US3821918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motorized miter box
Assignee: Delta International Machinery Corp
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Filing: 1972-09-01
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Granted: 1974-07-02
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Expires: 1992-09-01
Abstract
Abstract A motorized miter box including a support base mounting an angularly adjustable support arm the rear end of which carries a forwardly and downwardly swingable motor driven saw means and the front end of which extends beyond and upwardly and inwardly around the arcuate web-run to form pointer means and quick acting detent means for adjustably setting the support arm to the frequently used miter cutting angles. The support for the swingable motor driven saw means includes compression spring biasing means for maintaining the motor driven saw means in its upper rest position including guide means for supporting the biasing spring, in event of spring failure, in partial operative position to arrest movement of the motor driven saw means to its operative position thereby assuring the operator against injury.
Inventors
- 👤 E Niehaus
- 👤 H Benney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:38
CPC Classifications
B; B27; B27G; B27G5/00; B27G5/02; B27G5/023; B23; B23D; B23D45/00; B23D45/04; B23D45/042; B23D45/044; B27B; B27B5/00; B27B5/16; B27B5/18; B27B5/20; B27B5/206; B27G19/00; B27G19/02; B27G19/025; Y; Y10; Y10T; Y10T83/00; Y10T83/768; Y10T83/7684; Y10T83/7693; Y10T83/7697; Y10T83/7722; Y10T83/7726; Y10T83/7755; Y10T83/7788
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
283 words
A motorized miter box having a base structure comprising side walls joined at opposed upper corners by an arcuate forwardly protruding web-like run and further joined in spaced relation below said web-like run by diagonally directed ribs intersecting in the medial plane between said side walls to define a vertical journal bore; a support member journalled in said journal bore and having a first arm extending radially rearwardly from the axis of said journal bore formed to pivotally mount motor driven saw means for swinging movement from a normal rest position to and through a cutting zone terminating slightly above the plane defined by the upper faces of said side walls and an oppositely directed arm extending beneath and terminating beyond the forward edge of said arcuate web-run in an upstanding inturned hookshaped end formation freely passing the arcuate marginal edge of said web-run, said inturned end of said hook-shaped end formation being through apertured and tapped in overlying relation to said upper marginal edge of said web-run and fitted with a set screw adapted to be selectively engaged with the upper marginal face of said web-run to secure said support member in any angularly adjusted position thereby to position said motor driven saw means for selectively cutting workpieces spanning said base structure side walls at a predetermined angle, and wherein said motor driven saw means is carried by a pivot shaft journalled in said first arm and coil compression spring biasing means, including a guide shaft extending lengthwise through the coils of said compression spring to support said compression spring in operative relation in event of spring failure, is provided to normally bias said motor driven saw means to its rest position.
Claim 2
Dependent Claim
283 words
A motorized miter box having a base structure comprising side walls joined at opposed upper corners by an arcuate forwardly protruding web-like run and further joined in spaced relation below said web-like run by diagonally directed ribs intersecting in the medial plane between said side walls to define a vertical journal bore; a support member journalled in said journal bore and having a first arm extending radially rearwardly from the axis of said journal bore formed to pivotally mount motor driven saw means for swinging movement from a normal rest position to and through a cutting zone terminating slightly above the plane defined by the upper faces of said side walls and an oppositely directed arm extending beneath and terminating beyond the forward edge of said arcuate web-run in an upstanding inturned hookshaped end formation freely passing the arcuate marginal edge of said web-run, said inturned end of said hook-shaped end formation being through apertured and tapped in overlying relation to said upper marginal edge of said web-run and fitted with a set screw adapted to be selectively engaged with the upper marginal face of said web-run to secure said support member in any angularly adjusted position thereby to position said motor driven saw means for selectively cutting workpieces spanning said base structure side walls at a predetermined angle, and wherein said motor driven saw means is carried by a pivot shaft journalled in said first arm and coil compression spring biasing means, including a guide shaft extending lengthwise through the coils of said compression spring to support said compression spring in operative relation in event of spring failure, is provided to normally bias said motor driven saw means to its rest position.
Claim 3
Dependent Claim
225 words
The motorized miter box improvement of claim 1 wherein said first arm of said support member at its free end is formed to provide a housing having laterally spaced, upstanding side walls formed adjacent their upper ends with coaxially opposed journal passages and interconnected at their opposite ends by respective end walls formed at their lower ends with coaxially aligned axial passages; a cross shaft is journalled in said opposed side wall journal passages with its opposite ends protruding beyond said side walls and rotatably mounts between said side walls; a downwardly inclined arm terminating in a bifurcated free end disposed in straddling relation to said guide shafT and fixedly mounts on one protruding end a support arm mounting said motor driven saw means in position to swing said bifurcated end of said inclined arm axially along said guide shaft; said compression spring encloses said guide shaft between said bifurcated end of said downwardly inclined arm and the housing end wall toward which said bifurcated end swings under the influence of said motor driven saw means whereby in event of structural failure of the compression spring, said guide shaft will effectively support the spring coils in axial interfering relation so as to maintain a sufficient spring resistence to constrain downward movement of said motor driven saw means to prevent its gravitation to said cutting zone.
Claim 4
Dependent Claim
118 words
The motorized miter box of claim 2 wherein said motor driven saw means swings downwardly and forwardly relative to said base structure, said base structure side walls have respective paired, tapped, laterally aligned passages opening through their upper edges forwardly of said vertical journal bore adapted to receive respective securing screws for securing the opposite ends of a non-metallic workpiece support block in spanning relation to said side walls in the path of downward movement of said motor driven saw means to support a workpiece to be cut, and said compression spring means is designed to extablish the end of the cutting zone at a point slightly below the work support surface of said non-metallic workpiece support block.
Claim 5
Dependent Claim
95 words
The motorized miter box of claim 2 wherein said base structure side walls have respective laterally aligned passages opening through their upper edges rearwardly of said vertical journal bore adapted to receive respective securing screws for securing the opposite ends of a workpiece guide fence in spanning relation to said side walls, said guide fence having an upstanding workpiece abutment flange disposed to engage the rear face of said non-metallic workpiece support block and having a laterally centered through slot opening through its top edge and lying in the cutting plane of said saw blade.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-01 | 1977-12-31 | 1978-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-01 | 1981-12-31 | 1982-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-01 | 1985-12-31 | 1986-07-02 | $7700.00 | Window Closed / Lapsed |