US3745863A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Severing mechanism
Assignee: Bell and Howell Co
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Filing: 1972-01-06
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Granted: 1973-07-17
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Expires: 1992-01-06
Abstract
Abstract A severing mechanism for cutting sheets or strips of paper or other sheet material from a length thereof, including a rotatably mounted knife spring biased in one direction of rotation for cutting purposes. An arcuate ratchet is mounted at one end of the knife. A cocking pawl is oscillatably mounted for incrementally rotating the knife to a cocked condition by engaging the ratchet teeth seriatim, and a keeper pawl is engageable with the ratchet teeth to prevent rotation of the knife on the back strokes of the oscillating cocking pawl. A cam type trip member engages the pawls to lift the pawls off of the ratchet, thereby releasing the knife for cutting. In one form of the invention, a lost motion connection is provided between the cocking and keeper pawls to permit the cocking pawl to oscillate relative to the keeper pawl for cocking the knife but to cause both of the pawls to be moved off of the ratchet when one of the pawls is tripped. In another form, the cocking pawl is moved off of the ratchet prior to the keeper pawl so that the oscillatory movement of the cocking pawl does not interfere with sharp release of the knife.
Inventors
- 👤 R Murre
- 👤 H Schulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:53
CPC Classifications
B; B26; B26D; B26D1/00; B26D1/01; B26D1/04; B26D1/045; B26D5/00; B26D5/08; B26D5/16; Y; Y10; Y10T; Y10T83/00; Y10T83/444; Y10T83/4496; Y10T83/4498; Y10T83/869; Y10T83/8776; Y10T83/8782; Y10T83/8784
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
A severing mechanism, comprising: a rotatably mounted knife; means biasing said knife in one direction of rotation for cutting purposes; ratchet means operatively associated with said rotary knife; pawl means engageable with said ratchet means to rotate said knife opposite said one dire(tion and hold the knife in a cocked condition; and trip means to disengage said pawl means from said ratchet means to release said knife and permit said biasing means to rotate the knife in said one direction for cutting purposes.
Claim 2
Dependent Claim
83 words
A severing mechanism, comprising: a rotatably mounted knife; means biasing said knife in one direction of rotation for cutting purposes; ratchet means operatively associated with said rotary knife; pawl means engageable with said ratchet means to rotate said knife opposite said one dire(tion and hold the knife in a cocked condition; and trip means to disengage said pawl means from said ratchet means to release said knife and permit said biasing means to rotate the knife in said one direction for cutting purposes.
Claim 3
Dependent Claim
63 words
The severing mechanism of claim 1 wherein said ratchet means includes a series of ratchet teeth, and said pawl means includes a cocking pawl oscillatably mounted for incrementally rotating said knife to its cocked condition by engaging said teeth seriatim and a keeper pawl engageable with said teeth to prevent rotation of said knife on the back strokes of said oscillating cocking pawl.
Claim 4
Dependent Claim
72 words
The severing mechanism of claim 2 including a lost motion connection means between said cocking and keeper pawls to permit said cocking pawl to oscillate relative to said keeper pawl when cocking said knife but to cause one of said pawls to lift off of said ratchet means when the other pawl is moved off of the ratchet in a direction transverse to the direction of oscillatory movement of said cocking pawl.
Claim 5
Dependent Claim
21 words
The severing mechanism of claim 3 including means biasing one of said pawls in said transverse direction against said ratchet means.
Claim 6
Dependent Claim
33 words
The severing mechanism of claim 3 wherein said trip means includes cam means on one of said pawls engageable by an appropriate complementary cam means to disengage said pawls from said ratchet means.
Claim 7
Dependent Claim
25 words
In combination with the severing mechanism of claim 5, a drive system which includes said trip means, said drive system including said complementary cam means.
Claim 8
Dependent Claim
67 words
The combination of claim 6 wherein said drive system includes an endless drive chain member having at least one protruding pin member fixed thereto at a point therealong, said pin member comprising said complementary cam means for engaging the cam means on said one pawl in response to movement of the drive chain member to trip the rotary knife in a timed relationship with said drive system.
Claim 9
Dependent Claim
63 words
The combination of claim 6 wherein said drive systEm includes a rotating member having at least one protruding pin member fixed thereto for rotation therewith, said pin member comprising said complementary cam means for engaging the cam means on said one pawl in response to rotation of said rotating member to trip the rotary knife in a timed relationship with said drive system.
Claim 10
Dependent Claim
58 words
The combination of claim 8 wherein said rotating member comprises a rotating gear in meshed engagement with a drivIng gear in said drive system, and including means to selectively disengage said gears to permit relative rotation therebetween and thereby adjust the point in time when said pin member will engage said cam means to trip the rotary knife.
Claim 11
Dependent Claim
46 words
The combination of claim 9 wherein said rotating gear is mounted for selective axial movement to provide for disengagement from said driving gear, and including means operatively associated with said rotating gear when disengaged from said driving gear to limit the relative rotation of the gears.
Claim 12
Dependent Claim
53 words
The combination of claim 10 wherein said last named means includes an annular slot in said rotating gear and a fixed pIn member which extends into the slot when the rotating gear is disengaged from said driving gear, the fixed pin member being removed from the slot when the gears are in mesh.
Claim 13
Dependent Claim
49 words
The combination of claim 2 wherein said ratchet means has an override portion at the end of said series of teeth providing a lost motion means between the ratchet means and said cocking pawl to permit the cocking pawl to continue to oscillate after said knife has been cocked.
Claim 14
Dependent Claim
59 words
The combination of claim 2 wherein said trip means includes a first portion operatively associated with one of said pawls and a second portion operatively associated with the other of said pawls and means to actuate said first portion prior to actuating said second portion to lift one pawl off of the ratchet means prior to the other pawl.
Claim 15
Dependent Claim
36 words
The combination of claim 13 wherein said trip means includes a rotating member having a pair of pins protruding from one side threof and comprising said first and second portions, said pins being slightly angularly separated.
Claim 16
Dependent Claim
52 words
The combination of claim 13 wherein said second portion of the trip means is operatively associated with said cocking pawl to lift the cocking pawl off of the ratchet means before the keeper pawl so that the oscillatory movement of the cocking pawl does not interfere with sharp release of said knife.
References Cited (Backward Citations)
US3185008A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |