US3911652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety blade for rotary lawn mowers
Assignee: Individual
•
Filing: 1974-01-11
•
Granted: 1975-10-14
•
Expires: 1994-01-11
Abstract
Abstract An improvement over a safety blade for rotary lawn mowers as disclosed in U.S. Pat. No. 3,545,189 comprising a blade assembly having a rigid metal member encapsulated in alternate layers of bonding rubber and high tensil fabric material and where the bonding layers and fabric material extend beyond opposite ends of the metal layer and wherein the metal layer is completely encapsulated by the rubber-like bonding material and the high tensil fabric material of the assembly. The disclosure also relating to a method of producing the blade assembly and to indicia molded on the blade assembly relating to precise cut off positions for cutting opposite ends of the blade assembly away to match the diametrical dimensions of various rotary lawn mowers.
Inventors
- 👤 Elmer R Houle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:06
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D34/73
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
128 words
In a safety blade for rotary lawn mowers, the combination of: a blade assembly having opposite ends and a middle portion; said middle portion having a shaft receiving opening adapted to be disposed over and fixed to a motor driven shaft on a substantially vertical rotary axis; said blade assembly having a corresponding rotary axis and blade assembly comprising at least one rigid metal layer; fabric layers; and resilient rubber-like layers of material bonded to and securing said fabric layers and said metal layer together; said metal layer being encapsulated between said fabric layers and said layers of rubber-like material; said metal layer having opposite ends terminating in spaced relation to said opposite ends of said blade assembly and corresponding opposite ends of said fabric and rubberlike layers.
Claim 2
Dependent Claim
128 words
In a safety blade for rotary lawn mowers, the combination of: a blade assembly having opposite ends and a middle portion; said middle portion having a shaft receiving opening adapted to be disposed over and fixed to a motor driven shaft on a substantially vertical rotary axis; said blade assembly having a corresponding rotary axis and blade assembly comprising at least one rigid metal layer; fabric layers; and resilient rubber-like layers of material bonded to and securing said fabric layers and said metal layer together; said metal layer being encapsulated between said fabric layers and said layers of rubber-like material; said metal layer having opposite ends terminating in spaced relation to said opposite ends of said blade assembly and corresponding opposite ends of said fabric and rubberlike layers.
Claim 3
Dependent Claim
52 words
The invention as defined in claim 1 wherein said middle portion of said assembly is provided with said shaft receiving opening therethrough for receiving a motor driven shaft therein on said rotary axis; and means on said assembly adapted to prevent rotation of said blade assembly around said shaft and relative thereto.
Claim 4
Dependent Claim
29 words
The invention as defined in claim 2 wherein said opening comprises a plurality of concentric and varying in diameter knock out portions adapted to fit shafts of various diameters.
Claim 5
Dependent Claim
45 words
The invention as defined in claim 1 wherein said blade assembly is provided with portions extending beyond the ends of said metal layer; said last mentioned portions being provided with upper and lower surfaces disposed at angles of less than 90* to said rotary axis.
Claim 6
Dependent Claim
42 words
The invention as defined in claim 1 wherein said metal member is made of carburized steel having a brittle character adapted to break and to allow said blade assembly to fold when the assembly hits an object of substantial size and rigidity.
Claim 7
Dependent Claim
43 words
The invention as defined in claim 1 wherein said blade assembly is provided with drive member receiving openings spaced from said shaft receiving opening and thereby adapted to prevent rotation of said blade assembly relative to a shaft on which it is mounted.
Claim 8
Independent Claim
117 words
A method for producing a safety blade for rotary lawn mowers comprising preparing a substantially metal layer having opposite ends; laying rubber-like bonding layers at opposite sides of said metal layer and applying alternate fabric and rubber-like bonding layers to said rubber-like bonding layer with portions of said fabric and rubber-like layers extending beyond said opposite ends of said metal layer and placing said metal layer, all of said fabric layers and all of said rubber-like layers in a mold in the foregoing disposition; then applying heat and pressure by said mold for compacting and vulcanizing all of said layers together in securely bonded relation to each other thereby forming a safety blade assembly for lawn mowers.
Claim 9
Independent Claim
117 words
A method for producing a safety blade for rotary lawn mowers comprising preparing a substantially metal layer having opposite ends; laying rubber-like bonding layers at opposite sides of said metal layer and applying alternate fabric and rubber-like bonding layers to said rubber-like bonding layer with portions of said fabric and rubber-like layers extending beyond said opposite ends of said metal layer and placing said metal layer, all of said fabric layers and all of said rubber-like layers in a mold in the foregoing disposition; then applying heat and pressure by said mold for compacting and vulcanizing all of said layers together in securely bonded relation to each other thereby forming a safety blade assembly for lawn mowers.
Claim 10
Independent Claim
161 words
A method for producing a safety blade for rotary lawn mowers comprising preparing a substantially rigid metal layer having opposite ends; laying rubber-like bonding layers at opposite sides of said layer and applying alternate fabric and rubber-like bonding layers to said rubber-like bonding layer with portions of the fabric and rubber-like layers extending beyonD said opposite ends of said metal layer; placing additional fabric layers and corresponding rubber-like bonding layers in overlapping relation to said ends of said metal layer and disposing said additional fabric layers so as to extend beyond the ends of said metal layer towards said opposite ends of said blade assembly; and placing said metal layer, all of said fabric layers and all of said rubber-like layers in a mold in the foregoing disposition; then applying heat and pressure by said mold for compacting and vulcanizing all of said layers together in securely bonded relation to each other thereby forming a safety blade for rotary lawn mowers.
Claim 11
Independent Claim
161 words
A method for producing a safety blade for rotary lawn mowers comprising preparing a substantially rigid metal layer having opposite ends; laying rubber-like bonding layers at opposite sides of said layer and applying alternate fabric and rubber-like bonding layers to said rubber-like bonding layer with portions of the fabric and rubber-like layers extending beyonD said opposite ends of said metal layer; placing additional fabric layers and corresponding rubber-like bonding layers in overlapping relation to said ends of said metal layer and disposing said additional fabric layers so as to extend beyond the ends of said metal layer towards said opposite ends of said blade assembly; and placing said metal layer, all of said fabric layers and all of said rubber-like layers in a mold in the foregoing disposition; then applying heat and pressure by said mold for compacting and vulcanizing all of said layers together in securely bonded relation to each other thereby forming a safety blade for rotary lawn mowers.
Claim 12
Dependent Claim
36 words
The invention as defined in claim 8 comprising the molding of an opening in the middle of said blade assembly with a plurality of varying diameter knock out portions for fitting various shafts of various diameters.
References Cited (Backward Citations)
US3302377A
Cited
US3340682A
Cited
US3402542A
Cited
US3465508A
Cited
US3545189A
Cited
US3516236A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |