Mother/daughter industrial cart coupling arrangement

A coupling system for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, the coupling system comprising:

• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• and
• a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• wherein the locking apparatus is configured to automatically engage and lock the daughter cart to the mother cart as the daughter cart is moved in a generally perpendicular direction to the primary direction of transport with the third coupling rail slidingly disposed between the first and second coupling rails.

A coupling system for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, the coupling system comprising:

• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• and
• a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• wherein the locking apparatus is remotely dis-engagable, to thereby release the third rail and allow the daughter cart to be moved out of engagement from the mother cart.

A coupling system for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, the coupling system comprising:

• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• the daughter cart includes a caster locking arrangement for locking at least one caster against swiveling motion;
• the coupling system is configured such that the at least one caster wheel is automatically unlocked to allow swiveling motion of the at least one caster as the third coupling rail engages the first and second coupling rails to couple the daughter cart to the mother cart;
• and
• the coupling system is further configured such that the at least one caster wheel is automatically locked to preclude swiveling motion of the at least one caster as the third coupling rail disengages from the first and second coupling rails when the daughter cart is decoupled from the mother cart.

A coupling system for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, the coupling system comprising:

• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• the mother cart, daughter cart and coupling system are configured to allow the daughter cart to be coupled to the mother cart from either side of the mother cart;
• and
• one or more of the coupling system rails are configured such that they form a common connection for coupling and conveying two or more daughter carts.

A mother cart for conveying at least one daughter cart in a transport direction, wherein each conveyable daughter cart includes a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface, and the mother cart comprises:

• a mother cart frame defining a primary transport direction of the mother cart frame and supported by wheels for rolling engagement with the underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the at least one daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails;
• at least one of the mother and daughter carts frames are moveable in a direction generally perpendicular to the primary transport direction to slideably position the third coupling rail in the channel without either the wheels of the mother cart or the casters of the daughter cart passing through the channel;
• and
• the at least one daughter cart being coupled to and moving with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails.

A mother cart for conveying at least one daughter cart in a transport direction, wherein each conveyable daughter cart includes a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface, and the mother cart comprises:

• a mother cart frame defining a primary transport direction of the mother cart frame and supported by wheels for rolling engagement with the underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the at least one daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the at least one daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• the coupling system further includes a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart.

A mother cart for conveying at least one daughter cart in a transport direction, wherein each conveyable daughter cart includes a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface, and the mother cart comprises:

• a mother cart frame defining a primary transport direction of the mother cart frame and supported by wheels for rolling engagement with the underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the at least one daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the at least one daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• one or more of the coupling system rails are configured such that they form a common connection for coupling and conveying two or more daughter carts.

A mother cart for conveying at least one daughter cart in a transport direction, wherein each conveyable daughter cart includes a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface, and the mother cart comprises:

• a mother cart frame defining a primary transport direction of the mother cart frame and supported by wheels for rolling engagement with the underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the at least one daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the at least one daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• the at least one daughter cart includes a caster locking arrangement for locking at least one caster against swiveling motion;
• the coupling system is configured such that the at least one caster wheel is automatically unlocked to allow swiveling motion of the at least one caster as the third coupling rail engages the first and second coupling rails to couple the at least one daughter cart to the mother cart;
• and
• the coupling system is further configured such that the at least one caster wheel is automatically locked to preclude swiveling motion of the at least one caster as the third coupling rail disengages from the first and second coupling rails when the at least one daughter cart is decoupled from the mother cart.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails;
• at least one of the mother and daughter carts frames are moveable in a direction generally perpendicular to the primary transport direction to slideably position the third coupling rail in the channel without either the wheels of the mother cart or the casters of the daughter cart passing through the channel;
• and
• the daughter cart being coupled to and moving moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• the coupling system further includes a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• and
• the locking apparatus is configured to automatically engage and lock the daughter cart to the mother cart as the daughter cart is moved in a generally perpendicular direction to the primary direction of transport with the third coupling rail slidingly disposed between the first and second coupling rails.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• the coupling system further includes a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• and
• the locking apparatus is remotely dis-engagable, to thereby release the third rail and allow the daughter cart to be moved out of engagement from the mother cart.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• one or more of the coupling system rails are configured such that they form a common connection for coupling and conveying two or more daughter carts to the mother cart with the coupling system.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• the at least one daughter cart includes a caster locking arrangement for locking at least one caster against swiveling motion;
• and
• the coupling system is configured such that the at least one caster wheel is automatically unlocked to allow swiveling motion of the at least one caster as the third coupling rail engages the first and second coupling rails to couple the at least one daughter cart to the mother cart;
• and
• the coupling system is further configured such that the at least one caster wheel is automatically locked to preclude swiveling motion of the at least one caster as the third coupling rail disengages from the first and second coupling rails when the at least one daughter cart is decoupled from the mother cart.

A daughter cart adapted to be conveyable in a transport direction by a mother cart having a mother cart frame defining a primary transport direction of the mother frame and supported by wheels for rolling engagement with the underlying surface, wherein the daughter cart includes:

• a daughter cart frame supported by casters adapted for rolling engagement with an underlying surface;
• and
• one or more coupling rails of a coupling system having first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• wherein:
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• the daughter cart is an over-cart having a frame that defines a generally inverted U-shape, with first and second substantially vertically extending side sections joined at upper ends thereof by a substantially longitudinally extending load bearing section thereof, to thereby form a space beneath over-cart frame adapted for straddling an object disposed beneath the over-cart, with the over-cart frame being further configured for attachment to the mother cart frame using the coupling system.

A mother/daughter cart arrangement, comprising:

• a mother cart having a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface;
• at least one daughter cart having a daughter cart frame supported by casters above the underlying surface;
• and
• a coupling system for joining at the least one daughter cart to the mother cart for conveying the at least one daughter cart along the primary transport direction;
• wherein:
• the coupling system including first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails;
• at least one of the mother and daughter carts frames are moveable in a direction generally perpendicular to the primary transport direction to slideably position the third coupling rail in the channel without either the wheels of the mother cart or the casters of the daughter cart passing through the channel;
• and
• the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails.

A mother/daughter cart arrangement, comprising:

• a mother cart having a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface;
• at least one daughter cart having a daughter cart frame supported by casters above the underlying surface;
• a coupling system for joining at the least one daughter cart to the mother cart for conveying the at least one daughter cart along the primary transport direction;
• and
• a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• wherein:
• the coupling system including first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• the locking apparatus is configured to automatically engage and lock the daughter cart to the mother cart as the daughter cart is moved in a generally perpendicular direction to the primary direction of transport with the third coupling rail slidingly disposed between the first and second coupling rails.

A mother/daughter cart arrangement, comprising:

• a mother cart having a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface;
• at least one daughter cart having a daughter cart frame supported by casters above the underlying surface;
• a coupling system for joining at the least one daughter cart to the mother cart for conveying the at least one daughter cart along the primary transport direction;
• and
• a locking apparatus for locking the coupling rails against further motion with respect to one another at a desired transport position of the daughter cart with respect to the mother cart;
• wherein:
• the coupling system including first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• the locking apparatus is remotely dis-engagable, to thereby release the third rail and allow the daughter cart to be moved out of engagement from the mother cart.

A mother/daughter cart arrangement, comprising:

• a mother cart having a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface;
• at least one daughter cart having a daughter cart frame supported by casters above the underlying surface;
• and
• a coupling system for joining at the least one daughter cart to the mother cart for conveying the at least one daughter cart along the primary transport direction;
• wherein:
• the coupling system including first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• and
• one or more of the coupling system rails are configured such that they form a common rail connection for coupling and conveying two or more daughter carts with the mother cart using the common rail connection of the coupling system.

A method for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, and the method comprises joining the at least one daughter cart to the mother cart using a coupling system that includes:

• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• the first and second coupling rails forming a channel between the first and second coupling rails;
• at least one of the mother and daughter carts frames are moveable in a direction generally perpendicular to the primary transport direction to slideably position the third coupling rail in the channel without either the wheels of the mother cart or the casters of the daughter cart passing through the channel;
• and
• the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails.

A method for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, and the method comprises:

• joining the at least one daughter cart to the mother cart using a coupling system that includes:
• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• and
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• configuring one or more of the coupling system rails to form a common rail connection for coupling and conveying two or more daughter carts with the mother cart;
• and
• using the common rail connection of the coupling system.

A method for joining at least one daughter cart to a mother cart, wherein the mother cart has a mother cart frame defining a primary transport direction and supported by wheels for transport above an underlying surface, and the daughter cart has a daughter cart frame supported by casters above the underlying surface, and the method comprises:

• joining the at least one daughter cart to the mother cart using a coupling system that includes:
• first and second coupling rails attached to one of the mother and daughter cart frames, and a third coupling rail attached to the other of the mother and daughter cart frames;
• the first, second and third coupling rails extending in a parallel manner to one another in a direction generally perpendicular to the primary transport direction and parallel the underlying surface, when the coupling rails are operatively engaged for transporting the daughter cart with the mother cart;
• and
• the first and second coupling rails forming a channel between the first and second coupling rails for sliding receipt therein of the third coupling rail, in such a manner that the daughter cart is coupled to and moves with the mother cart as the mother cart is moved in the primary transport direction while the third coupling rail is positioned in the channel between the first and second coupling rails;
• wherein the daughter cart includes a lockable swiveling caster wheel that is selectively lockable to preclude swiveling motion of the caster wheel, and the method further includes automatically unlocking the caster wheel with the coupling system as the daughter cart engages the mother cart, to thereby allow swiveling motion of the swiveling caster wheel when the daughter cart is coupled to the mother cart, and automatically locking the swiveling caster wheel against pivoting motion, with the coupling system, as the daughter cart disengages from the mother cart.