CA1307694C

CA1307694C - Film cassette

Info

Publication number: CA1307694C
Application number: CA000593066A
Authority: CA
Inventors: Patricia D. Fairman
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1988-03-25
Filing date: 1989-03-08
Publication date: 1992-09-22
Anticipated expiration: 2009-09-22
Also published as: DE68912800D1; AU3162389A; CN1037040A; KR890015061A; HK143894A; EP0334325A3; DE68912800T2; EP0334325A2; MY103989A; BR8901361A; MX163369B; JPH01306844A; KR920000605B1; AU600405B2; US4846418A; CN1015211B; EP0334325B1

Abstract

Abstract Film Cassette In a 35mm film cassette (1), the leading end (45) of a film roll (37) coiled about a film spool (5) is located within the cassette shell (3).
The film spool (5) is comprised of two pieces (77, 79) constructed to telescopically receive one another. Each spool piece (77, 79) includes a radially extending flange (51, 53) normally disposed adjacent one of the opposite sides (61, 63) of the film roll (37). When the film spool (5) is initially rotated in a film unwinding direction (U), a rotation-responsive cam device (83, 85) coupling the two spool pieces (77, 79) automatically moves one spool piece axially toward the other piece to cause the respective flanges (51, 53) to clamp the film roll (37) at its opposite sides (61, 63). As a result, the leading end (45) of the film roll (37) will be rotated past a stripper-guide (93) which strips the leading end (45) from between the flanges (51, 53) and guides it through a light-trapped opening (25) in the cassette shell (3). Thus rotation of the film spool (5) in the unwinding direction (U) will advance the leading end (45) to the outside of the film cassette (1).

Description

"' 1 3076q4 FILM CASSETTE
The ~nvention rel~tes generally to the field of photography, and particulArly to a film cassette containing a film roll. More specifically, the invention relates to a film cassette wherein a leading end of the film roll can easily be advanced from within the film cassette to the outside of the cassette.
In the standard 35mm film manufacturers' cassette, such as manufactured by Eastman Kodak Co.
and Fu~ i Photo Film Co., Ltd., the filmstrip is wound on a flanged spool which is rotatably supported within a cylindrical shell. A leading end section of the filmstrip approximately 2 1/3 inches long, commonly referred to as a "film leader", protrudes Erom a light-trapped slit or mouth of the cassette shell. One end of the spool has a short axial extension which pro~ects from the shell, enabling the spool to be turned by hand. If the spool is initially rotated in a film unwinding direction, ~he film roll inside the shell will tend to expand r~dially since the inner end of the filmstrip is a~tached to the spool, and the fogged leader section protrudin~ from the slit wlll remain 2S stationary. The film roll can expand radially untll non-slipping relation is established between its outermost convolutlon and the inner curved wall of the shell. Once this non-slipping relation exists, there is a binding effect between the film roll and the shell which prevents further rotation of ~he spool in the unwinding direction. Thus rotation of the spool in the unwinding direction cannot serve to advance the filmstrip out of the shell, and it is necessary to engage the protruding leader section to draw the filmstrip out of the shell.

.

1 30769~

I in the standard 35mm film manufacturers' cassette, the film spool is rotate~ in a winding direction suEflclently to drsw the protruding leader section of the filmstrip completely to within the cassette shell, it is very difficult to retrieve the leader section. U.S. Patent ~o. 4,407,~79, granted October 4, 1983, appears to solve this problem by providing a film cassette wherein manual rotation of the spool in the unwinding direction can serve to advance the ~ilm leader out of the cassette shell.
Specifically, the spool is comprised of two pieces constructed to telescopically receive one anotherO
Each piece includes a radially extending flange which is adapted to lie closely adjacent to but not in engagement wlth one of the opposite sides of the Film roll. A trailing end of the film roll i~
attached to the spool and a leadlng end of the roll rests against a cylindrical insert located between the two flanges and the cassette shell. ~he insert restricts the maximum diameter o the ~ilm roll to a vfltue less thfln the diameter of the flanges and includes a slot leading to the light-trapped film passage opening of the cassette shell. To move the leading end o~ the ~ilm roll into the slot and through the light-tr~pped opening, to make it ~vailable outside of the film cassette, one mus~
manually grasp the opposite ends of the spool and move the two pieces of the spool axially toward one another until the ~langes are axially positioned in firm contact with the opposite sides o~ the film roll. While maintaining this inwardly directed manual pressure agains~ the two pi~ces o~ the spool, one then must rotate the spool relative to the cassette shell in an unwinding direction. As a result, the leading end of the film roll will be ~ ., 1 :~(J~/69~

rotated relative to the insert, causing it to be advanced into the slot of the insert and through the light-trapped opening o~ the cassette shell to the outside of the film ca~sette.
Although the film cassette disclosed in U.S. Patent No. 4,407,579 includes an integral means whereby the leading end of the Eilm roll may be retrieved from within the cassette shell 9 operation of that means is difficult because it requires a fair amount of manual dexterity. Moveover, since the operation must be performed manually i~ can only be accomplished prior ~o loading the film cassette into a camera.
The invention advantageously solves the prior art problems described above by providing an improved film cassette wherein a film spool which, simply when rotated in a film unwinding direction, automatically advances the filmstrip out of the cassette shell. With such an improvement~ the prior flrt requirement for A protruding ~ilm leader is eliminated and the operation to retrieve the film leader from within the cAssette shell need not be performed m~nually.
According to the invention, there is generally provided an improved fllm cassette wherein (a) a cassette shell has a film passage opening, (b) a film spool is rotatable within the cassette shell in a film unwinding direction and has a pair of coaxially spaced radial flanges~ (c) a convoluted film roll is coiled about the spool between the two ~langes and h~s a film leader, (d) two parts of the spool are fixed to the respective flanges and ~t least one of the parts is movable axially toward the other part to move at least one of the flanges axially closer to the other flange and into a firm frictional relation with an outermost convolution of the film roll to thereby enable rotation of the spool in the unwinding direction to propel the film lader from the Film passage opening, and wherein the improvement comprises:
the two parts of the spool include cooperating means supporting the two parts for limited rotation of one of the parts relative to the other part in the unwinding direction to simultaneously move at least one part axially toward the o~her par~ un~il at least one of the flanges is moved into the firm frictional relation with the outermost convolution of the film roll, where~y further rotation of one of the part~ in the unwinding direction will rotate the spool in the same direction to propel the film leader from the ilm passage opening.
More specifically, the cooperating means includes respective rotation-responsive camming means located on the two parts of the ~pool for causing at least one of the parts to move axially toward the other part in response to rotation of one of the parts relative to the other part in the unwindinB
direction and for enablin~ the parts to rotate as a unlt in the unwinding direction after at least one of the flanges is moved into the firm frictional relation with the outermost convolution of the within the outermost convolutlon of the film roll.
The invention is preferably embodied in a 35mm film cassette wherein ~he leading end of the film roll coiled about the film spool is looated within the cassette shell. The film spool is comprised of two coaxial pieces constructed to telescopically receive one ~nother~ Each spool plece includes a radially extending flange normally , .
.

disposed sd~acent one of the opposite sides of the ~ilm roll. When the film spool is initially totated in a ~ilm unwindlng direction, a rotation-responsive cam device-coupling the two spool pieces automatically moves one spool piece axially toward the other piece to c~use the respect~ve flanges to clamp the film roll at its oppos1te sides. As a result, the leading end of the film roll will be rotated p~st a stripper-guide which strips the leading end ~rom between the flanges and guides it through a light-trapped opening in the cassette shell. Thus simply by rotating the film spool in the unwin~ing direction the leading end will automatically be advanced to the outside of the film cassette.
FIG. 1 is an explodsd perspective view of an improved film cassette according to a preferred embodiment o~ the invention, illustrating the two h~lves of a cassette shell and a film spool;
FlG. 2 is an elevation view of the improved ~ilm cassette, illustrating the film spool and one-half of the cassette shell; and FIG. 3 is an end view in cross-section of the improved film cassette.
The invention is disclosed as being embodied preferably in ~ 35mm film cassette.
Becaus~ the features of this type of film cassette are generally well known, the description which follows is directed in particular to elements forming part of or cooperatlng directly with the disclosed embodiment. It is to be understood, however, that other elements not speciflcally shown or described m~y taXe v~rious forms known to persons oF ordinary skill in the art.
Referring now to the drawings, FIGS. 1-3 1 3076q4 depict an improved 35mm film cassette 1 comprising a light-~ight cassette shell 3 and a ~ilm spool 5 rot~table about an axis X within the cassette shell. The cassette shell 3 consists of two shell halves 7 and 9 which are mated along respective stepped edge portions 11 and 13. The ma~ed halves 7 and 9 deE~ne upper and lower aligned openings lS and 17 for upper and lower opposite end extensions 19 and 21 of a spool core or hub 23. Also, they define a light-trapped film passage slit or mouth 25. The 11ght-trapp~ng means ~or preventing ambient light from entering the film passage slit 25, although not shown, may be a known flocking or plush material which lines the in~erior o~ the slit. One example lS of such a material is illustrated in U.S. Patent No.
4,~t07~579.
The spool core 23 as shown in FIG. 1 includes upper and lower coaxial holes 27 and 29 opening at the upper and lower opposite end extensions 19 and 21 of the spool core. A pair of spaced keying ribs 31 and 33 integrally formed with the spool core 23 are loc~ted within the lower coaxlal hole 29, and a single keying rlb 35 similarly ~ormed with the spool core is located within the upper coaxial hole 27. The several keying ribs 31, 33, and 35 according to custom may be engaged to rotate the film spool in an unwinding direction indlcated by the arrow U ln FIG. 1, or to rotate the spool in a winding direct~on opposite to the unwinding direction.
A roll 37 of convoluted 35mm ~ilm having a uni~orm width is wound about the spool core ~3. As indicated in FIGS. 1 and 3, the ~ilm roll 37 has an inner or tralling end 39 &ttached ko ~he spool core 23 by a suitable piece o~ adhesive tape 41 ~nd a 1 ~076q4 film leader 43. The film leader 43 has a leading or forward end 45 and comprises 2-3 convolutions of the film roll 37. One of these leader convolutions is the outermost convolution 47 and another of them is the next inward succeeding convolution 49.
A pair of identical flanges 51 and 53 radially ex~end~ng ~rom the spool core 23 are coaxially spaced ~o locate their respec~ive inner Eaces 55 and 57 ~dJacent opposite sides 61 and 63 of the ~ilm roll 37. See FIG. 2. The two 1anges 51 and 53 are slightly concave-shaped and are adapted to insure that ~he ~ilmstrip travels in direc~ions perpendlcul~r to the axis X of the ilm spool 5 as the ~ilmstr~p i~ unwound ~rom or rewound onto the ~ilm spool. As indicated in FI~. 1, the upper ~lange 51 is located beneath the upper opening 15 of the casse~te shell 3 and the lower flange 53 is lvcated above the lower opening 17 of the shell.
The maximum diameter of the film roll 37 ls restricted to a value less than the diameter of the two flanges 51 and 53 by two pairs o arcuate ribs 65, 67 and 69, 71, ~ixed to the two halves 7 and 9 of the c~ssette shell 3 at their respect~ve inner wall~ 73 and 75. The ~our ribs 65, 67, 69, and 71 protrude radially between the two flanges 51 and 53 to clrcumFerentially confine the ou~ermost convolution 47 oE the ~ilm roll 37 to thereby prevent the outermost convolution ~rom radially expanding or clock-springing beyond the peripheries o~ the ~langes to ~he shell walls 73 and 75. See FIGS. 1 and 2. PreEerably, the respective ribs 65, 67, 69, and 71 are relatively smooth at their respective areas o~ contac~ with the outermost convolution 47.
As shown in FIG. 1, ~he spool core 23 is comprised of two hollow cylindric~l coaxial pieces 77 and 79. The first spool piece 77 is integrally formed with the upper flange 51 and the second piece 79 is integrally for~ed with the lower flange 53.
An annular fixed insert 81 secured to the inside of the first spool piece 77 (or integrally formed therewith) is constructed to telescopically receive the second spool piece 79 in order to vary the axial dis~ance between the upper and lower Çlanges 51 ~nd 53. The specific means ~or varying the axial distance be~ween ~he two flanges 51 and 53 consists o~ an inclined cam edge or ramp 83 located on the ~nnular inser~ 81 and a cam follower tab 85 located on the second ~pool piece 79.
lS If the second spool piece 79 is initially rotated relative to the first spool piece 77 (including its annular insert 81) in the unwinding direction U, the interaction between the cam edge 83 and the ~ollower tab ~5 will cause the second spool piece to be further received within ~he annular insert, i.e~ the s~cond spool piece will be moved axlally toward the ~irst spool piece, thereby reducin~ the axial distance between the two flanges 51 and 53. The sccond spool piece 79 can be moved axially toward the ~irst spool piece 77 until the lower flange S3 is moved into a firm compressive relation with the one side 63 of the film roll 37.
At this time, the lower flange 53 preferably is disposed in abu~ment against a lower edge 87 of the annular insert 81. See FIG. 1. Moreover, the ~ollower tab 85 will have come to rest atop a plateau edge 89 and alongside a stop edge 91 of the : ann~lar insert 81. The stop edge 91 serves to prevent continued rotation of the second spool piece 79 relative to the first spool 77 (including its annular insert 81) in the unwinding direction U, thPreby causing ~urther rotation of the second spool piece in the unwinding direction to similarly rotate the ~irst spool piece. The plateau edge 89 serves to trap the f~llower tab ~S 1n order to secure the lower flange 53 ~n its compressive relation with the one side 63 of the film roll 37.
If the second spool plece 79 is rotated in a winding direction opposite to the unwinding d~rec~ion U a~ter its ~ollower tab 85 has come to rest atop the plateau edge ~9, the ~ollower tab will be moved o~ the plateau edge. Thus the lower ~lange 53 will no longer be secured in its comp~ ive ~ tion with the one side 63 of the ilm roll 37.
When the second spool piece 79 is initially rotated relative to the ~irst spool piece 77 (lncluding lts annular insert 81) in the unwindin~
direction U, the intera~tion between the cam edge 83 o~ the annular in~ert and the follower tab 85 of the second spool piece will cause the respective 1anges 51 and ~3 to ~i~mly clamp ~he film roll 37 a~ its opposite side~ 61 and 63. The outermost convolution 47 o~ the ilm roll 37 may be slightly transversely pinched becaus~ o~ the concave shape of the two Flange~ 51 and ~3. In any event, the leading end 45 o~ the ~ilm leader 4~ will tend to straighten longlt~di~ally and ~he~efore will slightly separate or li~t of~ tha outermost convolution 47. However, 3~ th~ ~our rib~ ~5, 67, 69, and 71 prevent the leading end 45 from contacting the shell walls 73 and 75.
Continued ro~ation o~ the second spo~l piece 79 in the unwinding direction U will similarly rotate the ~lrst ~pool piece 77. Moreover, the film roll 37 will be rotated in the unwinding direc~on U

-10- ' 1 3076q4 to advance its leading end 45 to a stripper-guide 93 integrally formed wi~h the cassette half 7. The stripper-guide ~3 then will ~trip the leading end 45 from between the two flanges Sl and 53 and guide it through the ~ilm passage sllt 25 to the outside of the cassette shell ~. Since the respective flanges 51 and 53 firmly clamp the film roll 37, especially along the outermost convolution 47, sufficient film thrust is provided to propel the leading end 45 past the stripper-guide 93 and out of the cassette shell 3.
The invention has been described with reference to a pre~erred embodiment. However, it will be appreciated that variations and modi~ications can be effected within the ordinary skill in the art without departing from the scope o~
the invention. For example, the respective inner ~aces 55 and 57 o~ ~he two ~langes Sl and 53 may be provided with a surface having a high coefficient of ~riction ~s suggested in U.S. Paten~ No. 4,407,579.

2~

: 35

Claims

1. A film cassette wherein a cassette shell has a film passage opening, a film spool is rotatable within said cassette shell in a film unwinding direction and has a pair of coaxially spaced radial flanges, a convoluted film roll is coiled about said spool between said two flanges and has a film leader, two parts of said spool are fixed to said respective flanges and at least one of said parts is movable axially toward the other part to move at least one of the flanges axially closer to the other flange and into a firm frictional relation with an outermost convolution of said film roll to thereby enable rotation of the spool in the unwinding direction to propel said film leader from said film passage opening, characterized in that:
said two parts of the spool include cooperating means supporting the two parts for limited rotation of one of said parts relative to the other part in the unwinding direction to simultaneously move at least one part axially toward the other part until at least one of said flanges is moved into said firm frictional relation with the outermost convolution of said film roll, whereby further rotation of one of said parts in the unwinding direction will rotate said spool in the same direction to propel said film leader from said film passage opening.

2. The film cassette as recited in claim 1, wherein said two flanges have respective faces located adjacent opposite sides of said film roll, each of said faces being slightly concave-shaped.

3. The film cassette as recited in claim 1 or 2, wherein said cooperating means includes rotation-responsive means located on said two parts of the spool for causing at least one of said parts to move axially toward the other part in response to rotation of one of the parts relative to the other part in the unwinding direction and for enabling said parts to rotate as a unit in the unwinding direction after at least one of said flanges is moved into said firm frictional relation with the outermost convolution of said film roll.

4. The film cassette as recited in claim 3, wherein said rotation-responsive means includes axial restraining means for maintaining said two parts of the spool in a fixed axial relation to prevent at least one of the parts from being moved axially away from the other part after at least one of said flanges is moved into said firm frictional relation with the outermost convolution of said film roll.

5. The film cassette as recited in claim 4, wherein said axial restraining means discontinues said fixed axial relation between the two parts of said spool in response to rotation of one of said parts relative to the other part in a film winding direction opposite to the unwinding direction.

6. The film cassette as recited in claim 1, wherein said cassette shell includes relatively low friction ribs which protrude between said two flanges to radially confine the outermost convolution of said film roll to thereby prevent said outermost convolution from radially expanding beyond the flanges to the cassette shell.

7. The film cassette as recited in claim 2 wherein said cooperating means includes rotation-responsive means located on said two parts of the spool for allowing rotation of one of said parts relative to the other part in the unwinding direction before at least one of said flanges is moved into said firm frictional relation with the outermost convolution of said film roll and for preventing rotation of one of said parts relative to the other part in the same direction after at least one of said flanges is moved into the frictional relation with said outermost convolution.

8. The film cassette as recited in claims 1 or 2 wherein said respective flanges are adapted to clamp said film roll at opposite sides of the roll when at least one of the flanges is positioned in said firm frictional relation with the outermost convolution of said film roll, and said cooperating means includes axial restraining means responsive to movement of at least one of said flanges into the frictional relation with said outermost convolution for establishing a fixed axial relation between said two parts of the spool to prevent said film roll from urging one of the flanges axially away from the other flange.

9. The film cassette as recited in claim 8, wherein said axial restraining means discontinues said fixed axial relation between said two parts of the spool in response to rotation of one of the parts relative to the other part in a film winding direction opposite to the unwinding direction to thereby allow said film roll to urge one of said flanges axially away from the other flange.