Electrically heated tool for use in installation of anchoring devices employing hot melt adhesive

An electrically heated tool for appyling an anchoring device having a forwardly protruding nose carrying a hot melt adhesive and a rear recess surrounded by a circular rim has a housing having a head portion and a handle. The head portion has a planar front wall provided with a front recess dimensioned to receive the anchoring device. An electric heater in the head portion has a platen, dimensioned to extend into the rear recess of the anchoring device, protruding into the front recess. The dimensions of the front recess and platen are such that the nose of an anchoring device received in the front recess with the platen extending into the rear recess of the device and in contact with the rear of the nose thereof protrudes slightly forwardly beyond the plane of the front wall so that the nose of the device can be firmly pressed against a surface to obtain secure bonding of the device after the heater has been energized to melt the adhesive. The head portion and the front recess therein have a maximum width dimension less than the diameter of the circular rim of the anchoring device whereby portions of the rim extend beyond the sides of the head portion to allow the user to easily and safely grip the anchoring device for placement onto the platen in the front recess.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an improved tool for melting hot melt adhesive on 
a fastening device as a preliminary step to bonding the fastening device 
to a mounting surface. 
2. Description of the Prior Art 
It is known to employ hot melt adhesives to bond anchoring devices to walls 
and other like mounting surfaces. Special tools are required to heat the 
anchoring devices and thereby melt the adhesives. 
U.S. Pat. No. 3,719,792 discloses one such tool where the anchoring device 
is received against the face of a relatively larger forwardly protruding 
heating element. In situations where a plurality of anchoring devices are 
being heated in rapid succession, the areas of the heating element which 
extend beyond the anchoring devices are exposed and thus may be contacted 
by a user's fingers. 
U.S. Pat. No. 4,167,259 discloses another prior are tool which is used in 
conjunction with a metal anchoring device. The anchoring device is 
specially configured and dimensioned to complete a magnetic flux circuit 
between the legs of a U-shaped induction core, thereby generating the heat 
required to melt the adhesive. This type of arrangement requires rather 
precise positioning of the anchoring device on the tool, and precludes the 
use of non-metallic anchoring devices, e.g., those molded of plastic. 
One object of the present invention is to provide of a tool which is 
specially adapted to conveniently and safely accept an anchoring device 
for heating. 
A companion objective of the present invention is to provide a tool which 
can be employed with both metallic and non-metallic anchoring devices. 
SUMMARY OF THE INVENTION 
The tool of the present invention is designed for use in applying an 
anchoring device having a forwardly protruding nose carrying hot melt 
adhesive and a rear recess surrounded by a circular rim. The fastening 
device may be metallic or non-metallic. The tool has a housing with both a 
head portion and a handle portion. The head portion has a front wall with 
a front recess, and oppositely facing side walls extending rearwardly from 
the front wall. A heater is contained in the head portion. The heater has 
a platen protruding through the front wall into the front recess. The 
front recess is appropriately configured and dimensioned to removably 
receive a fastening device on the platen, with the platen protruding into 
the rear recess of the thus received anchoring device and into contact 
with the nose thereof. The heater is adapted to heat the platen and the 
nose of the anchoring device in contact therewith to melt the adhesive 
preparatory to pressing the nose of the anchoring device against a support 
surface. The platen is totally enclosed by the anchoring device received 
thereon. 
Advantageously, the width of the tool's head portion between the side walls 
is less than the diameter of the circular rim on the anchoring device, 
thus allowing portions of the rim to protrude laterally beyond the side 
walls. These laterally protruding rim portions allow the anchoring device 
to be held between the fingers of the user and provide a means of easily 
and safely mounting the anchoring device on the heated platen. 
To further enhance safety, the platen is located rearwardly of the plane of 
the front wall of the head portion. Preferably, this rearward location is 
at a distance which is slightly less than the thickness of the nose of the 
anchoring device. Thus, when the anchoring device is mounted on the 
platen, it protrudes slightly beyond the plane of the front wall to 
faciliate application to the mounting surface.

DESCRIPTION OF PREFERRED EMBODIMENT 
With reference to the drawings, the tool of the present invention is 
designed for use with an anchoring device generally indicated at 10. The 
anchoring device has a forwardly protruding nose 12 carrying hot melt 
adhesive 14, and a rear recess 16 surrounded by a circular rim 18. 
The tool 20 of the present invention has a head portion 20a and a handle 
portion 20b. The head portion includes a front wall 22 with oppositely 
facing side walls 24 extending rearwardly therefrom, and with a front 
recess 26 in the front wall. A heater 28 is contained in the head portion 
20a. The heater includes a platen 30 which protrudes through the front 
wall into the front recess 26. The front recess 26 is appropriately 
configured and dimensioned to receive the anchoring device 10 on the 
platen 30, with the platen protruding into the rear recess 16 of the thus 
received anchoring device and into contact with the underside of the nose 
12. The platen 30 is thus totally enclosed by the anchoring device. The 
heater 28 is of the electrical resistance type and is adapted to be 
connected via wire 32 and plug 34 to a conventional electrical outlet (not 
shown). An indicator light 36 is included in the circuit and is visible 
through a window 38 in the housing. Light 36 provides a means of visually 
indicating when the heater is energized. 
When energized, the heater raises the temperature of the platen 30 and the 
nose 12 of an anchoring device in contact therewith to melt the adhesive 
coating 14 preparatory to pressing the nose of the fastening device 
against a support surface. This results in the anchoring device becoming 
bonded to the support surface, as shown for example in FIG. 5. 
As can best be seen in FIG. 3, the maximum width dimension "W" of the head 
portion 20a between the side walls 24 is less than the diameter "D" of the 
circular rim 18 on the anchoring device 10. Thus, when the anchoring 
device is mounted on the platen 30, portions of the rim 18 protrude 
laterally beyond the side walls 24, such laterally protruding portions 
being indicated in FIG. 3 at 18'. These laterally protruding portions can 
be gripped between a user's fingers, thereby providing a convenient and 
safe means of handling the anchoring device without exposure to the heated 
platen 30. 
In order to further enhance safety, the platen 30 is preferably recessed 
rearwarly of the plane "P" of the front wall 22 by a distance d.sub.1. 
Distance d.sub.1 is less than the thickness of the nose portion 12. Thus, 
when the anchoring device is mounted on the platen, the nose portion 
protrudes forwardly beyond the plane P by a slight distance d.sub.2. 
Typically, d.sub.1 will be 0.015", the thickness of the nose 12 will be 
0.030", thus making d.sub.2 also approximately 0.015". 
By locating the platen 30 slightly behind the plane P of the front wall 22, 
there is less likelihood of it being inadvertently contacted by the user. 
The slight forward protrusion of the nose 12 beyond the plane P enables 
the nose to be firmly pressed against a mounting surface to obtain secure 
bonding, with the remainder of the front wall 22 serving as a guide 
surface which resists cocking of the tool and thereby further enhances 
secure bonding. 
As can be best seen in FIG. 4, when the anchoring device is mounted on the 
platen 30, the circular flange 18 is spaced forwardly from the base of the 
recess 26. This insures that there is intimate contact between the platen 
and the rear surface of the nose 12, thereby enhancing rapid and efficient 
heating. 
Preferably, the side walls 24 are provided with vent openings indicated 
typically at 40. This allows ambient air to circulate freely through the 
head portion 20a. 
As indicated in FIG. 5, once the anchoring device 10 is securely bonded to 
a mounting surface, it serves as a base for removably supporting hooks or 
other like elements, as indicated for example by the broken lines at 42. 
Various changes and modifications can be made to the embodiment herein 
chosen for purposes of disclosure without departing from the scope of the 
coverage provided by the claims appended hereto. Examples of such changes 
and modifications might include changing the configuration of the platen 
30 to accommodate differently configured anchoring devices, elimination of 
the indicator light 36, heating the platen 30 by means other than an 
electrical resistance heater, etc.