US 3514867 A
Description (OCR text may contain errors)
June 2, 1970 R. PATRICK CLOTHES DRYERS WITH REVERSING DRUM 2 Sheets-Sheet 1 Filed June 21, 1969 INVENTOR.
RUSSELL PATRICK his ATTORNEYS June 2, 1970 R. PATRICK 3,514,867 'cno'mms DRYERS wz'rn REVERSING DRUM Filed June 21, 1969 2 Sheets-Sheet 2 Fig. 2
RUSSEL L PATRICK kw/w his ATTORNE YS United States Patent 3,514,867 CLOTHES DRYERS WITH REVERSING DRUM Russell L. Patrick, Jamestown, N.Y., assignor to Blackstone Corporation, a corporation of New York Filed June 21, 1968, Ser. No. 739,055 Int. Cl. F26b 19/00 US. Cl. 34-45 7 Claims ABSTRACT OF THE DISCLOSURE A drum type clothes dryer is provided to eliminate balling and reduce wrinkling by rotating the drum in one direction with heated air flowing through the drum for a first period of time and then reversing the rotation of the drum and continuing the flow of heated air for a second period of time, preferably at a higher rate of flow.
This invention relates to clothes dryers and particularly to a reversing dryer apparatus. Clothes dryers of the type having a rotating drum in which clothes are placed for drying are well known. Such dryers have a motor for rotating the drum, a source of heat (electric or gas), and a means for moving air over the heat source and through the drum to dry the clothes. Typical of such dryers is that shown in Douglas Pats. 2,861,355 and 3,066,422.
It is Well known that clothes tend to ball during drying, particularly in the presence of sheets and that, as a result, they are wrinkled, hard to handle and require more ironing and finishing than clothes which do not ball. Various attempts have been made to prevent balling by control of speed of rotation of the drying drum and by other means, but without any real success.
I have discovered a clothes dryer which eliminates the problems of balling by accepting the fact that balling will occur under some conditions in almost every dryer and that this can be overcome by reversing the rotation of the dryer drum for a short period of time at a proper point in the drying cycle.
In a preferred embodiment and practice of my invention I provide a housing, a hollow clothes receiving drum mounted in said housing for rotation on its axis, a source of heat, means for supplying a flow of air across the heat source and through said drum, drive means for rotating said drum in opposite directions and control means sensitive to temperature change acting on the drive means whereby the drum is rotated in one direction while the temperature is below a selected level at which the control means is activated for a first period of time and the drum is rotated in the opposite direction when the temperature in the drum rises above the selected level at which the control means is activated for a second period of time. Preferably the drive means is a reversing electric motor. The control means is preferably a pair of thermostats, one controlling the starting windings of the electric motor and the other the running windings of the drive motor.
In the foregoing general description I have set out certain objects, purposes and advantages of my invention. Other objects, purposes and advantages will be apparent from a consideration of the following description and the accompanying drawings in which:
FIG. 1 is a side elevation, partly broken away, showing a clothes dryer embodying my invention;
FIG. 2 is a wiring diagram of the dryer of 'FIG. 1; and
FIG. 3 is a partial section on the line III-III of FIG. 1;
FIG. 4 is a segmental section of a gas dryer of this invention.
Referring to the drawings I have illustrated a housing 3,514,867 Patented June 2, 1970 carrying a cylindrical drum 11 on bearing surfaces 12 which engage surfaces in openings in the ends of drum 11. The drum 11 is provided with a drive belt 13 engaging a pulley 14 on a reversing motor 15. The motor 15 drives a centrifugal fan 16 which carries air from the atmosphere through duct 17, across heat source 18 into the opening at one end of drum 11. The direction of rotation of motor 15 is controlled by a single pole double throw thermostat 19 which is normally closed but opens at some selected temperature (say 130 F.) and closes at a lower temperature (say F.) and which operates a single pole double throw switch 20 which completes the start Winding circuit. A second higher temperature thermostat 21 shuts off the motor 15 and heat source 18 when the exhaust air from drum 11 reaches some preselected temperature (as for example 140 F.) and recloses at some suitable lower temperature (as for example F.). I
The operation of the dryer of my invention is as follows. Clothes are placed in the drum 11 and the drive motor 15 and heat source 18 are energized through a main switch 22 between power line 23 and the dryer control thermostats 19 and 21. Both thermostats are in their normally closed positions (solid line in FIG. 2) and the drive motor rotates drum 11 and fan 16 carries air across the energized heat source 1 8 through the drum 11 and the clothes therein. As the clothes approach dryness or the clothes begin to ball up the drum temperature increases. When the drum temperature reaches a selected point (as 130 F.), the thermostat 19 is activated tripping switch 20 and reversing the starting winding of motor 15. This does not affect the rotation until the motor is stopped by thermostat 21 being activated by the temperature reading a selected point F.) at which time it switches the motor and heat source 011. The heat and motor remain off until the temperature drops sufiiciently to activate thermostat 21 (say 130 F.). During this time the thermostat 19 is still holding the starting winding switch in the reversed direction so that when thermostat 21 closes the motor and fan are reversed. The reversal of motor 15 causes the drum 11 to reverse its rotation, but does not reverse the flow of air by centrifugal fan 16 although the volume of air changes as the direction of rotation changes as is inherent in such a fan. This causes the clothes which have balled to unball and completes the drying and cooling of the cothes in the direction opposite the original rotation and reduces the problem of balling and wrinkling.
A pair of idler wheels 30 and 31 bear against the drive belt 13 on opposite sides to take up the slack and provide tension on the slack side of the belt. The idler wheels 30 and 31 are connected together by spring 33 which provides the necessary tension to take up the belt slack. The idler wheels 30 and 31 are mounted on one end of each of two lever arms 34 and 35 whose other ends are pivoted on the motor base 36.
FIG. 4 illustrates a dryer which is identical with that shown in FIG. 1 except that a gas burner 40 is substituted for heating element 16. All of the corresponding parts bear like numbers with a prime sign.
While I have illustrated and described a presently pre ferred embodiment and practice of my invention in the foregoing specification, it will be understood that this invention may be otherwise embodied within the scope of the following claims.
1. A clothes dryer comprising a housing, a hollow clothes receiving drum mounted for rotating on its axis in said housing and open at each end, a source of heat, means for supplying a flow of air across said source of heat and through said drum, drive means for rotating said drum in opposite directions and control means acting on the drive means and the source of heat stopping the drive means and source of heat whereby the drum is rotated in one direction while the source of heat is operative for a first period of time and then restarting the source of heat and the drive means in reverse direction whereby the drum is rotated in the opposite direction and the source of heat is operative for a second period of time.
2. A clothes dryer as claimed in claim 1 wherein the means for supplying air is driven by the drive means and the control means is a pair of thermostatic switches both normally closed to operate the drive means in one direction with the heat source operative and opening at a preselected temperature in the drum to reverse the drive means while the heat source continues to be operative.
3. A clothes dryer as claimed in claim 1 wherein the means for supplying a flow of air is a centrifugal blower and the drive means rotates the drum and acts on the means for supplying a flow of air through the drum so that when the drum rotation is reversed, the flow of air is continued in the original direction.
4. A clothes dryer as claimed in claim 1 wherein the drive means is a reversing electric motor.
5. A clothes dryer as claimed in claim 1 wherein the source of heat is an electrical heating coil.
6. A clothes dryer as claimed in claim 1 wherein the source of heat is a gas burner.
7. A clothes dryer as claimed in claim 3 wherein the flow of air is increased in the same direction when the blower impeller direction is reversed.
References Cited UNITED STATES PATENTS JOHN J. CAMBY, Primary Examiner US. Cl. X.R. 3452