Door latching apparatus actuated by cleansing agent sensor

• US 3,967,478 A
• Filed: 06/09/1975
• Issued: 07/06/1976
• Est. Priority Date: 06/09/1975
• Status: Expired due to Term

• Current Assignee: Stanley G. Guinn
• Original Assignee: Stanley G. Guinn
• Inventors: Guinn, Stanley G.
• Primary Examiner(s): Gilliam, Paul R.
• Application Number:
  US05/585,323
• Time in Patent Office: 393 Days
• Field of Search: 70/144, 70/277, 70/282, 70/DIG. 46, 4/222, 136/83, 204/195 R, 204/248, 128/2, 128/12, 324/29, 340/279, 292/144, 292/201
• US Class Current: 70/144
• CPC Class Codes: E05B 1/0069 Sanitary doorknobs or handles, e.g. comprising a disinfectant
• CPC Class Codes: G08B 21/245 Reminder of hygiene compliance policies, e.g. of washing hands
• CPC Class Codes: Y10T 70/5385 Spring projected
• CPC Class Codes: Y10T 70/7124 Retracted electrically only

Abstract

An apparatus for unlatching a door to a hygienic area actuated by sensor electrodes in contact with the electrolytic residue of a cleansing agent upon the hand or limb of a person desiring access to the hygienic area.

Claims

1. An apparatus for latching and unlatching a door in a door frame, comprising:

a. an electromagnetic bolt mechanism adapted to latch said door to said door frame when said bolt mechanism, is de-energized and to unlatch said door from said door frame when said bolt mechanism is energized,

b. an electrical energy source for said electromagnetic bolt mechanism,

c. a pair of electrolytically dissimilar electrodes mounted in the vicinity of said door,

d. said electrodes being spaced apart a distance no greater than the length of the portion of a human limb coated with the electrolytic residue of a cleansing agent spanning and in contact with both said electrodes, whereby an electric current may be established between said electrodes and through said electrolytic residue,

e. electrical switch means connected to said electromagnetic bolt mechanism and to said energy source, and,

f. means for actuating said switch means to energize said bolt mechanism, when an electric current is established across said electrodes.

2. The invention according to claim 1 in which said switch means and said actuating means comprises an electrical gate switch in series with said electrical energy source and the electrical coil of said electromagnetic bolt mechanism, a gating lead connecting one of said electrodes to said gating switch, whereby a current crossing said electrodes and through said gating lead will bias said gate switch device into conduction for energizing the electrical coil of said electromagnetic bolt mechanism.

3. The invention according to claim 2 in which said gate switch comprises an SCR, and further comprising a re-set switch device adapted to open the series circuit containing said electrical source, said electrical coil and said SCR, upon actuation.

4. The invention according to claim 3 in which said re-set switch device comprises a pair of switch elements, one on said door and one on said door frame, normally engaging each other when said door is closed within said door frame, and adapted to be separated by the opening of said door, whereby said re-set switch device is actuated when said door is closed and de-actuated when said door is open.

5. The invention according to claim 1 in which said dissimilar electrodes comprise a pair of plates of dissimilar conductive materials mounted on said door.