ELECTRIC SAFETY CONTROL MECHANISM

• US 3,861,016 A
• Filed: 11/19/1973
• Issued: 01/21/1975
• Est. Priority Date: 11/19/1973
• Status: Expired due to Term

• Current Assignee: Emhart Inc. (Stanley Black & Decker, Inc.)
• Original Assignee: Frederick S. Sillars, Herbert Johnson
• Inventors: Johnson, Herbert, Sillars, Frederick S.
• Primary Examiner(s): Eager, Thomas H.
• Application Number:
  US05/417,417
• Time in Patent Office: 428 Days
• Field of Search: 29/23B,23R 83/544,546
• US Class Current: 29/708
• CPC Class Codes: F16P 3/02 Screens or other safety members moving in synchronism with members which move to and fro
• CPC Class Codes: F16P 3/12 with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine F16P3/08 takes precedence
• CPC Class Codes: Y10T 29/53035 Responsive to operative [e.g., safety device, etc.]
• CPC Class Codes: Y10T 29/53174 Means to fasten electrical component to wiring board, base, or substrate
• CPC Class Codes: Y10T 83/872 With guard means

Abstract

A guard is movably mounted in a machine adjacent to shiftable operating mechanism potentially capable of injuring an attendant as by clamping his hand when it is inadvertently interposed between the operating mechanism and some other portion of the machine. A safety circuit associated with the guard includes a switch means responsive to guard contact with an obstruction, and/or to manual displacement of the guard in any of several directions whereby the operating mechanism is at once deactivated and injury avoided. One advantageous embodiment of the invention, for instance, is in an automatic component inserting machine wherein the head and/or the work support is programmed for relative traverse.

Claims

1. In a machine having elements relatively movable along convergent paths, and power means for driving at least one of the elements, a safety means comprising a guard mounted for movement with said one of the elements and displaceable in two or more directions relative to said one element, and a circuit for controlling actuation of the drive means, the circuit including a switch means responsive to displacement of the guard in any one of said directions for immediately deenergizing the power drive means.

2. A machine as in claim 1 wherein the guard is mounted for yielding displacement on said one element from a neutral or inoperative position on the guard, and spring means is adapted to urge return of the guard to said neutral position to restore operation of the machine.

3. A machine as in claim 1 wherein the guard is formed as a box-like fence adjacent to operating instrumentalities and is at least partly transparent to permit visual operation of the instrumentalities of the machine.

4. A machine as in claim 1 wherein the safety guard is mounted for pivotal movement about an axis, and is yieldable in either of opposite directions parallel to said axis.

5. A machine as in claim 1 wherein the switch means is mounted on said one element and includes a pair of independently operable, spaced switches, and switch actuating means associated with the guard and adapted to partake of its relative displacement is operable to actuate either of the switches to deenergize the machine drive means.

6. Safety mechanism for a machine having elements movable With relative approach to each other in a manner such that there is risk of an operator or article being caught or being endangered therebetween, the safety mechanism comprising a guard pivotally mounted on one of the movable elements for movement about a horizontal axis, means permitting the guard lateral yieldable movement in either of two directions along the axis from a neutral inoperative position, power means for driving said one or more of the elements, a safety control circuit connected to the power means and including switch means actuatable for deenergizing said power means, and mechanism responsive to deflection of the guard about said axis or along that axis for causing the switch means to deenergize said circuit and thereby render the power means inoperative.

7. Safety mechanism as in claim 6 wherein spring means is yieldingly operable to urge the deenergizing mechanism to resume an angular position wherein the control circuit remains energized.

8. Safety mechanism as in claim 6 wherein the switch means includes a pair of switches connected in parallel, and the mechanism for causing the switch means to deenergize the control circuit comprises a switch actuator connected to the guard and having a cam portion formed to cooperate with the pair of switches.

9. Safety mechanism as in claim 8 wherein said switch actuator is an extension of the guard having a recessed portion for accommodating the actuating arm of one of the pair of switches when the machine is in normal operating condition.

10. The combination with an electronic component mounting machine comprising a frame, means movably mounted on the frame for supporting a wiring board which is to receive leads of the components in different predetermined positions, a component processing head movably mounted on one side of the board supporting means, lead clinching mechanism operable on the other side of the board supporting means, and power means for driving at least two of said head, clinching mechanism, and board supporting means with relative movement of approach toward one another, of a safety mechanism including a guard yieldingly associated with at least one of the head, clinching mechanism and board supporting means, and a control circuit responsive to displacement of the guard from an inoperative position to stop said relative movement of approach by deenergizing the power means, the control circuit including switch means actuatable by relative heightwise, lateral, or pivotal movement of the guard with respect to the head, clinching mechanism, or board supporting mechanism with which the guard is associated.