Adhesive supply unit

An adhesive supply unit is provided with a tank having fins which maximize the heat exchange area of the tank for melting hot melt adhesive. Each fin features a cut out which is of such a size and shape as to allow the placement of a block of unmelted adhesive in the tank while at the same time maximizing the surface area of the fins to improve heat transfer. An electronics control unit is located adjacent one end of the tank and has a fan located in the top of the cabinet over the control unit which fan blows in ambient air from the outside downwardly over the electronic controls contributing to an efficient cooling of the electronics. A coupler is used to align the pump and air motor located on the bottom of the device consists of a sleeve which supports the shaft and an outer bore which fits into corresponding bores in both the air motor and pump thereby aligning all three items and providing a sealing function as well.

BACKGROUND OF THE INVENTION 
Hot melt adhesive supply units are in general well known. As the need for 
application becomes more sophisticated, increasing amounts of control have 
been provided for such supply units. Such needs necessitate the provision 
for sophisticated electronics in the unit. The environments for such 
electronics is quite hostile however as the amount of heat required to 
melt the hot melt is substantial and thus provision needs to be made for 
protecting the delicate electronics in the environment. 
For efficient operation, it is also desirable to be able to melt blocks of 
hot melt as quickly as possible. It is generally considered well known to 
increase the surface area of the tank by providing fins therein and it is 
therefore an object to this invention to provide a device which is capable 
of quickly melting the raw hot melt. 
It is also an object to this invention to provide a device which may be 
easily and inexpensively manufactured and which is capable of rapid yet 
accurate assembly in sealing. 
SUMMARY OF THE INVENTION 
In the instant invention, the hot melt adhesive tank is provided with fins 
which extend across and which extend at least in part substantially the 
height and width of the tank. The fins have a recess in the center thereof 
of approximately the width and depth of a block of hot melt so as to allow 
placement of full uncut blocks in the tank while at the same time 
maximizing the surface area for heat transfer. 
The cooling apparatus for the instant invention is provided by a fan 
located in the top of the cabinet located directly over the electronics of 
the control unit. The electronics are mounted adjacent one end of the tank 
and as such are subject to a substantial amount of heat. By blowing 
ambient cool air downwardly over the electronics, increased cooling 
efficiency is provided even through contrary to the normal direction of 
flow from convection cooling. The intake for the ambient air faces 
forwardly away from the heat source of the tank. 
A cylindrical bearing member is provided between the air motor and the pump 
which are located beneath the cabinet body and serve to align the pump and 
motor relative to one another as well as locate and seal the shaft that 
runs between the two units. Due to the construction, alignment is assured 
and assembly is greatly facilitated. 
These and other objects and advantages of the invention will appear more 
fully from the following description made in conjunction with the 
accompanying drawings wherein like reference characters refer to the same 
or similar parts throughout the several views.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows the hot melt adhesive supply unit 10. As seen more 
particularly in FIG. 2, an air intake unit 12 is formed of a U shaped 
piece of perforated metal 14. A foam filter element 16 located in the top 
18 of cabinet 20. Air is drawn through filter element 16 by fan 22 and 
blown downwardly over the electronics control package 24. Electronics 
control package 24 for controlling the temperature of adhesive in the tank 
is located on a dividing wall 26 immediately adjacent tank 28 and is thus 
in a position to deletriously be affected by heat unless properly cooled. 
The air continues downwardly through holes 30 in the bottom 32 of cabinet 
20. 
FIG. 3 shows in detail tank 28. Each fin 34 extends substantially the width 
and height of the tank to maximize surface area. An indentation is formed 
in the middle where downwardly sloping edges 36 meet at horizontal shelf 
38 which is of such a width as to allow an unmelted block of hot melt 
adhesive (shown in phantom as 40) to be placed. Heating element 42 is 
placed in the bottom of the tank to cause the melting. 
FIG. 2 also shows located beneath the bottom 32 of cabinet 20 an air motor 
44 which is connected to pump 48 using bearing housing 46. Turning to FIG. 
4, bearing housing 46 is generally cylindrical in shape and fits into an 
aperture 50 in pump 48 and aperture 52 in air motor 44. A shaft 54 runs 
through the middle of the adapter and is supported and aligned thereby. A 
flange 56 seats against the end of pump 48 and is held in place by a 
collar 58 which is in turn clamped in place by the end of air motor 44. A 
bearing member 60 slideably locates shaft 54 in the middle and a wiping 
seal 62 is located at the end thereof. Seal 62 is held in place by a snap 
ring 64. A seal 66 acts to form a seal between bearing housing 46 and pump 
48. This construction assures constant alignment between the two members 
while at the same time being easy to manufacture and assemble as well. 
It is contemplated that various changes and modifications may be made to 
the adhesive supply unit without departing from the spirit and scope of 
the invention as defined by the following claims.