Confined air food heating apparatus

A housing for heating and rotating foodstuffs has a rotary foodstuff container through which heated air may pass during the heating of the foodstuffs. A door is provided so that the container may be removed axially from the housing. Suspension means for the container are also removable through the door opening. The door is designed to relatively seal the housing when closed.

This invention relates to a device for cooking foodstuffs, by tumbling of 
such foodstuffs in heated air. The invention is particularly suitable for 
but is not limited to cooking potato chips. 
Prior designs for such equipment include Canadian Pat. No. 887,585 to Vogt. 
Vogt shows a housing with a rotary foodstuff tumbler in a bell with an 
impeller over the bell to circulate heated gases through the foodstuffs. 
Such design has had unsatisfactory mechanical performance and has been 
difficult to clean. 
Many of the problems with Vogt were solved by the design shown in Canadian 
Pat. No. 1,045,926 to Winkler et al which disclosed a housing having a 
rotary foodstuff tumbler and a laterally displaced air heating and 
circulating device. The latter arrangement solved the mechanical and the 
cleaning problems of Vogt device. However, the design of Winkler involved 
a rotating partial cover for the access opening in the housing and a 
support for the foodstuffs container which allowed the air to freely move 
into and out of the housing about the partial cover. The result was that 
when the Winkler device was used many times a day, in a small area, the 
cooking odours were sometimes unduly strong. 
Accordingly, this invention provides a housing wherein a rotatable 
foodstuffs tumbler is laterally disposed from an air heating and 
circulating unit. However, the design for support of the tumbler allows 
the tumbler and its support to be completely within the housing which is 
thus provided with a door to substantially close the opening. Such 
substantial closure is by no means air tight but will greatly reduce the 
odours emitted relative to the Winkler device. 
Although the inventive housing is designed to be more nearly air tight than 
prior devices it is necessary with such housing and with the inventive 
design (under the regulations of some jurisdictions) to provide a vent 
operable on the buildup of a predetermined amount of pressure inside the 
housing. This vent however may be releasably biased closed, to open on 
such excess pressure. However the presence of such vent does not detract 
from the advantages of the invention in providing a substantially closed 
housing under normal conditions. 
In accord with a preferred embodiment of the invention, there is provided a 
food tumbling frame with means for inserting and removing the foodstuffs. 
A support is provided on the rearward wall of the housing for rotatably 
supporting the rearward end of said frame. The frame is so supported in 
alignment with the door and the door opening in the housing. A detachable 
support is provided for rotatable supporting the forward end of the frame. 
This support and frame are arranged to be located inside the housing when 
the door is closed. The detachable support is so arranged relative to the 
frame, that the foodstuffs may be withdrawn from or added to the frame 
with the frame and outer support in place. On the other hand, the outer 
support and the frame are designed and arranged so that they may be 
withdrawn from the housing for cleaning. Means are provided, preferably 
combined with the rear frame support for rotating the frame in situ. In 
the housing, and laterally disposed from the locus of the rotating frame, 
are provided means for heating and circulating in the housing, the air 
which heats the foodstuffs.

In the drawings, a rectangular housing 10 is shown having a forwardly 
opening door 12 on the right side of its forward wall. The forwardly 
opening door is bordered with any suitable sealing material 14 such as 
silicone based gasket type material about the door. The closure means 16 
for the door, shown only schematically herein, is designed so that such 
gasketing 14 effectively seals the periphery of the door when the door is 
closed. A wall 18 partially defines an area 20 in the housing inset behind 
the front wall of the housing and laterally disposed from the area of the 
housing aligned with the door. In this area the air heating and 
circulating means are located comprising a centrifugal fan schematically 
shown at 22, an outwardly spiraling wall 24 thereabout defining an air 
path and heating elements 26 in the path. A wall 28 separating the heating 
area from that foodstuff cooking area in the housing aligned with the 
door, provides an inlet 30 to the centre of the fan and is spaced from the 
bottom wall of the housing at 32 to allow the travel of air heated and 
driven by the fan 22 to enter the foodstuff cooking chamber along the 
bottom wall 34 of the housing. 
On the side of the housing 10 remote from the foodstuff heating chamber are 
schematically indicated the controls for the heating, fan and motor. 
Dealing now with the foodstuff cooking frame and the mounting and drive 
therefor, it is desired to describe the foodstuff cooking frame first. 
The frame 36 is preferably rectilinear being square in its forward to 
rearward cross section. Forward wall 38 mounts a stub shaft 40 projecting 
forwardly, while rearward wall 42 mounts a stub shaft 44 keyed (here 
square) for cooperation with a driving means. The top wall of the frame 
and the side wall down to just below the level of the stub shafts 40 and 
44 are provided with an apertured or mesh construction designed to retain 
the foodstuffs while allowing air circulation therethrough. The bottom 
frame members 46 and 48 are designed to slidably mount a drawer 50 which 
slides into the frame through the front thereof where the forward wall is 
cut off just below stub shaft 40 to provide, with the forward members of 
the frame, the drawer opening. The drawer is formed with side and bottom 
walls with apertures or mesh of similar construction to that of the frame, 
for the same purpose and the drawer 50 is designed so that, when in place, 
it forms, with the frame 36, a container in which the foodstuffs may be 
retained while tumbled by rotation of the frame. 
For convenience in withdrawing the drawer, a small loop 52 is fastened on 
its front wall, to which may be attached the tool 54 when the drawer is to 
be inserted or withdrawn from the frame with the latter in situ. 
It will be noted that any shape of frame 36 and drawer 50, with design for 
air circulation therethrough, may be used, it only being necessary that 
the drawer, be on one side only of the pivot point (and open towards the 
rotary axis). 
It is also within the scope of the broader, although not the preferred, 
aspects of the invention to construct a frame without a drawer but with 
another opening for food withdrawal and insertion, since means will be 
described to allow removal of the entire frame. However the drawer and 
frame construction shown is preferred for convenience. 
The frame 36, as shown, cooperates with rotating and mounting means in the 
housing as now described. The rear wall of the housing mounts rotary means 
56 which in use provides a rotating socket 58 to receive and key to the 
stub shaft 44. At the forward side of the housing a loop 60 on the top and 
at the centre of the housing opening mounts a hanger 62 which when 
installed hangs into the opening to mount a socket forming means 64 to 
receive and rotatably mount the forward stub shaft 40 and thereby the 
forward end of frame 36. The hanger 62, in place thus mounts the forward 
end of the frame, its rearward portion supported and driven by the drive 
means socket 58. 
The hanger 62 stops clear of the drawer 50 (FIG. 3) so that the drawer may 
be removed and inserted clear of the hanger, when the drawer is at the 
bottom of the frame. 
Frame 36 and hanger 62 are designed so that in use, and as shown in FIG. 3, 
they are inside the closed door 12 (FIG. 3). 
Other forward mounting means than the hanger may be used, but it must allow 
removal of the frame from the housing for cleaning and when used with a 
frame having a drawer, must allow removal of the drawer without 
interference. (It must also, of course allow rotation of the frame during 
the cooking operation). 
Other rotary drive couplings may, of course, be used. 
In use, the frame is mounted on its rear mounting means and hanger with the 
drawer locus at the bottom, foodstuffs, say potato chips for cooking are 
located in the drawer 50 which is slid into the frame. The door 12 is 
closed, substantially closing off the inner part of the housing. The 
spring loaded vent 59 on the top of the casing will open if an excess of 
pressure develops inside the housing). 
With the foodstuffs, drawer and frame in place, the drive is caused to 
rotate the frame and tumble the foodstuffs and the fan and heater are 
turned on to cook to food. When the food is cooked, the heater and fan are 
stopped and door is opened, the frame 36 will be manually or automatically 
stopped with the drawer 50 at the bottom. The drawer may then be withdrawn 
to remove the foodstuffs. A new batch of foodstuffs may be placed in the 
drawer to respect the operation. 
When it is desired to clean the equipment, the door 12 is opened, and 
hanger 62 and the frame 36 removed from the housing, rendering cleaning 
simple.