Electric heating – Heating devices – With power supply and voltage or current regulation or...
Patent
1989-12-28
1992-06-30
Paschall, Mark H.
Electric heating
Heating devices
With power supply and voltage or current regulation or...
219502, 219518, 219508, 99333, 99329P, H05B 102
Patent
active
051265362
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to electric toasters and associated control means. In particular, the present invention relates to providing apparatus for controling, regulating and/or sensing the extent of toasting.
BACKGROUND OF THE INVENTION
Various food products each require a varying degree of toasting in order to effect a desired "browness". For example, bread, muffins, crumpets and other food products each exhibit a varying degree of inherent untoasted browness, which inherent browness often results in excessive or inadequate toasting of the food product.
Conventional toasters perform adequately when set with respect to white bread but may over-toast brown bread and toasters which perform adequately when set with respect to brown bread may under-toast white bread. Compensation for the above may be effected by adjusting the toaster. This is often not precise and is often otherwise inconvenient or easily forgotton.
Furthermore, few toasters additionally incorporate a "warmup" feature, independent of a toasting function. Also, should the toaster be activated, without any food product therein, often hazardous toaster operation occurs, as a result of excessive heat.
U.S. Pat. No. 2,436,575 discloses a toaster which uses light emanating from a light source and reflected from toast, and measured either continuously or discontinuously, to produce a controlling current, which current operates a series of relays. When the current achieves a predetermined magnitude, the activated relays terminate the toasting operation. The specification also discloses a momentary delay operation to allow the photoelectric cell time to attain equilibrium when first measuring untoasted bread. U.S. Pat. No. 2,436,575 does not disclose a toaster wherein compensation for browness is effected dependent on the food product to be toasted.
U.S. Pat. No. 3,956,978 discloses a switching mechanism for a toaster to terminate supply of electricity to the toasting elements. This specification also discloses an alternative circuit which measures toast browness via light reflected from a separate light source in the toaster and also discloses a differential amplifier which triggers the termination of toasting when a desired browness is reached. However, the disclosed arrangement does not establish a signal which is needed to compensate for different bread types.
U.S. Pat. No. 4,363,957 discloses apparatus adapted to cook or char varied foodstuffs wherein the degree of charring is varied for each foodstuff. The control circuit described appears to generally disclose a circuit which stores a voltage representative of the maximum voltage provided by the optical sensor, that is minimum resistance of the sensor or maximum reflectively of the article, and uses this as a comparison datum in a comparator to compare changes or decreases in voltage as the article chars, to turn the power off at a certain changed level. U.S. Pat. No. 4,363,957 does not disclose the general concept of using a peak holding circuit to establish a reference representative of the maximum reflected light from the untoasted bread, measuring subsequent reflected light for the bread as it is being browned, comparing these results with a preset voltage representative of desired browning and terminating the toasting cycle when reaching the preset voltage in a toaster. The disclosure relies on a light source other than the toaster elements. The disclosure further does not teach a toaster having a timed warmup system, independent of the light sensor technique and also does not disclose a failsafe mechanism.
U.S. Pat. No. 4,426,572 relates to an improvement to U.S. Pat. No. 4,363,957. This disclosure deals with apparatus which more accurately measures light reflected from foodstuff being toasted. U.S. Pat. No. 4,433,232 relates to a further improvement to U.S. Pat. No. 4,363,957 and U.S. Pat. No. 4,426,572. This disclosure deals with the problem of accurately measuring the browness of foodstuff being browned, by avoiding the problem of light reflecting from t
REFERENCES:
patent: 3956978 (1976-05-01), Borley
patent: 4083054 (1978-04-01), Moraw et al.
patent: 4245148 (1981-01-01), Gisske et al.
patent: 4345145 (1982-08-01), Norwood
patent: 4363957 (1982-12-01), Tachikawa et al.
patent: 4433232 (1984-02-01), Tachikawa et al.
patent: 4510376 (1985-04-01), Schneider
patent: 4755656 (1988-07-01), Charlesworth et al.
Black & Decker Inc.
Hoofnagle J. Bruce
Paschall Mark H.
LandOfFree
Control arrangement for food heating device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control arrangement for food heating device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control arrangement for food heating device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1865396