Subfloor towline conveyor system

Claim 2

A tow cart for a tow line conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon, said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end just clears the driving element; and mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including pivotal linkage means operable to cause driving forces on said tow pin to exert a downward moment on said linkage means to thereby bias said tow pin toward the conveyor chain when said tow pin is disposed in said first position, and operable to cause driving forces on said tow pin to exert an upward moment on said linkage means to thereby bias said tow pin away from the conveyor chain when said tow pin is disposed in a position intermediate said first and second positions.

Claim 3

A tow cart as claimed in claim 1, wherein the path of movement of said free end between said first and second positions lies substantially in a single plane.

Claim 4

A tow cart as claimed in claim 2, wherein said plane is generally vertical.

Claim 5

A tow cart as claimed in claim 1, wherein the path of movement of said free end is generally arcuate.

Claim 6

A tow cart as claimed in claim 4, wherein said path lies generally in a vertical plane.

Claim 7

A tow cart as claimed in claim 5, wherein the longitudinal apogee of said arcuate path is disposed at a level between said first and second positions of said free end.

Claim 8

A tow cart as claimed in claim 6, wherein said axis is disposed closely adjacent to and slightly above the level of said first position of said free end.

Claim 9

A tow cart as claimed in claim 1, wherein the axis of said tow pin lies generally in a longitudinal plane including the path of movement of said drive element, said free end being disposed rearwardly with respect to the opposite end of said tow pin in said first position.

Claim 10

A tow cart as claimed in claim 8, wherein said longitudinal plane extends generally vertically.

Claim 11

A tow cart as claimed in claim 1, further comprising bumper means on said tow cart responsive to engagement with an obstacle to cause said tow pin to move from said first position to said second position.

Claim 12

A tow cart as claimed in claim 10, wherein said mounting means permits movement of said tow pin from said first position to said second position without actuating said bumper means.

Claim 13

A tow cart as claimed in claim 1, further comprising locking means responsive to cams located in the path of movement of said tow cart to positively lock said tow pin in said first position.

Claim 14

A tow cart as claimed in claim 1, wherein said mounting means includes first link means pivotally connected adjacent one end to said body, second link means pivotally connected adjacent one end to the other end of said first link means, and third link means pivotally connected adjacent one end to said body and adjacent the other end to the other end of said second link means, said pivotal connections to said body being spaced from one another in a direction parallel to the direction of movement of the conveyor chain, said tow pin being supported by said second link means.

Claim 15

A tow cart As claimed in claim 1, wherein the movement of said tow pin with respect to said tow cart is solely pivotal.

Claim 16

A tow cart as claimed in claim 1, wherein said mounting means includes sleeve means rotatably supporting said tow pin, and means preventing axial movement between said two pin and said sleeve means.

Claim 17

A tow cart as claimed in claim 1, further comprising stop means affixed to said tow cart, and positive locking means pivotally connected to said tow chart and depending therefrom adjacent the conveyor chain, said locking means being movable between a locking position in which it engages said stop means to prevent upward movement of said tow pin and a nonlocking position in which it clears said stop means upon upward movement of said tow pin.

Claim 18

A tow cart as claimed in claim 1, further comprising a hold back dog on said conveyor chain spaced forwardly from each of said driving elements, each of said hold back dogs including a tow pin engaging surface facing said corresponding driving dog.

Claim 19

A tow cart as claimed in claim 17, wherein said tow pin engaging surface is disposed at a level which will engage said tow pin in said intermediate position.

Claim 20

A tow cart as claimed in claim 1, wherein upward movement of said tow pin is not restricted in said first position thereof.

Claim 21

A tow cart for a towline conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end just clears the driving element; and mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including first link means pivotally connected adjacent one end to said body, second link means pivotally connected adjacent one end to the other end of said first link means, and third link means pivotally connected adjacent one end to said body and adjacent the other end to the other end of said second link means, said pivotal connections to said body being spaced from one another in a direction parallel to the direction of movement of the conveyor chain, said tow pin being supported by said second link means.

Claim 22

A tow cart for a towline conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end just clears the driving element; and mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including first link means pivotally connected adjacent one end to said body, second link means pivotally connected adjacent one end to the other end of said first link means, and third link means pivotally connected adjacent one end to said body and adjacent the other end to the other end of said second link means, said pivotal connections to said body being spaced from one another in a direction parallel to the direction of movement of the conveyor chain, said tow pin being supported by said second link means.

Claim 23

A tow cart as claimed in claim 20, wherein said pivotal connections to said body are disposed on opposite sides of said second link means in a direction parallel to the movement of the conveyor chain.

Claim 24

A tow cart as claimed in claim 20, wherein said first link means is disposed above said third link means.

Claim 25

A tow cart as claimed in claim 20, wherein said pivotal connection between said body and said first link means is disposed rearwardly of said second link means, and wherein said pivotal connection between said third link means and said body is disposed forwardly of said second link means.

Claim 26

A tow cart as claimed in claim 20, wherein said first link is shorter in length than said second link means.

Claim 27

A tow cart as claimed in claim 20, wherein said first means is shorter in length than said third link means.

Claim 28

A tow cart as claimed in claim 20, wherein said third link means is shorter in length than said second link means.

Claim 29

A tow cart as claimed in claim 20, wherein said first link means is shorter in length than said third link means and said third link means is shorter in length than said second link means.

Claim 30

A tow cart as claimed in claim 20, wherein said second link means lies in a vertical plane including the conveyor chain and slightly inclined with respect to the vertical in said plane when said tow pin is in said first position, with the lower end thereof disposed rearwardly of the upper end thereof, said first link means extending generally forwardly and downwardly and said third link means extending generally Horizontally when said tow pin is in said first position.

Claim 31

A tow cart for a tow line conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon, said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end just clears the driving element; and mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including pivotal linkage means so constructed as to cause driving forces of the conveyor chain on said tow pin to exert a downward moment of said linkage means to thereby bias said tow pin toward the conveyor chain when said tow pin is disposed in said first position.

Claim 32

A tow cart for a tow line conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon, said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end just clears the driving element; and mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including pivotal linkage means so constructed as to cause driving forces of the conveyor chain on said tow pin to exert a downward moment of said linkage means to thereby bias said tow pin toward the conveyor chain when said tow pin is disposed in said first position.

Claim 33

A tow cart as claimed in claim 27, further comprising means preventing said bumper means from permitting said tow pin to move away from said second position when the obstacle engaged moves slightly away from the tow cart.

Claim 34

A tow cart as claimed in claim 10, further comprising cam means on said tow cart for moving said tow pin from said first position to said second position in response to engagement with a ramp disposed adjacent the conveyor chain.

Claim 35

A tow cart as claimed in claim 31, wherein movement of said tow pin by said cam means does not cause actuation of said bumper means.

Claim 36

A tow car as claimed in claim 29, wherein said mounting means further provides a substantially rigid connection between said tow pin and said tow cart in the direction of movement thereof.

Claim 37

A tow cart for a tow line conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon, said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end clears the driving element; mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including sleeve means rotatably supporting said tow pin, first link means pivotally connected adjacent one end to said body, second link means pivotally connected adjacent one end to the other end of said first link means, and third link means pivotally connected adjacent one end of said body and adjacent the other end to the other end of said second link means, said pivotal connections to said body being spaced from one another in a direction parallel to the direction of movement of the conveyor chain, said sleeve means being part of said second link means; and means preventing axial movement in both directions between said tow pin and said sleeve means.

Claim 38

A tow cart for a tow line conveyor including a forward moving powered conveyor chain or the like having a plurality of driving elements thereon, said tow cart comprising: a load carrying body; a tow pin having a free end, said tow pin being movable between a first driven position in which said free end thereof is positioned to be drivingly engaged by a driving element on the conveyor chain, and a second nondriven position in which said free end clears the driving element; mounting means for attaching said tow pin to said body for movement between said first and second positions, said mounting means including sleeve means rotatably supporting said tow pin, first link means pivotally connected adjacent one end to said body, second link means pivotally connected adjacent one end to the other end of said first link means, and third link means pivotally connected adjacent one end of said body and adjacent the other end to the other end of said second link means, said pivotal connections to said body being spaced from one another in a direction parallel to the direction of movement of the conveyor chain, said sleeve means being part of said second link means; and means preventing axial movement in both directions between said tow pin and said sleeve means.