Reduction of initial film winding resistance in camera film magazines

Claim 2

In a film magazine including means for defining a film supply compartment having an inner surface, a film passageway leading from said compartment, and an elongate strip of film having a leading end and a web thickness said film being spirally wound into a film supply roll which is housed within said compartment with said leading end extending from the outermost convolution of said roll into said passageway, said roll being of a size in which said outermost convolution normally engages said supply compartment inner surface, when said roll is in said supply compartment, and said film having an inherent plasticity, a clockspringing tendency, and an initial resiliency, said inherent plasticity, clockspringing tendency, and initial resiliency of said film decreasing as the film ages in the compartment, the improvement wherein: a section of said strip of film which comprises at least a portion of said outermost of said roll is so substantially transversely corrugated as to have a predetermined initial effective thickness which is greater than said web thickness and is at least initially disposed to contact both said inner surface of said supply compartment and the convolution of said supply roll which is adjacent to said section so that, as said filmstrip ages in said magazine and said initial resiliency decreases, said corrugations relax and said initial effective thickness decreases to reduce the frictional contact pressure between the outermost film convolution and the supply compartment inner surface.

Claim 3

A film magazine according to claim 1 in which said corrugated section of said film has an initial effective thickness equal to at least twice the web thickness of said strip.

Claim 4

A film magazine according to claim 1 in which said corrugated section of said strip of film completely encircles said film supply roll and extends therefrom into said passageway.

Claim 5

A film magazine according to claim 1 further including means defining an internal film take-up compartment and a rotatable winding core housed within said take-up compartment, and wherein said elongate strip of film includes an uncorrugated leading end section attached to said winding core.

Claim 6

In an elongate strip of film having a web thickness and adapted to be at least partly wound into a film supply roll for insertion into a film supply compartment of a film magazine, said compartment having an inner surface and said roll being of a size in which the outermost convolution normally engages said supply compartment inner surface, when said roll is in said supply compartment, and said film having an inherent plasticity, a clockspringing tendency, and an initial resiliency said inherent plasticity, clockspringing tendency and initial resiliency of said film decreasing as the film ages in the compartment, the improvement wherein: a section of said strip of film which comprises at least a portion of said outermost convolution is so substantially transversely corrugated as to have a predetermined initial effective thickness which is greater tHan said web thickness and is at least initially disposed to contact both said inner surface of said supply compartment and the convolution of said supply roll which is adjacent to said section, so that, as said filmstrip ages in said compartment and said initial resiliency decreases, said corrugations relax and said initial effective thickness decreases to reduce the frictional contact pressure between the outermost film convolution and the supply compartment inner surface.

Claim 7

In an elongate strip of film having a web thickness and adapted to be at least partly wound into a film supply roll for insertion into a film supply compartment of a film magazine, said compartment having an inner surface and said roll being of a size in which the outermost convolution normally engages said supply compartment inner surface, when said roll is in said supply compartment, and said film having an inherent plasticity, a clockspringing tendency, and an initial resiliency said inherent plasticity, clockspringing tendency and initial resiliency of said film decreasing as the film ages in the compartment, the improvement wherein: a section of said strip of film which comprises at least a portion of said outermost convolution is so substantially transversely corrugated as to have a predetermined initial effective thickness which is greater tHan said web thickness and is at least initially disposed to contact both said inner surface of said supply compartment and the convolution of said supply roll which is adjacent to said section, so that, as said filmstrip ages in said compartment and said initial resiliency decreases, said corrugations relax and said initial effective thickness decreases to reduce the frictional contact pressure between the outermost film convolution and the supply compartment inner surface.

Claim 8

In a container for web material comprising: a wall defining a generally cylindrical supply chamber having an inner surface; a passageway extending through said wall from said supply chamber; and a web spirally wound into a roll within said supply chamber, said roll having at least one inner convolution and an adjacent outer convolution and being of a size in which said outer convolution normally engages said supply chamber inner surface, when said roll is in said supply chamber, and said web having a thickness, an inherent plasticity, a clockspringing tendency, and an initial resiliency, said inherent plasticity, clockspringing tendency, and initial resiliency of said web decreasing as the web ages in said chamber, the improvement wherein: a section of said outer convolution is so substantially transversely corrugated that it has a predetermined initial effective thickness which is greater than said web thickness and is at least initially disposed to contact both said inner surface of said supply chamber and said inner convolution, so that, as said web ages in said supply chamber and said initial resiliency decreases, said corrugations relax so as to decrease said initial effective thickness and thereby reduce the frictional contact pressure between the outer web convolution and said inner surface of said supply compartment.

Claim 9

In a container for web material comprising: a wall defining a generally cylindrical supply chamber having an inner surface; a passageway extending through said wall from said supply chamber; and a web spirally wound into a roll within said supply chamber, said roll having at least one inner convolution and an adjacent outer convolution and being of a size in which said outer convolution normally engages said supply chamber inner surface, when said roll is in said supply chamber, and said web having a thickness, an inherent plasticity, a clockspringing tendency, and an initial resiliency, said inherent plasticity, clockspringing tendency, and initial resiliency of said web decreasing as the web ages in said chamber, the improvement wherein: a section of said outer convolution is so substantially transversely corrugated that it has a predetermined initial effective thickness which is greater than said web thickness and is at least initially disposed to contact both said inner surface of said supply chamber and said inner convolution, so that, as said web ages in said supply chamber and said initial resiliency decreases, said corrugations relax so as to decrease said initial effective thickness and thereby reduce the frictional contact pressure between the outer web convolution and said inner surface of said supply compartment.

Claim 10

In an elongate strip of film for being wound into a roll and loaded into a film supply compartment of a film magazine, said compartment having an inner surface and said roll being of a size in which said outermost convolution of said roll normally engages said supply compartment inner surface, when said roll is in said supply compartment, and said strip of film having a web thickness, an inherent plasticity a clockspringing tendency, and an initial resiliency, said inherent plasticity, clockspring tendency, and initial resiliency of said film decreasing as said film ages in said compartment, the improvement wherein: a section of said strip of film is so substantially transversely corrugated as to have a predetermined initial effective thickness which is greater than said web thickness, said corrugations defining a first corrugated segment operable to form said outermost convolution of said roll and a second corrugated segment operable to form the adjacent inner convolution thereof, the corrugations of said first segment and said second segment intersecting both lateral edges of said film the crests of each corrugated segment of said inner and outer convolutions transversely contacting the other of said corrugated segments along a distance which is less than the width of the strip of film, so that the corrugations of said second segment and the corrugations of said first segment are in unmeshed relationship with respect to the corrugations of said second segment, when said film is wound into the film supply roll, whereby, as said film strip ages in said compartment and said initial resiliency decreases, said corrugations relax and said initial effective thickness decreases to reduce the frictional contact pressure between said outermost film convolution and said inner surface of said supply compartment.

Claim 11

In an elongate strip of film for being wound into a roll and loaded into a film supply compartment of a film magazine, said compartment having an inner surface and said roll being of a size in which said outermost convolution of said roll normally engages said supply compartment inner surface, when said roll is in said supply compartment, and said strip of film having a web thickness, an inherent plasticity a clockspringing tendency, and an initial resiliency, said inherent plasticity, clockspring tendency, and initial resiliency of said film decreasing as said film ages in said compartment, the improvement wherein: a section of said strip of film is so substantially transversely corrugated as to have a predetermined initial effective thickness which is greater than said web thickness, said corrugations defining a first corrugated segment operable to form said outermost convolution of said roll and a second corrugated segment operable to form the adjacent inner convolution thereof, the corrugations of said first segment and said second segment intersecting both lateral edges of said film the crests of each corrugated segment of said inner and outer convolutions transversely contacting the other of said corrugated segments along a distance which is less than the width of the strip of film, so that the corrugations of said second segment and the corrugations of said first segment are in unmeshed relationship with respect to the corrugations of said second segment, when said film is wound into the film supply roll, whereby, as said film strip ages in said compartment and said initial resiliency decreases, said corrugations relax and said initial effective thickness decreases to reduce the frictional contact pressure between said outermost film convolution and said inner surface of said supply compartment.