Tow cart safety mechanism

Claim 2

In a tow cart driven by conveyor drive means, a driving and release arrangement comprising: drive pin means carried by said cart and having one end portion adapted to be engaged by said conveyor drive means; means supporting said drive pin means for axial movement placing said one end portion into and out of engagement with said conveyor drive means; a stored force means and an overcenter toggle mechanism associated therewith, said overcenter toggle mechanism having a cocked position and an alternate released position, said stored force means and said toggle mechanism restraining forward movement of said one end portion relative to said cart in said cocked position, and releasing said forward restraint to permit said one end portion to move freely away from said drive means and substantially simultaneously exerting a force to move said one end portion axially out of engagement with said drive means upon release of said stored force means; and means for moving said stored force means and toggle mechanism from said cocked position to said released position in response to a predetermined degree of obstruction to the forward movement of said cart.

Claim 3

In an arrangement according to claim 1 wherein: said pin supporting means includes means supporting said pin means for forward pivotal movement of said one end portion of said pin means about a pivotal connection remote from said one end portion.

Claim 4

In an arrangement according to claim 2 including: return spring means urging said one portion of said pin means rearwardly about said pivotal connection.

Claim 5

In an arrangement according to claim 1 wherein: said stored force means comprises a compression spring located forwardly of a portion of said pin means adjacent said one end portion; and said toggle mechanism is located between said compression spring and said portion of said pin means adjacent said one end portion.

Claim 6

In an arrangement according to claim 4 wherein: said overcenter toggle mechanism comprises a double toggle linkage having said cocked position on one side of dead center, and said release position on the other side of dead center.

Claim 7

In an arrangement according to claim 1 wherein: said tow cart includes a floor line bumper displaceable rearwardly and connected to operate said means for moving said stored force means and toggle mechanism from said cocked to said released position.

Claim 8

In an arrangement according to claim 6 wherein: said tow cart includes a personnel cage displaceable rearwardly; and linkage means connecting said personnel cage to said means for moving said stored force means and toggle mechanism from said cocked to said released position so that said predetermined degree of obstruction of either said bumper or said personnel cage will operate said last-named means.

Claim 9

In a floor supported tow cart driven by in-floor conveyor drive means, a driving and release arrangement comprising: drive pin means carried by said cart and having a bottom end portion adapted to be engaged by said conveyor drive means; means supporting said drive pin means for both axial movement placing said bottom end portion into and out of engagement with said conveyor drive means and for pivotal forward movement of said bottom end away from said conveyor drive means; pin position control means, comprising a compression spring and an overcenter toggle mechanism associated therewith, holding said pin means in its rearward position in a cocked position of said pin position control means, and releasing said pin means for said forward pivotal movement to permit said bottom end portion to move freely away from said drive means and substantially simultaneously exerting a force to move said pin means upwardly upon triggering of said pin position control means from a cocked position toward a released position; floor bumper means, and separate personnel cage means, carried by said cart and displaceable rearwardly relative to said cart in response to a predetermined degree of obstruction to forward movement of said bumper means and said cage means; and means linking both said bumper means and said cage means to said pin position control means to effect triggering thereof in response to said predetermined degree of obstruction of either.

Claim 10

In a floor supported tow cart driven by in-floor conveyor drive means, a driving and release arrangement comprising: drive pin means carried by said cart and having a bottom end portion adapted to be engaged by said conveyor drive means; means supporting said drive pin means for both axial movement placing said bottom end portion into and out of engagement with said conveyor drive means and for pivotal forward movement of said bottom end away from said conveyor drive means; pin position control means, comprising a compression spring and an overcenter toggle mechanism associated therewith, holding said pin means in its rearward position in a cocked position of said pin position control means, and releasing said pin means for said forward pivotal movement to permit said bottom end portion to move freely away from said drive means and substantially simultaneously exerting a force to move said pin means upwardly upon triggering of said pin position control means from a cocked position toward a released position; floor bumper means, and separate personnel cage means, carried by said cart and displaceable rearwardly relative to said cart in response to a predetermined degree of obstruction to forward movement of said bumper means and said cage means; and means linking both said bumper means and said cage means to said pin position control means to effect triggering thereof in response to said predetermined degree of obstruction of either.

Claim 11

In a floor supported tow cart driven by in-floor conveyor drive means, a driving and release arrangement comprising: drive pin means carried by said cart and having a bottom end portion adapted to be engaged by said conveyor drive means; means supporting said drive pin means for both axial movement placing said bottom end portion into and out of engagement with said conveyor drive means and for pivotal forward movement of said bottom end away from said conveyor drive means; pin position control means holding said pin means in its rearward position in a cocked position of said pin position control means, and releasing said pin means for said forward pivotal movement to permit said bottom end portion to move freely away from said drive means and substantially simultaneously exerting a force to move said pin means upwardly upon triggering of said pin position control means from a cocked position toward a released position; floor bumper means, and separate personnel cage means, carried by said cart and displaceable rearwardly relative to said cart in response to a predetermined degree of obstruction to forward movement of said bumper means and said cage means; and means linking both said bumper means and said cage means to said pin position control means to effect triggering thereof in response to said predetermined degree of obstruction of either, said linking means includes a parallelogram linkage, one element thereof comprising a portion of a reset lever, and an adjacent element comprising a lifter rod carrying lift finger means adapted to engage said pin means for effecting lifting thereof.

Claim 12

In a floor supported tow cart driven by in-floor conveyor drive means, a driving and release arrangement comprising: drive pin means carried by said cart and having a bottom end portion adapted to be engaged by said conveyor drive means; means supporting said drive pin means for both axial movement placing said bottom end portion into and out of engagement with said conveyor drive means and for pivotal forward movement of said bottom end away from said conveyor drive means; pin position control means holding said pin means in its rearward position in a cocked position of said pin position control means, and releasing said pin means for said forward pivotal movement to permit said bottom end portion to move freely away from said drive means and substantially simultaneously exerting a force to move said pin means upwardly upon triggering of said pin position control means from a cocked position toward a released position; floor bumper means, and separate personnel cage means, carried by said cart and displaceable rearwardly relative to said cart in response to a predetermined degree of obstruction to forward movement of said bumper means and said cage means; and means linking both said bumper means and said cage means to said pin position control means to effect triggering thereof in response to said predetermined degree of obstruction of either, said linking means includes a parallelogram linkage, one element thereof comprising a portion of a reset lever, and an adjacent element comprising a lifter rod carrying lift finger means adapted to engage said pin means for effecting lifting thereof.

Claim 13

In an arrangement according to claim 9 wherein: said lift finger means is yieldably connected to said lifter rod.