US2550118A - Clothes drier - Google Patents

Description

April 24, 1951 w. L. KAuFFMAN. u 2,550'118 CLOTHES DRIER w .Filed July 51, 1944 3 Sheets-Sheet 1 z INVENTOR.

April 24, 1951 w. L. KAUFFMAN, u

CLOTHES DRIER 5 Sheets-Sheet 2 Fiiled July 51, 1944 fi/J INVENTOR. want: w

ATTORNEY.

pr'l 24, 1951 w. L. KAUFFMAN,

CLOTHES DRIER 3 Sheets-Sheet 3 Filed July 31, 1944 INVENTOR.

ATTORNEY.

theV drum casing. z

Patented Apr. 24,v 1 951 CLOTHES DRIER Walter L. Kaufiman, II, Eric, Pa., assignor to Lovell Manufacturing Company, Eric, Pa., a corporation of Pennsylvania Application July 31, 1944, Serial No. 547,380

7 Claims. 1

The present invention relates to clothes driers of the type in which the clothes are tumbled in a rotatable drum and dried by heat and air supplied to the drum.

The object of my invention is to provide an improved construction and arrangement in driers of this type having, among other advantages, an improved arrangement for handling lint and a simplified control. i

In the accompanying drawings, Fig. 1 is a front perspective of the drier; Fig. 2 a rear view with the back panel of the cabinet removed; Fg. 3 is a, perspective of the cabinet base; Fig. 4 is a detail of the belt tightener; Fig. 5 is a frag-V I mentary view of the lint filter; Fig. 6 is a control diagram; Fig. 6a is a perspective of the push button and temperature control; Fig. 7 is a section on line 'i-T Aof Fig. 2; Fig. 8 is a section on line 8-8 of Fig. '7; Fig. 9 is a top plan view of the cabinet base and exhaust duet; Fig. 10 is a section throughthe trough leading to the exhaust fan inlet; Fig; ll is a detail of the adjustment for `Referring to the drawings, there is shown a drier'having a cabinet supportedA on abase 2. Tothe back section 3 of the 'base is fixed a box section column 4 carrying a bearing bracket 5 for a shaft 6 fiXed to the back end 1 of a drum 8. The front end, 9 of the drum has a central fianged opening IQ having a running clearance Withia circular flange ll on the front section of the cabinet. Except while clothes are `being loaded or unloaded, the opening defined by the fiange Il is normally closed by a door 12 having a cylindrical projection [3 extending into the drum. When the door is closed, the fiow of air f into and out of the drum is confinedto the outer periphery Id which is of perforated metal. On the inner periphery of the drum are axial ribs, |5 lwhich provide a better grip for tumbling the clothes during rotation of thedrum. v

`'The drum is enclosed by a closely fitting casing having front and back ends |5, l'l respectively,

supported by stiffening members IB (Figs. 7, 8)

adjacent the front cabinet section and by the column 4. The ends |6, I'l are provided with inwardly extending peripheral flanges IQ around which is wrapped a sheet 20 formingthe center section Vof the drum housing. The ends of the Sheet are secured to brackets 2! (Fig. 11) by bolts 22 which permit a peripheral shifting of the sheet. As shown in Figs. 2 and 11, the ends of the sheet 20 are spaced apart, part of the space being filled by a reflector 23 for a heating element 24. Along one edge of the reflector is a slot 25 through which air fiows to the drum. The air fiowing to the slot 25, as shown in Fig. ,7, is taken' increases from the front to the back of the w cabinet where it terminates in a circular flange 28 connected by a fiexible tube 29 to the intake 30 of a centrifugal fan 5| mounted on the rear section 3 of the base. The fan discharges parallel to the rear section of the base through an opening 32 (Figs. 3, 9) into a duct 33 between a removable plate 34 and a side section of the base. At the front of the duet is a filter screen 35 slidable to one side to permit access to the duet to remove lint and a fixed filter screen 36 forming a common wall between the -duct 33 and a by-pass passage 31 having its inlet 38 between a defiector M and the inner end of the filter 35. The air discharged from the fan is guided along the duet by a deflector 39 on the rear corner of the duet and fiows past a thermostat bulb 40 supported by braekets 40a and past the deflector 4! to the filters 35, 36 at the front corner of the duct. The filters are arranged to set up a swirling motion of the air at the front cover tending to deposit lint along the inner surfaees of the filters. The defiector M extends into the duet beyond the by-pass inlet 38 in the direction of air flow so that under normal operation any air fiowing into the inlet 38 must turn a sharp corner which keeps lint out of the inlet until the'filter screens are filled to capacity. If the filter screens are filled to capacity, theair, with any entrained lint, fiows out through the by-pass inlet 38 which is of sufiicient area to provide for nearly normal air. fiow through the fan. The presence of lint at the frontof the by-pass passage 3? indicates to the operator that the filter screens need cleaning. Because the air flow is maintained, there is no fire hazard if the filter screens are not cleaned.

The action of the defiector 4| in keeping lint out of the by-pass passage during normal operation is partly due to inertiaseparation resulting from the fact that the air fiowing to the inlet 38 must turn a sharp corner and partly to an injector action produced by the air stream fiowing past the defiector. So long Vas the filter screens are not elogged, these effects are sufficient to keep lint out of the by-pass passage.

The fan and drum are driven by a motor 132 mounted on the top of the discharge duct 33 (the plate 3d being removed to permit access to the motor bolts) and having a double pulley 43, one part of which drives the blower through a belt M and the other part of which drives the drum through a double belt reduction consisting of a drum pulley 45 and an idler pull'ey Mi. The idler pulley is carried on a stub shaft projecting Vfrom a bracket 41'! pivotally and slidably carried in an arm 48 fixed to the column 4. The belt tension is maintained by a spring 49.

The motor is Controlled by a push button switch D having contacts 5| connected in one side 51a of a 220 volt power line to which is connected (through conductors 5lb, 5Ic) the motor, a pilot light 52, (through conductor Sid) and one side of a heating element Z (through conductor 5 le). The switch also has contacts 53 connected in the other side 53a of the 220 volt power line and through a temperature limiting thermostat 54 (and switch 58) to the other side of the heating element 24. The temperature limiting thermostat 54 is carried by the drum casing adjacent the heating element and prevents excessive temperatures in the drum in case the normal air fiow through the drum is not maintained or is interrupted. Normal air fiow might be interrupted by clogging of the discharge duct, by failure of the belt drive to the fan, or by opening the door 42.

The most common cause of operation of the temperature limiting thermostat is the opening of the door, which permits the air to fiow directly to the drum and out through the trough 21, bypassing the normal circulation of air and permitting heated air to accumulate adjacent the heating element. Under normal conditions with the door closed, the air enters the drum solely through the slot adjacent the heating element and distributes the heat throughout the drum. The thermostat 54 is of the automatic resetting type so the circuit to the heating element is re-established as soon as the temperature drops to a safe value.

At the start of the drier operation the push button switch is closed, establishing the circuits to the motor, pilot light, and heating element and causing the r-otation of the drum to tumble the clothes and the operation of the blower to crculate heated air through the drum.

During the initial part of the drying operation, the cabinet 'and the parts enclosed are heated and the temperature of the air exhausted through the duct 33 rises at a rather rapid rate. After this initial rise, which, of course, would not be present if the drier were warm, the temperature of the exhaust air is held down by the evaporation of moisture from the clothes. The evaporation of moisture proceeds at a substantially constant rate until the clothes approach drynes's, when the rate of evaporation decreases and the temperature of the exhaust air gradually increases. Upon reaching' a temperature determined by an adjustment 55, a bellows 56 associated with the thermostat 40 expands and moves the push button switch to the open position in which it is held by an over-center spring 57. .By the adjustment which varies the position of the actuator 50a of the push button switch relative to the bellows 55, the drier can be shut down when the exhaust temperature corresponds to the desired moisture content of the clothes. The adjustment may be of common construction such as a screw thread actuated by turning the push button. It is therefore possible to have the clothes completely dried or dried to a degree suitable for ironing. Because the temperature of the exhaust air is relied upon for controlling the drier, it is important that the air circulation through the drier be maintained throughout its operation. This is attained by the by-pass iduct 31 which has an unrestricted inlet .38 of sufficient sie to maintain the necessary air flow even though the filter screens are clogged.

The efficiency and safety of the drier is increased by the drum casing |6, l'l, 20 which confines and directs the air fiow through the drum. Room temperature air drawn into the cabinet through openings 28 is preheated by the drum `casing before reaching the intake slot 25. The air fiowing through the intake slot fiows past the tumbling clothes and out through the trough 21. Because of the close fit of the drum within the casing, air currents are set up which sweep lint into the trough and keep the inner surface of the drum casing clean. The thermostat bulb 40, be ing located between the fan exhaust 32 and the by-pass inlet 38, is kept clean by the rapidly moving air so lint does not accumulate on the bulb and insulate it so as to interfere with its operation. Even after the Velocity of the air is reduced by the clogging of the filter screens it is sufficient to keep the thermostat bulb clean. The thermostat shuts down the drier before the temperature increases to a point at which the clothes might be iniured. Since the higher temperature prevails when the clothes are dry (or nearly dry) damage to the clothes is prevented.

While the fastest drying is obtained with the full heat, there are some fabrics, such as wool, which cannot stand the moderate temperatures (l35-145 F.) present with full heat. For these fabrics, part of the heating element is open circuited by a switch 53 normally closed by a spring 69 and openedV by an arm 6| on the push button shaft 62 when the push button is turned to set the adjustment 55 to the low temperature (1l0-1l5 F.) suitable for Woolens and rayons.

. For all except the lowest temperature adjustment the switch 58 is closed. The drier operates in the same manner as before, but with lower temperature, the temperature gradually rising at the start, levelling off due toevaporation, and rising at the end of d'rying to effect automatic shut down.

In manufacture, the operative parts of the drier are, assembled on the base, the drum 8 and drum casing 5-24 being mounted on the column z 4, the blower 3! being mounted on the rear section 3 of the base, and Vthe driving motor 42 being mounted on the top wall of the exhaust duct at one side of the base. The exhaust air thermostat M is connected to the control wiring (by 10-- cating its bellows 56 with respect to the push button switch) and mounted on the plate 34 which is positioned in the side of the exhaust duct. After assembling the rem'aining parts the front section of the cabinet, the front, top, and side walls, is then fastened to the base and the cabinet assembly completed by attaching the back wall of the cabinet.

The pilot light 52 and the push button switch 55 are mounted on plates in the upper front wall of the cabinet.

For service, the pilot light 52 and push button switch 50 are disconn'ected and the back wall and then the front section of the cabinet is removed, exposing all of the operative parts of the drier for service Operations.

What I claim as new is:

1. In a Clothes drier, a Casing, a Clothes receiving drum therein rotatable to tumble the Clothes, a fan for exhausting air from the casing, a discharge duct for the fan, a filter for the duct including a part extending back toward the fan -and along a Wall of the duct, and a by-pass passage having a common Wall with said part and p having an inlet on the fan side of said part.

2. In a Clothes drier, a Clothes receiving drum rotatable to tumble the Clothes, a Casing surrounding the drum, a heater radiating heat through an opening in the casing to the upper periphery of the drum, an air inlet to the casing adjacent the heater, an air outlet in the lower part of the casing, an opening'at one end of the drum and casing for loading and unloading Clothes, a closu're' for said opening whereby the air lfiow through the drum is normally confined Vbetween said inlet and outlet, a fan having its intake connected to said outlet for exhausting assne cause fiow of air into said casing, and means forming an outlet for air from said casing in- Cluding a duct having a 'lint arresting screen, and another duct at an angle to said first named duct connected to said first duct at a place reached by the air before it reaches said screen.

6. In a Clothes drier, a casing, a Clothes receiving drum therein rotatable to tumble the Clothes, f fan means for discharging air from the casing,

a duct for the air stream discharged from the Casing by the fan means, a filter screen for the duct intercepting the' discharged air stream, a

' passage by-passing the filter having its inlet effecair at a ratesuch that the Clothes* temperature 3. In a Clothes drier, a casing, a Clothes receiving drum therein rotatable to tumble the Clothes, an air exhaust duct from the casing, a filter for the duct discharg'e'including a part extending back toward the intake end and along a Wall ofv the duct, and an effectively unobstructed bypass passage havingv a common wall with said part and having an inlet on the intake side ofV said part.

4. In a Clothes drier, a Casing, a Clothes receiving'drum therein rotatable to tumble the Clothes,

a heater radiating to the drum, a discharge duct i for. air and lint from the casing, a filter for the duct, an eifectively unobstructed by-pass from the duct for air and lint in excess of the capacity of the filter, and a thermostat in the duct in front of the by-pass passagevfor Cutting off the heater at a predetermined air temperature.

5. A Clothes drier comprising a stationary casing, a rotatable. Clothes drying support in said casing,'heating means in said casing, means to tively unobstructed and arranged 'with respect to the direction of air fiow so air entering the passage must turn a Corner'whereby lint is kept from the passage.

7 In a Clothes drier, a casing, a Clothes receiving drum therein rotatable to tumble the Clothes, fan means for discharging air from the casing, a duct for the air stream discharged by the fan means, a filter screen intercepting the discharged air stream, a passage by-passing the filter having an eif'ectively unobstructed inlet, and means defiecting the discharged air stream beyond the inlet as regards the direction of air fiow for keeping lint from the passage until the filter is clogged.

WALTER L. KAUFFMAN, II.

REFEREN CES CITED The following references are of record in the Name Date 1,075,382 Roost Oct. 14, 1913 1,136,645 Binder Apr. 20, 1915 1,195,983 lFarmer Aug. 29, 1916 1,267,748 Cutter May 28, 1918 1,327,609 Bartholomew Jan. 13, 1920 1,338,696 Power May 4, 1920 l,398,490 Kendrick Nov. 29, 1921 l,567,710 Carroll Dec. 29, 1925 1,667,316 Hartman et al Apr. 24, 1928 1,707,547 Adams Apr. 2, 1929 1,762,594 Seifert June 10, 1930 1,786,191 Carroll Dec. 23, 1930 2,050,625 Orr Aug. 11, 1936 2,113,770 Richardson Apr. 12, 1938 2,293,432 Friedman Aug. 18, 1942 2,314,748 White Mar. 23, 1943 2,334,025 O'Neill Nov. 9, 1943 2,385,223 Moore Sept. 18, 1945 2,406,494 lFerris Aug. 27, 1946

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