Note: Descriptions are shown in the official language in which they were submitted.
1'~9~
FIXTURE FOR SECURING AN ADHESIVE
ATTACHMENT TO A SUBSTRATE
BACKGROUND OF THE INVENTION
This invention relates generally to adhesive
attachment assemblies or fixtures and related methods
for securing an adhesive attachment or the like onto a
supporting surface or substrate. More specifically,
this invention relates to improvements in such adhesive
attachment assemblies or fixtures particularly of the
type described and claimed in commonly assigned U.S.
Patents 4,302,492; 4,338,151; and 4,390,576.
In many instances, it is necessary or
desirable to attach an element such as a patch,
threaded screw stud, or the like onto a supporting
substrate by means of an adhesive connection or bond.
For example, it may be necessary to apply a thin patch
to the skin of an airc;-aft or the hull of a boat to
repair a hole therein. Alternately, it may be
desirable to mount a threaded screw or other device
onto a substrate such as the windshield of an
automobile without requiring a hole to be made in the
substrate. As another alternative, in many modern
aerospace applications, it is ~requently desirable to
attach a threaded stud or the like onto a nonmetallic
substratQ without forming a hole or otherwise
interrupting the substrate, wherein the stud provides a
mounting implement for items such as a cable clamp,
etc. In many such cases, it is necessary for the
attachment to be located on the substrate with
relatively high precision and further that a positive
force be applied urging the attachment against the
s~lbstrat~ for et l~st some minimum initial time
-2- 1~9Z8t 2
period to allow, for example, curing of an adhesive
material to aehieve a relatively secure bond with the
substrate.
In the past, many different clamp and fixture
deviees have been proposed for use in temporarily
holding an adhesive attachment on the surface of a
substrate during the cure time of an adhesive
material. The majority of such clamp and fixture
devices have required some form of mechanical
connection to the substrate by means of screws or other
mechanical fasteners, clamping ~aws, etc. However,
these deviees are not suited for use with extended
surfaee areas or fragile or thin-walled substrates
within whieh surfaee interruptions to aecommodate
mechanical fastening are not possible or are
undesirable. Other fixturing devices have been
proposed which rely upon suction cups for holding an
attachment in position cn a substrate, but suction cup
deviees are limited to use with substrates having
smooth surfaee finishes and further funetion to retain
the attachment in place without exerting significant
positive forees urging the attachment against the
substrate. As a result, with suction cup deviees, the
adhesive material on the substrate ean be unevenly
distributed and/or eure with less than optimum bonding
strength. Still other proposed deviees utilize
inflatable air bags or bladder0 held adhesively onto
the substrate to bear against an attaehment, but sueh
flexible bladdQrs also lack the requlsite structural
integrity to apply a uniform foree to the attaehment
and thus do not prevent uneven distribution of a
bonding agent at the attachment/substrate interface.
Improved devices are described ~nd claimed in
commonl~ assigned u.S. Patents 4,302,492; 4,338,151;
and 4,390,576. More particularly, these patents
disclose attachment devices having a support fixture
for temporarily securing to the substrate by means of a
-3- 1~ 2
pressure-sensitive adhesive or the like and force-bias
or spring means for applying a force urging an
attachment into positive bearing engagement with the
substrate. The support fixture or a component thereof
is movable between a first position with the adhesive
attachment substantially out of bearing engagement with
the substrate to a second position with the attachment
pressed against the substrate. An over-center type
annular spring plate constitutes the movable component
in most of the described embodiments.
The present invention relates to further
improvements in adhesive attachments and mounting
fixtures therefor. More specifically, the present
invention relates to improved relatively simple, and
relatively cost-efficient adhesive attachments and
fixtures therefor, wherein a fixture can be formed
substantially as a one-piece construction of molded
plastic or the liXe, wherein the fixture may include
means for orienting an attachment device during
movement into engagement with a substrate, and wherein
the fixture can withstand relatively high temperature
environments.
SUMM~RY OF THE INY~NTION
In accordance with the invention, an improved
fixture is provided for quickly, easily, and accurately
securing an attachment onto a substrate by means of an
adhesive or the like. The fixture comprises a support
frame adapted for high volume, relatively low cost
production as a one-piece component, for example,
molded plastic. The support frame is associated with
connector means C~l~h as a pressure sensitive ~dhesive,
for temporary securement to the substrate and includes
retainer means for releasably carrying the attachment
to be applied to the substrate. The support frame ls
movable from a first position in which either the
_4_ 12~ 2 ~6
attachment or the fixture is substantially out of
engagement with the substrate to a second position with
the fixture adhered to the substrate and urging the
attachment with a positive force into firm bearing
contact with the substrate.
In one preferred form of the invention, the
support frame comprises an outer support cylinder
having a radially oriented flange at one end coated
with a pressure-sensitive adhesive or the like for
temporary securement to the substrate. The outer
support cylinder is joined integrally by a plurality of
spokes with an inner, preferably coaxial pressure
sleeve, wherein the spokes project radially inwardly
from the outer support sleeve and angularly in an axial
direction away from the flange. The pressure sleeve in
turn carries the retainer means which, in one form,
comprises an inwardly radiating, yieldable annular lip
for releasably supporting an attachment, such as a
threaded screw, having an enlarged footplate to be
adhesively attached to the substrate.
In use, an appropriate adhesive material is
applied to the underside of the attachment footplate,
and/or to the substrate, and the flange on the outer
support cylinder is temporarily adhered to the
substrata. The pressure sleeve is then pressed axially
toward the substrate to move the spokes past an
over-center condition thereby displacing the attachment
from a first position substantially out of bearing
contact with the substrate to a second positon with the
underside of the footplate engaging the substrate. The
outer support cylinder and/or the pressure sleeve
deform slightly from a cylindrical configuration during
this movemen~ but return elastically to substantially
cylindrical qeometries when the second position is
reached to provide hoop stresses to the spokes for
urging the attachment with a positive force toward the
substrate.
~5~ ~ 86Z
Orientation of the attachment can be
maintained relative to the substrate by maintaining
sleeve orientation within the support cylinder during
pressure sleeve movement toward the second position.
More particularly, the support frame may further
include guide means spaced axially from the spokes for
cooperation with the spokes to maintain the pressure
sleeve coaxially within the support frame. In one
preferred form, the guide means comprises a second
plurality of spokes which are desirably offset
angularly relative to the remaining spokes to
facilitate molding of the support frame as a one-piece
component. Alternate guide means may include spacer
fins or the like for maintaining coaxial spacing
between the outer support cylinder and the pressure
sleeve.
After the adhesive material has cured
sufficiently, the support frame is removed Erom the
substrate with the attachment releasing from the
retainer means to remain in place on the substrate. In
one form of the invention, support frame removal ls
facilitated by a score formed in the connector flange
and associated with a pull t~b sized for easy grasping
and twisting motion to separate the connector flange
from the substrate.
In accordance with further features of the
invention, the improved fixture can be manufactured
conveniently in multi-fixture ma~azines or continuous
rolls with interconnecting runners to provide a
plurality of fixtures which can be advanced serially to
an installation head of automated or power-driven
installation equipment. That is, the fixtures can be
a~v?lncec~ automatically or semi-automatically into
operative relation with a punch designed to separate
the fixtures in sequence ~rom the runners and to mount
each fixture onto a substrate, followed by displacment
of the pressure sleeve to advance the attachment into
l~Z~t Z
--6--
positive substrate engagement.
In another preferred yet simplified form, the
mounting fixture comprises a dished central spring member
or spring plate for carrying an adhesive attachment, and
a connector rim at the periphery of the spring member
carries adhesive means for at least temporary connection
thereof onto the substrate. In use, the adhesive
attachment assembly including the attachment and mounting
fixture are displaced by an installation tool toward the
substrate, with the spring member disposed in an in
unstressed or normal position carrying the adhesive
attachment in a position leading the connector rim for
placing the attachment onto the substrate prior to the
connector rlm. Further advancement of the installation
tool toward the substrate applies a force acting through
the attachment to deflect the spring member to a
secondary, stressed position while the installation tool
moves the fixture connector rim to at least temporary
adhesive securement onto the substrate. Such securement
of the connector rim functions to maintain the spring
member in the secondary, stressed position wherein the
spring member applies a positive force pressing the
attachment toward the sub~trate for optimum bonding
strength of a selected bondin~ agent at the
attachment/substrate interface. ~he installation tool
may include heat input means, vibratory means, or
rotational means for activatlng the selected bonding
agent concurrently with attachment placement onto the
substrate.
Other features and advantages of the present
invention will become more apparent from the following
detailed description, taken in conjunction with the
accompanying drawings which illustrate, by way of
example, the principles of the invention.
'X
1~:9~B62
-- 7
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the invention.
In such drawings:
FIGURE 1 is a perspective view illustrating the top
S and one side of an improved attachment fixture embodying,
in one form, the novel features of the invention;
FIGURE 2 is a perspective view showing the bottom
and one side of the attachment fixture of FIG. l;
FIGURE 3 is a perspective view illustrating a
threaded screw attachment secured onto a substrate;
FIGURE 4 is a fragmented vertical section
illustrating the fixture of FIG. 1 temporarily mounted
onto a substrate with a threaded screw attachment
carried in a first position substantially out of bearing
engagement with the substrate;
FIGURE 5 is a fragmented vertical section similar to
FIG. 4 but illust.rating the fixture in a second position
with the attachment urged into bearing engagement with
the substrate;
FIGURE 6 is a fragmented horizontal section taken
generally on the line 6-6 of ~IG. 4;
FIGURE 7 is a vertical sectional view simi.lar to
FIG. 5 but illustrating removal oE the fixture from the
substrate and the attàchment;
FIGURE 8 is a perspective view similar to FIG. 1 but
illustrating one alternative form of the invention;
FIGURE g is a vertical sectional view similar to
FIG. 4 but illustrating another alternative form of the
invention;
FIGURE 10 is another vertical sectional view similar
to FIG. 4 but illustrating a further alternative form of
the invention;
FIGURE 11 is a plan view illustrating a
X
-8- ~928~iZ
plurality of the fixtures of FIG. 1 interconnected by
runners as a continuous molding;
FIGURE 12 i8 a diagrammatic view illustrating
one ~orm of an installation head for automated or
power-tool installation of fixtures onto a substrate;
FIGURE 13 is an enlarged fragmented
elevational view illustrating a portion of the
installation head of FIG. 12, and further depicting
operation of the head for installing one of the
fixtures onto the substrate;
FIGURE 14 i5 a perspective view illustrating
an adhesive attachment assembly including a mounting
fixture embodying another alternative form of the
invention;
F~GURE 15 i5 a somewhat schematic diagram
depicting use of the mounting fixutre of FIG. 16 and an
associated installation tool for mounting an adhesive
attachment onto a substrate;
FIGURE 16 is a schematic diagram similar to
FIG. 15 but showing the adhesive attachment assembly
mounted upon the substrate;
FIGURE 17 is an enlarged sahematic diagram
similar to FIG. 15 and depicting a modified
installation tool for use with a hot melt adehesive at
thQ attaahment/substrate inter~ace;
FIGURE 18 is another schematic diagram similar
to FIG. 15 but illustrating permanent attachment of the
adhesive attachment assembly onto a eubstrate:
FIGURE 19 is an enlarged perspective and
somQwhat diagrammatic view illustrating an adhesive
attachment having an encapsulated bonding agent on the
underside thereof;
FIGURE 20 is an enlarged fragmented sectional
and somewhat diagrammatic view generally corresponding
with the encircled region 20 of FIG. 19;
FIGURE 21 is an enlarged fragmented sectional
and somewhat diagrammatic view similar to FIG. 20 but
l~t28~2
g
illustrating use of an alternative bonding agent;
FIGURE 22 is a schematic cliagram similar to FIG. 17
and illustrating another modified installation tool
including vibratory means for activating a bonding agent;
and
FIGURE 23 is a schematic diagram similar to FIG. 17
depicting still another modified installation tool having
a rotational means for activating a bonding agent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the exemplary drawings, an improved
attachment fixture referred to generally by the reference
numeral 10 is provided for quickly, easily, and securely
mounting an adhesive attachment 12 (FIGURE 3) onto a
substrate 14. The improved fixture 10 is designed for
temporary mounting onto the substrate 14 with the
attachment 12 initially supported in a first position
away from substantial bearing engagement with the
substrate, whereupon a portion of the fixture 10 is
movable quickly and easily to a second position carrying
the attachment 12 into and ur~ed with a positive force
toward substantial bearing engagement with the substrate.
The fixture securely holds the attachment 12 against the
substrate or the cure time o an adhesive material at
the attachment/substrate interace, after which the
fixture is removable quickly and easily to leave the
attachment securely in place.
~'he improved attachment fixture 10 of the present
invention generally corresponds with and improves upon
the attachment fixtures or assemblies described and
claimed in commonly assigned U.S. Patent Nos. 4,302,492;
4,338,151; and 4,390,576. More particularly, the
improved fixture 10 comprises a support frame 16 adapted
for convenient and cost-efficient, high volume
l;~S;'~. Z
-- 10 --
manufacture as a one-piece component, for example, from
molded plastic or the like. In some preferred forms, the
fixture 10 includes means for controlling the orientation
of the adhesive attachment 12 during movement toward the
substrate 14 and throughout the cure period of an
adhesive material to insure substantially optimum
adhesive bonding with the substrate, as will be described
in more detail. Still further, in accordance with the
present invention, the use of foam or resilient pads for
urging the attachment against the substrate may be
avoided, if desired, to permit use of the fixture in
relatively high temperature environments, such as with
autoclave curable adhesives and the like.
The improved attachment fixture 10 is shown in one
preferred form in FIGS 1-7. As shown, the support frame
16 of the fixture comprises an outer support cylinder 18
having a radially outwardly enlarged connector flange 20
at the lower axial end thereof. The illustrative outer
support cylinder 18 and the connector flange 20 are
formed integrally from a relat.ively lightweight molded
plastic, ~uch as polypropylene, polyvinyl chloride,
polyethylene, acetyl copolymers, or any other suitable
plastic material having àt least a minor degree of
structural resiliency. The conslector flange 20 is si~ed
to provide relatively broad surface contact area for
contact with the substrate 14, as will be described, and
can be formed with a thicknes~ to conform readily with
broadly curved or otherwise nonplanar surfaces, for
example, the skin of an aircraft. The underside of the
connector flange 20 is coated with a suitable adhesive
layer 22 particularly such as a layer of a pressure-
sensitive adhesive. A removable sheet of release paper
24 (FIG. 2) is provided as an overlay for the pressure-
sensitive layer 22 and is easily stripped therefrom when
the fixture is ready for use.
12~?~8~2
The support frame 16 of the fixture 10 further
includes an inner pressure sleeve 26 supported generally
coaxially within the outer support cylinder 18. As
shown, this pressure sleeve 26 is connected integrally
with the support cylinder 18 by axially spaced sets of
spokes, with three spokes per set being shown in the
illustrative drawings. More particularly, an upper set
of equiangularly arranged spokes 28 and a lower set of
equiangularly arranged spokes 30 extend between the
cylinder 18 and sleeve 26, wherein the upper set of
spokes is angularly misaligned relative to the underlying
lower set to facilitate molding as a one-piece component.
In the normal position as shown in FIG. 4, the
upper and lower spokes 28 and 30 extend from the support
cylinder 1~ in radially inward directions toward the
pressure sleeve 26 with axial components of direction
extending at least slightly away from the connector
flange 20. Accordingly, each of the spokes 28 and 30 has
a longitudinal length somewhat greater than the radial
distance between the cylinder 1~ and the sleeve 26. In
thls normal position, the spokes 28 and 30 support the
pressure sleeve 26 in a first position with its lower
axial end margin 32 spaced ab~ve the plane of the
pressure-sensitive adhasive layer 22 on the connector
~5 flange 20. Suitable retainer means, such as a compliant
annular ring 34 protruding radially inwardly from the
pressure sleeve 26 is provided to releasably support the
attachment 12, with a threaded screw 36 being shown in
the drawings by way of example. The lower end of this
threaded screw is joined to an enlarged disk-shaped
footplate 38 which is thus retained by the retainer ring
34 normally spaced slightly above the pressure-sensitive
layer 22, or in any event, without substantial bearing
contact with the substrate 14.
In use of the fixture 10, a suitable quantity
f~
- 12 _ 1 ~9Z ~-^Z
of adhesive material 40 such as an epoxy resin or any
other suitable adhesive material, is applied to the
underside of the footplate 38. Alternately, the adhesive
material 40 may be applied directly to a predetermined
location on the substrate 14, or to both the footplate
and the substrate. The fixture 10 is then temporarily
secured onto the substrate 14 at the selected location by
removal of the release paper 24 and by presslng the
connector flange 20 into secure contact with the
lo substrate 14. Durin~ this temporary securement
procedure, the pressure sleeve 26 remains in the first
position, as viewed in FIG. 4, supporting the attachment
footplate 38 spaced from or otherwise out of substantial
bearing contact with the substrate 14.
The attachment 12 is then mounted onto the substrate
quickly and easily by pressing the pressure sleeve 26 in
a direction toward the substrate 14. This motion is
permitted by the somewhat resilient nature of the upper
and lower spokes 28 and 30, and further by similar
resilient structural properties of the outer support
cylinder 18 and/or the inner pressure sleeve 26. More
particularly, during this motion, t.he upper and lower
spokes ~8 and 30 temporarily expand the localized radial
di.mension between the cylinder 18 and pressure sleeve 26
and then move past over center positions to a second
position shown in FIG. S ex~endin~ radially inwardly from
the cylinder 18 with axial components of direction
extending toward the connector flange 20. This movement
of the spokes is facilitated by shaping the spoke
profiles to be relatively thinner at their junctures with
the cylinder 18 and the sleeve 26, and further by
localized deformation of the support cylinder 18 to a
tri-lobe configuration, shown in dotted lines in FIG. 6,
as the sets of spokes move past the over-center position.
The pressure sleeve may also be sized with a wall
thickness to undergo localized deformation as the spokes
move over-center.
X
1~21~2
- -13-
A B the downward pressure sleeve motion
di.splaces the spokes 28 and 30 bevond over-center
positions, the deformed suppGrt cylinder 18 and/or the
pressure sleeve 26 return resiliently to sub~tantially
undeformed cylindrical states. This effectively
applies hoop stresses to the spokes 28 and 30 which
press and maintain the spokes toward the second
position as viewed in FIG. 5. Importantly, these hoop
stresses act through the spokes to similarly press the
pressure sleeve 26 and the attachment carried thereby
with a positive force urging the footplate 38 against
the substrate 14. Retention forces are thus applied to
the adhesive material 40 causing the adhesive material
to spread uniformly and in a relatively thin layer
between the footplate and substrate. The fixture 10 is
allowed to remain in place for a sufficient cure time
while applying and maintaining the positive force
against the attachment.
In accordance with one aspect of the
invention, the upper and lower sets of spokes 28 and 30
cooperate to maintain the pressure sleeve 26 in
generally coaxial alignment throughout pressure sleeve
movement betwe2n the first and second positions. That
is, the set of upper spokes 28 cooperate to maintain an
upper region of the pxessure sleeve 26 in a coaxial
relation to the suppor~ cylinder 18, whereas the three
lower spokes 30 similarly cooperate to maintain a lower
region of the prassure sleeve in a aoaxial orientation
within the support cylinder 18. ~hese dual sets of
spokes thus effectively prevent significant angular
cocking of the pressure sleeve and thereby maintain the
attachment 12 oriented for movement substantially
pert?endiclllarly to the sllbstrate and for footp~te
engagement substantially flush with the substrate.
~hen the second pressure sleeve position is reached,
~le positive force maintaining the footplate against
the substrate is substantially uniformly
- 14 ~'~9'Z8~Z
distributed to insure substantially uniform adhesive
material distribution and cure strength, thereby
providing optimum bonding with the substrate.
Upon sufficient curing of the adhesive material 40,
the fixture 10 can be removed quickly and easily from the
attachment 12 and the substrate 14. More specifically,
with reference to FIG. 7 the fixture 10 can be lifted
manually from the substrate 14 in the direction of arrow
42 to break the temporary adherence between the pressure-
sensitive adhesive layer 22 on the connector flange 20
and the substrate 14. Removal of the fixture 10 is
performed after the adhesive material 40 reaches a
bonding strength exceeding the adherence forces of the
pressure-sensitive layer and further exceeding any
retention forces acting between the retainer ring 34 and
the threaded screw 36. The fixture 10 can thus be
separated from the attachment leaving the attachment in
place on the substrate, as viewed in FIG. 3.
In accordance with one modified form of the
invention, as shown in FIG. 8, the fixture 10 can be
formed with a modified connector flange 20' for
facilitated fixture removal from a substrate after curing
of the adhesive material 40. In this modified form,
which can be otherwise identical with the embodiment
shown in ~lGS. 1-7, the connector flange 20' i5 formed
to include a spiral score 44 of reduced material
thickness leading from the outer periphery of the flange
to a point at or near the periphery of the support
cylinder 18. A pull tab 4G at the outer extent of the
spiral score 44 is not temporarily adhered to the
substrate during fixation of an attachment 12 but is
easily grasped upon adhesive material curing to lift the
connector flange 20' from the substrate 14 as an
elongated strip while tearing the flange along the score
44. The fixture is thus easily removed from the substrate
14 with minimal stresses applied to the substrate,
thereby minimizing risk of damage to the substrate.
- 15 - ~9~8~Z
A further alternative form of the invention is
illustrated in FIG. 9. In this embodiment, a modified
fixture llo includes a support frame 116 including an
outer support cylinder 118 carrying a lower connector
flange 120 and joined integrally by a single set of
preferably three equally spaced inwardly radiating spokes
128 to an inner pressure sleeve 126. A lower retainer
ring 134 on the pressure sleeve 126 carries an
attachment 12, such as a threaded screw 36 with a lower
footplate 38. In the first or normal position, these
spokes 128 extend in the axial direction at least
slightly away from the connector flange 120 to support
the attachment out of substantial bearing contact with
the substrate, all as previously described with respect
to FIGS. 1-7.
In the embodiment of FIG. 9, the underside of the
connector flange 120 supports a ring 48 of resilient foam
or the like which is attached thereto in any suitable
manner, as by use of a pressure-sensitive adhesive
layer. A second pressure-sensitlve adhesive layer 122 is
applied to the underside oE the foam ring 48 and a sheet
of protective release paper 124 conveniently overlies the
layer 122 prior to use. Alternately, the foam ring 48
can be omitted, if desired.
The fixtura 110 is used generally as described with
respect to the fixture 10 by removing the release paper
124 and temporarily adhering the foam ring 48 together
with the connector flange 120 onto a substrate. The
inner pressure sleeve 126 is then pressed toward the
substrate to move the spokes 128 beyond an over-center
condition with the attachment pressed firmly against the
substrate. While the single set of spokes 128 may not
necessarily maintain precise angular orientation of the
attachment relative to the substrate, the support frame
116 is nevertheless adapted for one-piece construction
- 16 ~ Z~62
and will provide sufficient attachment orientation for
many applications.
Still another embodiment of the invention is shown
in FIG. lO, wherein an improved fixture 210 is shown
having a construction corresponding with the fixture 10
in FIGS. 1-7, except that the upper set of spokes 28
(FIG. l) are replaced by alternative guide means for
maintaining the orientation of the pressure sleeve 26
relative to a substrate. More specifically, as shown in
FIG. 10, a set of preferably three equally spaced spacer
fins 50 are formed on the pressure sleeve 26 near the
upper end thereof. These spacer fins 50 have radially
outer edges 50' positioned for close sliding engagement
with the inner surface of the outer support cylinder 18.
Accordingly, the spacer fins 50 maintain an upper region
of the pressure sleeve generally coaxially within the
outer spokes 30 to maintain the pressure sleeve
orientation coaxially within the cylinder 18 during
pressure sleeve movement toward a substrate (not shown in
FIG. 10), as previously described with respect to Figs.
1-7. Alternately, the spacer fins 50 may be formed on
the support cylinder 18 for sliding contact with the
pressure sleeve 26, or substituted into the flxture in
lieu of the lower set of spokes 30 while leaving the
~5 upper spokes ~ intact.
Any one of the fixture embodiments described
hereinabove is adaptable for high volume production, for
example, by chain or roll molding to provide a plurality
of the fixtures interconnected to each other by
lightweight, breakaway runners 60, as viewed in FIG. ll
With respect to a plurality of the fixtures lO. In this
form, the fixtures can be installed in rapid sequence
through the use of automated or semi-automated power tool
equipment.
More specifically, as shown in FIGS. 12 and 13, an
i2
- 17 -
elongated magazine or roll of the fixtures 10
lnterconnected by runners 60 can be fed to an
installation head 62 of an automatic installation
machine, or a manually held power installation tool or
the like. This machine or implement can be provided with
an applicator 64 having a head 65 of any suitable design
for applying adhesive material to the underside of an
attachment carried by each fixture 10 as it is advanced
in succession, for example, by a drive roller 66 or the
like. The fixtures are then advanced further into
association with a two-part punch 68. As shown in FIGS.
12 and 13, an outer punch piece 70 is initially advanced
to push the underlying fixture downwardly through an
opening 72 in a die plate 7~ thereby severing the fixture
from the breakaway runners 60 and pressing the fixture
firmly against a substrate 14. In automated machinery,
the substrate 14 can be carried in turn by suitable
conveyor means (not shown) for appropriate advancement
past the installation head 62.
With the fixture 10 secured onto the substrate, an
inner punch piece 76 can be advanaed, as shown in FIG.
13, to displace the inner pressure sleeve ~G from the
first position to the second pos.ition. This moves the
attachment 12 carried by the pressure sleeve of the
fixture 1~ into engagement with the substrate l~, while
the spokes (not shown in FIG. 13) function to apply a
positive force urginq the attachment firmly against the
substrate for the duration of an adhesive material cure
period.
A further alternative form of the invention is shown
in one preferred form in FIGS. 14-18. As shown, this
mounting fixture 118 comprises a normally dished spring
plate 92 having a central opening 94 for receiving a
threaded stud 36 or other projection on an adhesive
attachment 12 of the general type shown, for example, in
Z86;~
- 18 -
FIG. 3. The spring plate 92, which is preferably formed
from a lightweight molded plastic or the like as a one-
piece component, is joined at its periphery to one axial
end of an annular outer ring 96 which is connected in
turn at its opposite axial end to an outwardly radiating
annular connector rim 98. One face of this connector rim
98 is presented toward a substrate 14 and is lined with
an adhesive material preferably such as a pressure
sensitive adhesive material 100 which may be protectively
covered prior to use by a peel-off release paper (not
shown). Importantly, as viewed in FIG. 15, the underside
surface 130 of the adhesive attachment footplate 38 is
coated with a selected bonding agent 40 and is normally
positioned by the spring plate 92 in a plane advanced
toward the substrate beyond the plane of the connector
rim 98.
The mounting fixture 118 and associated adhesive
attachment are installed quickly and easily onto the
substrate 14 by a modified installation tool 126. More
specif.ically, the tool 126 has a tubular forward end
sized for reception of the ri.ng 96 of the mounting
fixture 118 and for engagin~ the axial face of the
connector rim 98 opposite the adhesi.ve layer 100. The
installation tool 12~ is advanced toward the substrate 1~
in the direction of arrows 10~ in FIG. 15 with the
underside surface 130 of the footplate 38 leading
relative to the adhesive layer 100. ~he attachment
footplate 38 thus lands on the substrate prior to the
connector rim 98 while i.nstallation tool advancement
toward the substrate continues. As a result, the spring
plate 92 is deflected until the connector rim 98 is
secured at least temporarily to the substrate 14 by means
of the pressure sensitive adhesive 100. This displaces
the spring plate 92 from an initial unstressed position
to a secondary stressed position wherein the spring plate
~'
1~28Ç~2
-18(a)-
applies a positive force pressing the attachment toward
the substrate, as
l~Z~
--19--
depicted by arrows 10~ in FIG. 16. In this manner, the
bonding agent at the attachment/substrate interface is
forced intimately into the interstices of the
structures at the interface with a uniform force
applied across the interface throughout a cure period
thereby achieving a substantially optimum bonding
strength. After curing of the bonding agent, the
mounting fixture 118 may be stripped from the substrate
leaving the attachment in place bonded onto the
substrate. Alternately, if desired, the fixture 118
can be formed in groups as described with respect to
FIGS. 11-13 for inætallation in an automated manner.
If desired, the installation tool 126 or the
installation head 62 may be adapted for use with
various types of bonding agents. For example, as
viewed in FIG. 17 with respect to the tool 126, the
bonding agent 40 at the attachment/substrate interface
may _omprise a hot melt or thermoset adhesive material.
In this case, the installation tool 126 may include a
heating element 110 connected, for example, to the
metal stud 36 for applying heat energy input thereto as
depicted by arrows 112. The stud conducts the input
heat downwardly to the attachment/substrate interface
to activate the hot melt bonding agent prior tc,
installation tool withdrawal.
A~ viewed in FIG. 1~, the amount of the
bonding agent 40 applied to the attachment/substrate
interface may be v~ried to insure permanent mounting
~ixture attachment to the sub~trate ~or some
specialized applications. For example, an excess of
the bondinq agent 40 can be applied to the
attachment/substrate interface to insure radially
outward extrusion of a bead 40' of the bondirlg agent
into an annular space between the attachment footplate
38 and the radially inner diameter surface of the
mounting fixture connector ring 96. When cured, the
bonding agent bead 40' securely bonds the mounting
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i
fixture 118 to the attachmen~ footplate 38 and thereby
maintains the mounting fixture in a position to protect
and shield the attachment footplate. If desired, ~he
mounting fixture may be constructecl from a suitable
material designed to seal the attachment/substrate
interface against undesired outgassing from attachment
components.
Still other alternative bonding agent
compositions can be used, with the installation tool
126 or the head 62 being adapted for facilitated
mounting of the adhesive attachment and activation of
the bonding agent. For example, as viewed in FIGS. 19
and 20, encapsulated beads 114 of the bonding agent may
be applied to the underside surface 130 of the
attachment footplate 38, wherein such bonding agent is
activated for curing by rupturing of the beads for
exposure of the bonding agent to air and/or moisture
within the air. Alternatively, as viewed in FIG. 21,
discrete beads 116 and 117 of different bonding agent
composi~.ions may be applied to the underside of the
footplate 38, wherein intermixing of the two components
initiates a curing process.
The bonding agents shown in FIGS. 19-21 may be
activated by modification of the installation tool 126,
for examplo, to i~sure bead rupture or compo~ent
intermixing inaldent to attachment placement upon a
substrate 14. For example, as vlewed in FIG. 22, the
installat~on tool 126 may include vibratory means such
as an ultrasonic vibratory head 120 for connection to
the attachment 10 as by connection to the threaded stud
36 or other appropriate structure. The attachment
footplate 38 is thus vibrated at an ultrasonic
frequencv as it is move~ by the installation tool. i~,t:o
landed colltact ~pon the substrate, thereby activatinq
the bonding agent on the underslde surface thereo,.
Alternatively, as viewed in FIG. 23, the installation
tool 126 mav be provided with rotational means such as
Z~
-21-
a rotary head 122 secured to the attachment stud 36 or
other structure for rotation of the attachment after
landing upon the substrate. The attachment is rotated
through a sufficient angular displacement to rupture
and/or intermix the bonding agent to initiate
activation of bonding agent curing.
The improved fixture of the present invention
is thus adapted for cost-efficient, high volume
production, preferably as a one-piece plastic molding.
The fixture is designed for rapid temporary securing to
a substrate in combination with quick and easy movement
of a portion of the fixture to a position forced
against the substrate. In some embodiments, means are
provided for maintaining attachment orientation
relative to the substrate, and means can be provided to
facilitate fixture removal from a substrate subsequent
to attachment installation.
A variety of modifications and improvements to
the improved fixture and the adhesive attachment
carried thereby are believed to be apparent to those
skilled in the art. Accordingly, no limitation is
intended by way of description herein, except as set
forth in the appended claims.
