Capacitive press control actuation system
AssigneeISB Ltd.
InventorJames Kirton
Life of this patent
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Abstract
In a preferred embodiment, a capacitive switch system including two capacitive switches which must be activated nearly simultaneously to operate a piece of equipment. When one switch is touched, a timing function is activated. If a predetermined length of time lapses before the other switch is touched, the other switch will be locked out. Both switches must then be released before the activation procedure is re-initiated. The components providing timed and anti-tie-down features, are integral to the circuitry of the switches and these as well as output relays are compactly housed in the switch housings to prevent tampering and circumvention of the safety features. The sensitivity of the switches is such that they cannot be activated by liquids.
Claims20
A switch system having first and second switches for activating punch presses and the like, each said switch comprising:
- (a) a housing;
- (b) electronic circuitry disposed within said housing, said electronic circuitry including timing and anti-tie-down functions;
- and
- (c) a capacitive sensor coupled to said electronic circuitry, and spaced apart from a portion of said housing which is touched by a user of said system to actuate said switch, each said capacitive sensor comprising:
- (i) coplanar outer and inner members;
- (ii) said outer member having a single U-shape form with substantially parallel legs connected by a segment;
- and
- (iii) said inner member having a straight form lying along the central axis of said outer member and extending into said said outer member approximately two-thirds of the length of said legs.
A switch system having first and second switches for activating punch presses and the like, said first and second switches each comprising:
- (a) a housing;
- (b) capacitive sensing means disposed in said housing to detect the proximity of a portion of an operator of said switch system and to provide an output voltage proximity signal at a level indicating said proximity;
- and
- (c) timed and anti-tie-down circuit means;
- and wherein, in operation:
- (d) said timed and anti-tie-down circuit means in one of said first and second switches receives said proximity signal, provides a timed signal to the other of said first and second switches indicating the presence of said proximity signal for a selected interval of time, receives a timed signal from said other of said first and second switches if timed and anti-tie-down circuit means in said other of said first and second switches has received a proximity signal from capacitive sensing means in said other of said first and second switches for said selected interval of time, and closes said one of said first and second switches only if said proximity signal in said other of said first and second switches has been received for a selected period of time less than said selected interval of time.
Dependencies are inferred from the claim text.