Patent US4581966A successfully refreshed from Google Patents.
US4581966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chop saw linkage system for moving saw guard
Assignee: Black and Decker Inc
•
Filing: 1985-04-16
•
Granted: 1986-04-15
•
Expires: 2005-04-16
Abstract
Abstract A chop saw pivotably mounted for movement between a raised rest position and a lowered operational position, having a motor driven saw-blade rotatably supported about a shaft, with a saw housing partially encasing the saw-blade and a swinging blade guard which covers the exposed segment of the saw-blade when the saw is in the rest position. When the saw is lowered to its operational position, a linkage system comprising four effective levers and four hinges clears the blade guard, thereby exposing the saw blade to the work piece. To accommodate changing the saw blade while the saw-unit is in its rest position, the effective length of one of the levers can be temporarily reduced, thereby clearing the blade guard from the exposed section of the saw blade. This provides easy access to the saw-blade to be changed.
Inventors
- 👤 Horst Kaiser
- 👤 Rainer Herting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:01
CPC Classifications
B; B23; B23Q; B23Q11/00; B23Q11/06; Y; Y10; Y10T; Y10T83/00; Y10T83/606; Y10T83/768; Y10T83/7734; Y10T83/7755; Y10T83/7788
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
252 words
In a chop saw pivotally mounted on a bearing bracket for movement between a lowered, operational position and a raised, rest position, having a motor driven saw blade rotatably supported on a shaft, a housing partially encasing the saw blade, and a swinging blade guard disposed to cover an exposed segment of the saw blade when the chop saw is in the rest position, the improvement being a linkage system for moving the blade guard in response to movement of the chop saw between the lowered and raised positions, such that the blade guard immovably covers said exposed segment when the chop saw is in the raised position and is moved to uncover said exposed segment when the chop saw is moved to the lowered position, said linkage system comprising; a frame member fixed to and extending upwardly from said bearing bracket; an actuation lever; first hinging means for pivotally mounting the housing near the base of said frame member; second hinging means pivotally attaching one end of said actuation lever to said frame member upwardly from said first hinging means; third hinging means pivotally attaching the other end of said actuating lever to the swinging blade guard; and fourth hinging means pivotably connecting said swinging blade guard to the housing; said third hinging means being eccentrically positioned on said blade guard with respect to said fourth hinging means and the distance between said third and fourth hinging means being subsantially less than the distance between said first and second hinging means.
Claim 2
Dependent Claim
252 words
In a chop saw pivotally mounted on a bearing bracket for movement between a lowered, operational position and a raised, rest position, having a motor driven saw blade rotatably supported on a shaft, a housing partially encasing the saw blade, and a swinging blade guard disposed to cover an exposed segment of the saw blade when the chop saw is in the rest position, the improvement being a linkage system for moving the blade guard in response to movement of the chop saw between the lowered and raised positions, such that the blade guard immovably covers said exposed segment when the chop saw is in the raised position and is moved to uncover said exposed segment when the chop saw is moved to the lowered position, said linkage system comprising; a frame member fixed to and extending upwardly from said bearing bracket; an actuation lever; first hinging means for pivotally mounting the housing near the base of said frame member; second hinging means pivotally attaching one end of said actuation lever to said frame member upwardly from said first hinging means; third hinging means pivotally attaching the other end of said actuating lever to the swinging blade guard; and fourth hinging means pivotably connecting said swinging blade guard to the housing; said third hinging means being eccentrically positioned on said blade guard with respect to said fourth hinging means and the distance between said third and fourth hinging means being subsantially less than the distance between said first and second hinging means.
Claim 3
Dependent Claim
54 words
The linkage system of claim 1 further comprising means for selectively disengaging said second hinging means to permit temporary shortening of the effective length of said actuation lever and moving of the blade guard to uncover said exposed segment when the chop saw is in the raised position for facilitating changing said saw blade.
Claim 4
Dependent Claim
142 words
The linkage system as recited in claim 2 wherein: said second hinging means is a pivot bolt having a shank received through a pivot point aperture in said actuation lever, and a threaded end section threadably secured to said frame member, said threaded end section having a diameter less then said shank; and said means for disengaging said second hinging means comprises an axial slot in said actuation lever adjoining the pivot point aperture, the width of said slot being less than the diameter of the shank of the pivot bolt and less than the diameter of said pivot point aperture and greater than the diameter of said threaded portion; and means for partially withdrawing the threaded end section of said pivot bolt from said frame member to dispose part of said threaded end section for slidable movement in said axial slot.
Claim 5
Dependent Claim
49 words
The linkage system as specified in claim 3 wherein said withdrawing means includes an opening in said housing providing access to the head of said pivot bolt when the chop saw is in the raised position permitting manual partial withdrawal of said threaded end section from said frame member.
Claim 6
Dependent Claim
67 words
The linkage system as specified in claim 4 wherein said opening includes a central bore of insufficient diameter to permit removal of said pivot bolt therethrough and an expanded inner cavity of sufficient diameter to receive the head of said pivot bolt and wherein disposition of the head of said pivot bolt in said inner cavity prevents the chop saw from being moved to the lowered position.
Claim 7
Dependent Claim
48 words
The linkage system as recited in claim 3 wherein said actuation level is L-shaped and is connected to said pivot bolt by its longer leg and is attached to the third hinging means by its shorter leg, permitting said linkage system to be essentially mounted in one plane.
Claim 8
Dependent Claim
28 words
The linkage system as defined in claim 6 wherein the axis of rotation of the fourth hinging means is the longitudinal axis of the shaft supporting the saw-blade.
Claim 9
Dependent Claim
27 words
The linkage system as specified in claim 3 further comprising a locking means for detachably engaging the actuation lever when the saw is in the raised position.
References Cited (Backward Citations)
US3821918A
Cited
DE7420476U
Cited
US3994192A
Cited
FR2312327A1
Cited
US4002094A
Cited
US4028975A
Cited
DE2829297A1
Cited
US4318324A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |