Jam detection and safety device for jamming machinery

In a baler having a ram and a shear bar, the baler being prone to jamming from material being process by the baler, an apparatus comprising:

• at least one strain gage mounted on the shear bar of the baler, wherein the baler experiences increased strain when the baler becomes jammed;
• a controller electrically connected to the strain gage and being operable to deactivate the ram if the strain of the shear bar exceeds a predetermined strain value corresponding to a jamming condition;
• an electrical panel that connects high voltage line power to the baler;
• and
• a control panel connected to the electrical panel and operable to supply low-voltage control power to the baler;
• wherein the electrical panel comprises a first trapped key switch for receiving a removable, first key, the first trapped key switch being operable to move between an on position to allow the line power to be connected to the baler and an off position to prevent the connection of line power to the baler, wherein the first trapped key switch is operatively connected to the controller and cannot be manually moved from the off position to the on position unless the controller sends an electrical signal to the first key switch;
• wherein the control panel comprises a second trapped key switch for receiving a removable, second key, the second trapped key switch being operable to move between an on position to allow the control power to be turned on and an off position to prevent the control power from being turned on, wherein the second trapped key switch is operatively connected to the controller and cannot be manually moved from the off position to the on position unless the controller sends an electrical signal to the second key switch.