metering as well as a precise application of the compound in
question. Normally, the dispenser has a piston arranged on a piston
rod, whereby said piston can act on the pack and force the pasty
compound contained in the pack against an outlet opening. The
piston rod is driven by an advancing mechanism that can be
detachably clamped onto this piston rod. For this purpose, the
advancing mechanism has a clamping element that can clamp onto the
piston rod. At the end of a dispensing stroke, at least one
additional clamping element blocks the at least one push rod and
holds it in the end position of the last stroke. As a result, the
advancing mechanism, together with the piston rod, forms a unit. In
order to retract the piston rod, for instance, when the pack is
replaced, a clamping element that is engaged with the piston rod is
uncoupled by means of an unlocking mechanism, and the piston rod is
manually retracted.
[0004] Dispensers of the generic type are described in German
patent application DE 42 31 419 A1, in German utility model DE 20
2004 018 368 U1 as well as in the German translation of European
patent DE 699 06 694 T2, related to U.S. Pat. No. 6,286,718, all of
which are hereby incorporated by reference herein.
[0005] Packs with several chambers which contain the components of
a multi-component, flowable, pasty compound, such as mortar and
sealing compounds, and in which the chambers consist essentially of
cartridges or film tubes, are already known. The term "packs"
encompasses, for instance, cartridges having one or more
compartments for one or more components of the single-component or
multi-component compound that is to be applied and that is either
contained directly in the compartments of the cartridge or else
that is packaged, for example, in film pouches. The term "packs"
also encompasses film pouches that are filled with one or more
components of the single-component or multi-component compound to
be applied and that are inserted into a receptacle that is separate
or that is arranged on the dispenser such as a cartridge holder
(also called a cassette). In the case of multi-component compounds,
the cartridge holder has separate chambers, corresponding to the
number of components and thus to the number of film pouches or
cartridges. The most common application is the "side-by-side"
application, in which the components of the multi-component
compound are packaged in packs that comprise film pouches or
cartridges arranged next to each other, whereby, for instance, in
the case of two-component compounds, two film pouches or cartridges
are provided.
[0006] For manufacturing-related reasons, especially pasty
compounds contain a certain gas fraction that render the compounds
compressible. This compressibility as well as the
compressibility/elasticity of the entire system consisting of the
compounds, the pack and the dispenser account for a dynamic
behavior on the part of the entire system.
[0007] When it comes to dispensers of the generic type, the
dispensing procedure is carried out intermittently, that is to say,
one stroke at a time. At the beginning of the dispensing procedure,
in other words, at the beginning of the dispensing stroke, since
the compounds in the cartridge chambers or the film pouch are
compressible, they are first compressed until the pressure in the
cartridge chambers or in the film pouches is so high that the
compounds start to flow out. Once this point has been reached and
if the dispensing movement continues, the compounds flow out of the
cartridge chambers or out of the film pouches at the envisaged
mixing ratio and are then fed to a mixing element such as a static
mixer. At the end of the dispensing stroke, the system is relieved
until the pressure in the cartridge chambers or in the film pouches
has dropped to such an extent that the compounds no longer flow out
(hereinafter referred to as the relaxation phase). During this
relaxation phase, it can be observed that the compounds continue to
flow, even though no more stroke movement occurs; this is called
"afterflow".
[0008] Particularly in the case of injection mortars,
multi-component systems such as, for instance, two-component mortar
compounds that have to be mixed at a specific mixing ratio in order
to cure properly, have become well-established. Since the two
components of a two-component system usually exhibit different
compressibility/elasticity behavior, during the afterflow, mortar
enters the inlet of the static mixer at a mixing ratio that
sometimes diverges markedly from the envisaged ratio. This mixing
ratio, which results automatically during the afterflow phase,
depends on the compressibility/elasticity characteristics of the
two mortar components in the system, whereby the compressibility of
the compounds, the elasticity of the cartridge or pack parts, the
volume of the mortar compound and the like all play a role. Under
unfavorable conditions, the detrimental effect of afterflow can be
so pronounced that the mortar coming out of the mixer no longer
displays a mixing ratio that is acceptable for the system, as a
result of which the mortar compound cannot cure properly.
SUMMARY OF THE INVENTION
[0009] A drawback of the prior-art dispensers having a
clamping-element drive is that, at the end of a dispensing stroke
and thus at the end of the dispensing procedure, the piston rod is
secured in the final position of the last stroke. As a result, the
relief of force or pressure in the entire system can only take
place in one direction, namely, through afterflow of the mortar
components into the mixing element.
[0010] Mechanical dispensers with a clamping-element drive have a
manual force relief mechanism for when the pack needs to be
replaced. However, if such a relief mechanism is activated
immediately after the last dispensing stroke, this causes an
uncontrolled, usually large movement of the piston rod, which gives
rise to unwanted handling problems with the dispenser. Depending on
the actual dispensing forces, the manual force relief causes the
piston rod to travel sometimes large, uncontrolled relief paths.
These relief paths have to first be compensated for during the next
dispensing procedures by executing several strokes on the
dispenser, translating into additional work and time expenditure
for the user. Moreover, this process is markedly disrupted in
applications for which a specific number of strokes or specified
piston rod movements are prescribed in order to expel the requisite
mortar quantity, as is the case for applications in hollow
substrates.
[0011] A targeted force relief or path relief for the piston rod
and thus for the entire system after a dispensing procedure or
after a stroke is difficult to implement in the mechanical
dispensers that have a clamping-element drive and that are
available on the market nowadays. Consequently, targeted force
relief or path relief has not been implemented up until now.
[0012] It is an object of the present invention is to provide a
dispenser that avoids the above-mentioned disadvantages by means of
a controlled return stroke of the piston rod at the end of the
stroke, thus ensuring a targeted path relief or pressure relief of
packs containing pasty compounds.
[0013] The invention provides the idea of minimizing or even
entirely preventing afterflow of mortar by means of a targeted
force relief of the at least one piston rod after the dispensing
procedure or after a stroke. In this manner, on the one hand,
undesired contamination of the dispensers and of the work
environment can be avoided and, on the other hand, disruption of
the mixing or curing due to different levels of afterflow of the
component compounds in multi-component systems can be
prevented.
[0014] The present invention implements an at least partial
pressure relief or force relief of all of the components in the
single-component or multi-component packs and dispensers by means
of a controlled return stroke of the piston rod after each
dispensing stroke, which is made possible by a flexible
force-controlled and/or path-controlled connection between the
receptacle for the pack and the advancing mechanism with the piston
rod. When it comes to a dispenser for a pack containing
single-component or multi-component compounds having a receptacle
for the pack, having at least one piston rod, and having an
advancing mechanism for pushing the at least one piston rod in the
direction of the receptacle, whereby the advancing mechanism has at
least one clamping element that can engage with the piston rod and
that can detachably clamp onto it in order to push the at least one
piston rod, it is provided according to the invention that the
advancing mechanism is movably joined to the receptacle for the
pack in such a way that the advancing mechanism can be moved by
means of the piston rod along the advancing axis out of a first
position into a second position.
[0015] The advancing mechanism with the piston rod of the
dispensers used up until now is firmly joined to the receptacle for
the pack, so that after each dispensing stroke, the at least one
clamping element is always returned to a defined initial position,
for instance, by means of a spring or another mechanism, and the at
least one piston rod is held by at least one additional clamping
element in the position that is reached after the dispensing
stroke. This prevents a return stroke of the piston rod opposite to
the direction in which the pressure is exerted. In this manner,
after each dispensing stroke, the at least one piston rod has a
defined, fixed position in the pack used for the dispensing
procedure. Consequently, after each dispensing procedure, the force
or pressure in the system can only be relieved in the dispensing
direction. This causes afterflow of the compound, which, in the
case of multi-component compounds, can vary for each individual
compound, depending on its specific compressibility/elasticity.
[0016] The advancing mechanism according to the invention, which
comprises the at least one clamping element that serves to advance
the at least one piston rod, is arranged in such a way that it is
not rigidly joined to the receptacle, but rather so as to allow a
movement relative to each other along the advancing axis, that is
to say, between the receptacle for the pack and the advancing
mechanism. Owing to the movement of the advancing mechanism, after
a dispensing stroke, the at least one piston rod is no longer held
in a fixed position with respect to the receptacle and thus with
respect to the pack. This allows the advancing mechanism to be
moved, and thus also the at least one piston rod, opposite to the
direction of the stroke movement (return stroke), as a result of
which the system can relax in the direction of the advancing
mechanism. At the time of the next dispensing stroke, the return
stroke then has to be compensated for by a longer path on the
dispensing lever.
[0017] Advantageously, the advancing mechanism with the piston rod
is movably joined to the receptacle for the pack in such a way that
the advancing mechanism with the piston rod can be moved along the
advancing axis out of a first position into a second position. This
allows the advancing mechanism to be moved together with the at
least one piston rod opposite to the direction in which pressure is
exerted.
[0018] This movement can be carried out actively and/or passively.
In this context, "passively" means that the movement is brought
about only by the pressure or pressure forces that are present in
the cartridge or film pack at the end of a dispensing stroke. The
term "actively" means that the movement is caused by a force which
does not come from the cartridge or film-pack system itself, but
rather, which was exerted during the previous dispensing procedure
in addition to the force needed to dispense the compound contained
in the pack. An active movement is achieved in that, during the
dispensing procedure, the advancing mechanism is at first at a
certain distance from the receptacle for the pack and it has to be
moved in the direction of the receptacle by means of the exertion
of force. This is the case, for example, when a mechanism is
provided between the advancing mechanism and the receptacle for the
pack, so that when the advancing mechanism is pressed against the
receptacle for the pack, said mechanism builds up a counterforce in
order to press the two parts away from each other again after the
dispensing stroke. Once the dispensing procedure has been
completed, due to the relaxation of the previously applied
additional force, that is to say, the counterforce, the advancing
mechanism is actively pushed back opposite to the direction in
which pressure is exerted. As an alternative, the advancing
mechanism can be configured in such a manner that its return
movement takes place without the exertion of additional force, so
that the return movement is passive, exclusively due to the force
stemming from the pack. Moreover, the movement can take place
analogously to the active movement, whereby the advancing mechanism
is arranged with respect to the receptacle in such a way that, in
addition to the active movement, a passive return movement takes
place, that is to say, caused by the pressure force that might
still be present in the pack.
[0019] However, since the extra work for the user during the next
dispensing procedure has to be minimized, the return stroke should
only constitute part of the total dispensing stroke. For this
reason, the movement path of the return stroke is preferably
limited. Owing to this partial force relief or pressure relief in
the pack used for the dispensing procedure, afterflow of the mortar
can be reduced to such an extent that afterflow of compound is
negligible or non-existent and, in the case of multi-component
systems, there are no longer any disruptions of the mixing and
curing of the compound dispensed from the mixing element.
[0020] Moreover, the expenditure of force in the system for
purposes of moving the advancing mechanism opposite to the
direction in which pressure is exerted has to be kept so small that
the system can be relieved via the return stroke of the advancing
mechanism rather than in the dispensing direction via the outlet
opening of the pack and thus into the mixing element. For this
reason, it is preferable for the movement path of the advancing
mechanism as well as for the force required for the return stroke
to be adjustable. In this manner, the return stroke can be
controlled as a function of the system properties such as
compressibility and dynamics (spring-damper behavior) and can
therefore be kept as small as possible.
[0021] In the case of multiple-component compounds, for instance,
which are only mixed with each other when they are dispensed out of
the pack into a mixing element connected to the pack such as a
static mixer, the dispensing forces and correspondingly the force
relaxation after a dispensing procedure are relatively high,
particularly in the case of pasty compounds. Consequently, a higher
force can also be set for the return stroke. In the case of
lower-viscosity compounds, the force for the return stroke has to
be set correspondingly lower. The force needed to return the
advancing mechanism to the initial position at the end of the
dispensing stroke by relaxing the system must not be too high and
should not require a noticeably higher force expenditure on the
part of the user during the dispensing procedure. Advantageously,
the movement force is set so low that it is independent of the
system-related dispensing forces.
[0022] The advancing mechanism here can be provided in a component
of its own, such as, for example, a housing.
[0023] Preferably, the advancing mechanism and the receptacle for
the pack are joined together by a decoupling element (mechanical
decoupling). The decoupling element is configured in such a way as
to result in a path-controlled and force-controlled movement of the
advancing mechanism and thus of the at least one piston rod
opposite to the direction in which pressure is exerted. The
decoupling element is not restricted. It merely has to be designed
in such a way as to allow an active and/or passive movement of the
advancing mechanism. Moreover, the decoupling element can be such
that a path-controlled and/or force-controlled movement of the
piston rod is ensured. Examples of decoupling elements are a
carriage system, a disc spring or a plastic damper, or else a
combination thereof.
BRIEF DESCRIPTION OF THE DRAWING
[0024] The invention will be described in greater detail below on
the basis of an embodiment. The following is shown:
[0025] FIG. 1: a schematic top view of a dispenser according to the
invention.
DETAILED DESCRIPTION
[0026] The dispenser 1 shown in FIG. 1 has a receptacle 2 for a
cassette into which a pack having two film pouches arranged in
parallel is inserted. The piston rods 3 for dispensing the
compounds contained in the pack or in the cartridge are situated on
the advancing mechanism 4 that is joined to the receptacle 2 by
means of two decoupling elements in the form of damping elements 5
such as, for instance, plastic dampers. The damping elements 5
ensure the path-controlled and/or force-controlled return stroke of
the advancing mechanism 4 along with the piston rods 3 for purposes
of relieving the pressure or force in the pack.
[0027] In order to dispense the compounds from the pack, the piston
rods 3 are moved axially via a schematically-shown clamping
mechanism 14 in the direction of the receptacle 2 by actuating a
lever on the advancing mechanism 4. In this process, the damping
elements 5 are compressed so that first of all, the entire
advancing mechanism is moved in the direction of the receptacle 2,
as a result of which the advancing mechanism 4 is moved out of a
first position into a second position. The distance that has to be
travelled during the stroke can be set by means of the damping
element itself, by the material properties, by the size and
thickness, relative to the advancing direction of the piston rod.
Once the advancing mechanism 4 is no longer resting movably on the
receptacle 2, the further stroke movement of the anchor rods 3
causes a further rise in the force or pressure in the pack used in
the dispensing procedure, thus causing the compound to flow out
into the static mixer.
[0028] After the dispensing stroke has been completed and after the
lever has been released, the damping elements 5 press the advancing
mechanism 4 in the direction opposite to the dispensing direction,
that is to say, away from the receptacle 2, for example, as a
result of which the advancing mechanism with the piston rod is once
again moved out of a first position (previously the second
position) into a second position (previously the first position).
As a result, the pressure in the pack used for the dispensing
procedure can be relieved partially directly and afterflow of the
compounds contained in the pack for relieving the pressure and
force can be prevented or minimized. The magnitude of the return
stroke, in other words, the movement path opposite to the
dispensing direction, is determined on the basis of the properties
of the damping element 5. When elastic plastic dampers 5 are used,
the distance of the return stroke can be greater than the thickness
of the plastic dampers, so that an additional force relaxation of
the system can be achieved passively. This effectively prevents
afterflow of the compounds contained in the pack.
* * * * *