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Description  |
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FIELD OF THE INVENTION
The present invention relates to a replaceable caulking tip for use on
caulking cartridges and the like, and a method of forming the caulking
tip.
BACKGROUND OF THE INVENTION
This is a continuation-in-part of U.S. patent application, Ser. No.
884,047, filed July 10, 1986 and now abandoned.
A wide variety of caulking cartridges has long been employed for use in a
number of applications. These cartridges are commonly used in caulking
guns for applying caulking material in joints either to seal the joints,
to improve their esthetic appearance and/or prior to painting.
One common example of a replaceable caulking cartridge and caulking gun is
illustrated in FIG. 1 of the accompanying drawings and is described in
greater detail below. In any event, since each cartridge is used only for
a short time, they are generally formed with a tubular nozzle of
relatively thin and soft material, usually plastic. Normally, the user
cuts off the end of the tubular nozzle to form an opening through which
caulking material is ejected from the cartridge.
In most applications, the user moves the cartridge along a joint to be
caulked for applying a continuous bead of caulking material. In most
applications, it is desirable that the bead be formed with a continuous
configuration for esthetic purposes. Usually, a coating of paint or the
like is applied over the bead so that the configuration of the bead
remains clearly apparent.
In applications of the type particularly contemplated by the present
invention, the joint is formed between angularly aligned surfaces, for
example, between wallboard or other wall surfaces and trim such as doors,
windows, etc.
In various applications such as painting houses or other buildings, large
numbers of cartridges are used and it is important that the user be able
to apply a continuous bead as noted above in a rapid manner while using up
substantially all of the caulking material available from each cartridge
for purposes of economy.
Accordingly, there has been found to remain a need for improved tips for
use on such cartridges to apply the caulking material. As noted above, a
great number of designs for caulking guns and the like have been made
available in the prior art. For example, U.S. Pat. No. 3,121,516 issued
Feb. 18, 1964 to De Wees et al disclosed a cartridge and caulking gun
combination including a discharge control device or nozzle formed
integrally with the cartridge.
With the nozzle being tapered, it could be cut off at any point along its
length by the user depending, for example, upon the size of bead desired.
However, since the nozzle was intended only for use during the life of the
cartridge, it was formed from a relatively soft, thin plastic material.
For that reason, the nozzle tended to become abraded or roughened at its
outlet orifice, interfering with subsequent smooth bead formation. The
roughened or abraded tip of the nozzle tended to cause skipping and
undesirable discontinuities in the bead being formed
U.S. Pat. No. 3,188,057 issued June 8, 1965 to Trumbull disclosed yet
another caulking device wherein the nozzle was separately formed from and
threaded onto the cartridge to form an outlet for caulking material.
However, that nozzle otherwise appeared to have the same limitations
referred to above.
Other examples of caulking devices were also disclosed in U.S. Pat. Nos.
3,058,632; 3,076,225; 3,439,839; 3,997,085 and 4,311,258. However, the
caulking tips provided in those patents were also generally similar to
those referred to above and that shown in FIG. 1 of the accompanying
drawings and described in greater detail below.
The wall surfaces contacted by the nozzle or tip during application of the
caulking material also present a particularly severe condition for the
tip. The present invention particularly contemplates caulking in joints
formed between angularly aligned surfaces. For example, it is necessary or
desirable to caulk joints formed between the wall surfaces and trim
including doors, windows and the like. In such applications, the walls are
typically formed from wallboard and are covered with taping compounds, or
texturing material or other material applied to the wallboard or sheetrock
before caulking of the joints noted above. The above compounds typically
include sand or other highly abrasive materials. Accordingly, they tend to
cause very high wear rates on normal caulking tips of the type referred to
above.
There has been found to remain a need for an improved replaceable tip to
facilitate application of caulking material in joints and elsewhere while
facilitating formation of a smooth bead of caulking material.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an improved
replaceable caulking tip for overcoming one or more problems of the type
referred to above.
Furthermore, it is an object of the invention to provide a replaceable
caulking tip having an outlet orifice formed with substantial body
material surrounding the orifice to permit shaping of the tip about the
periphery of the orifice, the orifice being elongated and inclined about
12 to 20 degrees, more preferably about 15 to 17 degrees, from a plane
perpendicular to a longitudinal axis of the tip to facilitate caulking
operations.
In order to provide substantial body material surrounding the orifice, as
described above, at least an end portion of the body forming the orifice
with an annular wall thickness of at least about 0.015 inches. Preferably,
the wall thickness is in the range of about 0.015-0.060 inches, more
preferably in the range of about 0.020-0.030 inches, the wall thickness
for any particular tip also being dependent upon the orifice size.
Specific wall thicknesses for different orifice sizes are discussed in
greater detail below.
It is a particularly important feature of the invention to provide the
combination of (1) the orifice being elongated, (2) the orifice being
inclined as noted above, and (3) the body material surrounding the
periphery of the orifice being rounded or faired. After substantial
experimentation, it was found that these three features in combination are
essential in the formation of a desirably caulked joint of the type
contemplated by the invention. In particular, the angular alignment of the
orifice is necessary to facilitate an operator being able to caulk a
joint, for example, from ceiling to floor, in a single stroke. At the same
time, the elongated configuration of the orifice and the faired body
material about the orifice cause the tip to be self-wiping so that very
smooth bead is formed along the entire length of the joint without the
need to wipe the joint in a separate operation.
Yet another important feature of the invention is to assure that the
longitudinal axis of the elongated orifice is parallel with the axis of
inclination for the orifice. In other words, during use of the tip, it is
desirable that the elongated orifice be positioned so that its
longitudinal axis is parallel to the joint being caulked and the direction
of travel for the tip along the joint. This same relationship is also
necessary for the axis of inclination for the orifice.
It is yet a further object of the invention to provide a replaceable
caulking tip of the type referred to immediately above wherein the body is
formed of a material having suitable composition and hardness for
resisting or minimizing wear during repeated use of the tip and for
permitting initial forming of the tip and reshaping if necessary
Accordingly, characteristics of the body material including composition
and hardness are also important together with the three features discussed
above. At the same time, the material of the body must be selected to
facilitate economical formation of the tip during manufacture. Yet another
related feature of the invention is selection of the material forming the
tip so that it does not leave an undesirable mark along the joint being
caulked.
Preferred materials for meeting the various objects set forth above are
described in greater detail below. Generally, it has been found desirable
to employ a metal having a Rockwell Hardness in the range of about B75 to
about B95. However, the composition of the tip is equally important.
Preferably, the invention contemplates the use of either low carbon or
medium carbon steels which are preferably cold drawn to provide both the
necessary hardness or wearability and yet be machinable.
It is yet another object of the invention to provide a method for forming
the tip to assure proper interaction of the various features noted above.
The method comprises the steps of forming a tubular body of a selected
material, providing indexing means on the tubular body to assure proper
angular alignment of the body during subsequent steps, grinding or cutting
the inclined surface of the tip orifice, elongating the orifice, for
example, by a crimping operation, the indexing means being employed during
both the inclining and elongated steps, and then shaping the orifice
periphery to form a rounded or faired configuration.
Additional objects and advantages of the invention are made apparent in the
following description having reference to the accompanying drawings
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view in elevation of a prior art caulking gun and
cartridge.
FIG. 2 is an enlarged side view in elevation of a replaceable caulking tip
according to the present invention, the caulking tip being engaged upon
the nozzle of a cartridge such as that illustrated in FIG. 1 with only a
portion of the nozzle being shown.
FIG. 3 is a view taken along section line III--III of FIG. 2, FIG. 2 in
turn being a view taken along section line II--II of FIG. 3.
FIGS. 4 and 5 are views respectively taken along section lines IV--IV and
V--V of FIG. 3.
FIG. 6 is an end view of the threaded portion of the caulking tip of FIG.
5.
FIG. 7 is a fragmentary view of an end portion of the caulking tip
including the orifice together with a cap.
FIG. 8 is a block diagram illustrating a preferred method for forming the
caulking tip of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and particularly to FIGS. 2-5, a replaceable
tip is generally indicated at 10 for use on caulking cartridges and the
like to facilitate the smooth deposit of caulking material and to allow
repeated use of the caulking tip over extended periods of time.
In order to better illustrate the manner of use contemplated for the
replaceable caulking tip 10, a prior art cartridge 12 and caulking gun 14
are shown in FIG. 1. Referring to FIG. 1, the cartridge 12 fits within the
caulking gun 14 which can be operated by a trigger 16 for causing a
plunger 18 to move through the cartridge 12 with caulking material being
ejected through a tapered nozzle 20.
The tapered nozzle 20 is generally formed of relatively thin, soft plastic
so that it can be cut off at any point along its length to form an outlet
orifice of varying size. For example, the closed end of the nozzle 20 may,
for example, be cut off along the line indicated at 22 in order to allow
caulking material to be ejected through the nozzle. However, the plastic
material forming the nozzle would be subject to rapid wear as noted above
and would thereafter tend to interfere with the formation of a smooth,
continuous bead of caulking material
The present invention has eliminated that problem by providing the
replaceable caulking tip 10. As may be best seen in FIGS. 4 and 5, the
caulking tip 10 has an elongated hollow body 24 formed from relatively
hard material, preferably metal but possibly also hard plastics or the
like. At the same time, the material of the body 24 is selected so that it
can be filed or otherwise worked in order to permit initial formation of
the various features of the caulking tip and restoration of the rounded
periphery of the orifice as described in greater detail below.
One end 26 of the body 24 is formed with internal threads 28 so that the
body can be threaded onto an outlet nozzle for a cartridge such as the
nozzle 20 illustrated in FIG. 1. In this regard, the tip is self-threading
with the internal threads 28 tending to deform or cut through into the
plastic nozzle. In any event, the internal threads 8 are effective for
assuring engagement of the caulking tip onto the outlet nozzle.
A fragmentary portion of the nozzle 20 is illustrated in FIG. 2 to
demonstrate the manner in which the replaceable tip 10 is mounted
thereupon. The internal threads 28 also permit the caulking tip 10 to be
removed from the nozzle 20 after the supply of caulking material from the
cartridge 12 has been exhausted. Thereafter, the replaceable caulking tip
10 may similarly be used with one or more additional cartridges.
The body 24 of the tip 10 is formed with an internal passage 30 along its
length terminating at an outlet orifice 2 formed on the opposite end 34 of
the body.
As may be best seen in FIGS. 3-5, the body 24 is formed with substantial
body material about the periphery of the orifice 32 to facilitate
formation of a rounded or faired shape 36 about the periphery of the
orifice 32. The caulking tip 10 may be supplied with the body material
being rounded or faired about the orifice or with a relatively blunt end
so that the user may taper or round the body material about the orifice as
desired.
Generally, it has been found that the body 24 adjacent the orifice 32 must
have an annular wall thickness of at least about 0.015 inches in order to
permit proper shaping about the orifice. More preferably, it is
contemplated that the body 24 adjacent the orifice has an annular wall
thickness in the range of about 0.015-0.060 inches, more preferably in the
range of about 0.020-0.035 inches. However, the particular thickness for
any given tip depends at least in part upon the size of the orifice. Only
for purposes of illustration, it is noted that caulking tips have been
formed with inside diameters in the range of from 0.0938 inches to 0.1875
inches. For that range of inside diameters, the wall thickness preferably
vary from about 0.020 to about 0.030 inches.
As noted above, the orifice 32 is inclined about 12 to 20 degrees, more
preferably about 15 to 17 degrees, from a plane 38 perpendicular to the
longitudinal axis of the caulking tip 10 and accordingly the cartridge 12
of FIG. 1.
At the same time, the orifice 32 is formed with an elongated configuration
as best illustrated in FIG. 3. In other words, the orifice 32 is formed
with a dimension illustrated in cross section in FIG. 4 which is
substantially greater than the dimension for the orifice illustrated in
cross section by FIG. 5. Typically, the orifice is elongated, for example,
by crimping or similar shaping, so that the longitudinal dimension of the
elongated orifice is approximately 50% to 100% greater than the lateral
dimension of the elongated orifice.
It has also been found necessary to assure proper alignment of the
elongated orifice relative to the angle of inclination for the orifice 32
as illustrated in FIG. 4. The angle of inclination for the orifice is
arranged substantially parallel or co-linear with the axis of elongation
for the orifice. In this regard, the axis of inclination is indicated at
42 in FIG. 4 while the axis of elongation for the orifice is indicated at
44 in FIG. 3.
The caulking tip 10 is also preferably formed with an enlarged flange or
projection 40 which is knurled or otherwise roughened to permit the user
to more easily grip the caulking tip 10 and thread it into place on the
nozzle.
In order to assure proper angular alignment of the tubular body during
various steps of the methods for forming the tip, an indexing notch 46 is
formed on the one end of the tubular body adjacent the internal threads
28. The manner in which the notch is used during manufacturing is
described in greater detail below.
Substantial experimentation was necessary to determine a preferred metal
for forming the tubular body of the caulking tip. As noted above, the
composition and hardness of the body was selected to assure durability of
the tip even in engagement with abrasive surfaces as described above. At
the same time, it was necessary to maintain workability in order to permit
proper initial formation of the tip and to permit the tip to be restored
during use if necessary
Certain metals such as brass and aluminum are commonly considered for
applications where machining is necessary. However, tips formed from these
metals were found to exhibit excessive wear and also to leave undesirable
marks on the joint surfaces. Similarly, metals containing substantial
quantities of lead were found to be undesirable because of a tendency to
mark the joint surfaces.
Although these shortcomings could be overcome, for example, by hardening
the metals, it was found preferable to employ certain steel alloy
compositions having a general Rockwell Hardness in the range of about B75
to B95. Such a range of alloys, termed generally medium carbon or low
carbon fields, were found to be available from LaSalle Field Company under
the type designations "1018", "1117", "1045", "1141", "1144", "1215" and
"12L14". These metals were further characterized as being cold drawn.
Certain of the alloy compositions noted above were less desirable than
others. For example, the alloy indicated as type 1117 included higher
amounts of lead and was found to be satisfactory in performance but tended
to leave a mark on the joint surfaces. Similarly, the other compositions
illustrated one or more advantages or shortcomings.
The alloy indicated as type 12L14 was found to be superior in that it
exhibited desirable hardeners and durability while also being more readily
machinable than the other alloys. Thus, this alloy was found not only to
produce a superior tip but also to permit more rapid manufacture of the
tip. The composition indicated as type 12L14 was further identified as
having a Rockwell Hardness of B85. In addition, this alloy was categorized
as a leaded, resulphurized and rephosphorized low carbon steel. Generally,
the type designations noted above are also standards for AISI/SAE.
The manner of use for the caulking tip 10 is believed apparent from the
preceding description but is described briefly below in order to assure a
more complete understanding of the invention.
Initially, with the replaceable caulking tip 10 used on a cartridge such as
that indicated at 12 in FIG. 1, the tapered nozzle 20 is first cut off,
for example, along the line 22 to allow caulking material to flow out of
the cartridge.
The caulking tip 10 is then threaded onto the nozzle as illustrated in FIG.
2 with the internal threads 28 serving to engage the tip upon the nozzle
20. With the caulking tip in place, a user can then employ the caulking
gun 14 of FIG. 1 or any other caulking device in a generally conventional
manner. However, the configuration of the caulking tip 10 particularly
facilitates the caulking operation and formation of a smooth caulked
joint. In particular, it is noted again that the combination of the
elongated orifice, inclination of the orifice and the fairing about the
orifice all contribute to permit caulking of relatively long joints in a
single stroke without the need to wipe the joint in a separate step
The tip 10 also has greater versatility because of the elongated orifice
32. Although it is preferred to employ the tip with the axes of elongation
for the orifice and the axis of inclination for the orifice both being
parallel to the joint, it is also possible for a user to employ the tip
with the longitudinal axis of the orifice perpendicular to the joint. Such
a technique may be useful in special circumstances, for example, to
effectively vary the width of a bead formed in the joint.
Furthermore, after caulking material is exhausted from each cartridge such
as that indicated at 12 in FIG. 1, the caulking tip 10 may be rapidly
removed and similarly replaced on a substitute cartridge so that the
caulking operation can be continued.
If the caulking tip 10 exhibits wear or erosion about the orifice 32, the
user can reconfigure the rounded or faired shape of the body about the
orifice, for example, by means of a file or rasp (not shown). In that
manner, he can readily reform the desired configuration of the tip, making
it useful over longer periods of time.
Operation of the caulking tip is further enhanced by the provision of a
flexible cap 48 which is adapted to fit over the orifice end of the tip.
Thus, the cap 48 may be installed on the tip during periods of nonuse to
prevent caulking material within the tip from hardening. Thus, when a user
is ready to recommence caulking operations, he may merely remove the cap
48 and continue. This of course avoids the need for cleaning caulking
material from the tip during periods of nonuse. Also, when the cap 48 is
not being used on the tip as illustrated in FIG. 7, it is also sized so
that it can be stored on a portion of the caulking gun. Referring for
example to the caulking gun 14 in FIG. 1, the cap 48 may be stored if
desired on the exposed end of the plunger 18.
In manufacture, the tubular body of the caulking tip is first formed with
the tapered configuration illustrated in the drawings. As can be seen from
FIGS. 4 and 5, the hollow body which forms the caulking tip is a single
piece of material so that the caulking tip has a unitary structure.
According to the present invention, the indexing notch 46 is then formed
in the one end of the tubular body. Thereafter, the 15 degree angular
inclination illustrated in FIG. 4 is formed, for example, by grinding or
cutting with the indexing notch 46 being employed to establish a selected
angular alignment of the tubular body relative to the axis of inclination
42. The orifice is then elongated, for example, by crimping or similar
shaping. Here again, the indexing notch 46 is employed to assure proper
angular alignment of the tubular body so that the axis of elongation 44
for the orifice is parallel or co-linear with the axis of inclination 42.
Thereafter, the periphery of the orifice is shaped to have the rounded or
faired configuration described above. In this manner, a superior caulking
tip is formed having the unique combination of features described above.
It will also be noted from the above description and the drawings,
particularly drawings 3, 4, and 5, that the caulking tip has a
longitudinal axis along the length of the tubular body and the outlet
orifice has an elongated planar configuration wherein the orifice has a
greater dimension in one direction than in the other, thereby forming an
axis of elongation. It will also be apparent that the axis of elongation
is on a line which is inclined from a plane perpendicular to the
longitudinal axis and the orifice has two sides (50) which are
substantially parallel to each other and to the axis of elongation.
There has thus been disclosed a particularly advantageous replaceable
caulking tip having numerous features making it particularly useful for
caulking operations Variations and modifications in addition to those
suggested above are believed apparent Accordi | | |
