US3653702A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety lock device
Assignee: Polymer Machinery Corp
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Filing: 1970-11-12
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Granted: 1972-04-04
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Expires: 1990-11-12
Abstract
Abstract A safety interlock arrangement for the protective cover of an electrical motor driven grinder or the like whereby the power to the motor is cut off when the protective cover is not in its normally closed position and fastened to the base of the grinder. The interlocking arrangement includes a screw which is mounted on the side of the protective cover and which engages the base or support for the grinder to lock the protective cover in its closed position. A bearing block, containing a mercury switch which controls the power input into the electric motor, is pivotally mounted on the side of the protective cover so that it normally rests against the free end of the screw. In order to disengage the screw from the base, the bearing block must be pivoted to a position wherein the mercury switch is open, thus disconnecting the power from the electric motor.
Inventors
- 👤 Herbert H Frimberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:32
CPC Classifications
F; F16; F16P; F16P3/00; F16P3/08; B; B24; B24B; B24B55/00; B24B55/04; H; H01; H01H; H01H9/00; H01H9/20; H01H9/22; H01H9/226; Y; Y10; Y10T; Y10T292/00; Y10T292/08; Y10T292/1099
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
268 words
A safety interlocking arrangement for an electrical motor driven grinder or the like, comprising in combination: a protective cover for said grinder pivotally mounted on the base of said grinder for movement between a normally closed position and an open position; a rod mounted on an external side surface of said cover so that it is at least slidable along its longitudinal axis, said rod having fastening means at one end and having a handle with a bearing surface at the other end thereof; means provided on said base of said grinder for engaging said fastening means on said rod when said cover is in a closed position to lock said cover to said base; a bearing block pivotally mounted on said side surface of said cover adjacent said other end of said rod so that said bearing block is free to pivot between a first normal position wherein it rests on said bearing surface, and a second position wherein said block is out of the axial travel path of said rod; and a mercury switch securely mounted within said bearing block so that said switch is closed when said bearing block is in said first position and said rod is securely engaged with said base, and is open when said bearing block is in said second position, said mercury switch being connected in and controlling the operation of the power supply circuit for the electric motor driving said grinder, whereby power can be delivered to said grinder only when said cover is in its normally closed position and securely fastened to said grinder base via said rod.
Claim 2
Dependent Claim
268 words
A safety interlocking arrangement for an electrical motor driven grinder or the like, comprising in combination: a protective cover for said grinder pivotally mounted on the base of said grinder for movement between a normally closed position and an open position; a rod mounted on an external side surface of said cover so that it is at least slidable along its longitudinal axis, said rod having fastening means at one end and having a handle with a bearing surface at the other end thereof; means provided on said base of said grinder for engaging said fastening means on said rod when said cover is in a closed position to lock said cover to said base; a bearing block pivotally mounted on said side surface of said cover adjacent said other end of said rod so that said bearing block is free to pivot between a first normal position wherein it rests on said bearing surface, and a second position wherein said block is out of the axial travel path of said rod; and a mercury switch securely mounted within said bearing block so that said switch is closed when said bearing block is in said first position and said rod is securely engaged with said base, and is open when said bearing block is in said second position, said mercury switch being connected in and controlling the operation of the power supply circuit for the electric motor driving said grinder, whereby power can be delivered to said grinder only when said cover is in its normally closed position and securely fastened to said grinder base via said rod.
Claim 3
Dependent Claim
66 words
The apparatus as defined in claim 1 further comprising a spring coaxially mounted on said rod so that said spring is compressed when said rod is fastened to said grinder base, said spring causing said rod to move along its longitudinal axis to a position wherein said bearing block is prevented from being pivoted into its first position when said rod is disengaged from said base.
Claim 4
Dependent Claim
22 words
The apparatus as defined in claim 2 wherein said rod is mounted so that it is also rotatable about its longitudinal axis.
Claim 5
Dependent Claim
31 words
The apparatus as defined in claim 2 wherein said fastening means comprises a threaded portion of said rod, and wherein said means for engaging said fastening means is a threaded bore.
Claim 6
Dependent Claim
64 words
The apparatus as defined in claim 4 wherein the length of the threaded portion of said rod engaged by said threaded bore when said cover is securely locked in its closed position is such that the time required to disengage said rod from said bore, after pivoting said bearing block to said second position, is sufficient to allow said grinder to come to rest.
Claim 7
Dependent Claim
30 words
The apparatus as defined in claim 2 wherein said cover and said bearing block pivot about parallel axes and in the same direction to and from their respective normal positions.
Claim 8
Dependent Claim
43 words
The apparatus as defined in claim 6 wherein said cover and said bearing block pivot about substantially horizontal axes, wherein said rod is mounted in a substantially vertical plane, and wherein said bearing block is substantially horizontal when in its said normal position.
Claim 9
Dependent Claim
43 words
The apparatus as defined in claim 2 including stop means for limiting the rotation of said bearing block when it is in said second position to prevent said mercury switch from assuming a position other than said first position wherein it is closed.
Claim 10
Dependent Claim
105 words
The apparatus as defined in claim 3 wherein said rod is mounted on said cover by means of an arrangement including: a flange securely fastened to said side surface of said cover and extending laterally therefrom, and a tube securely fastened to said flange and having a cap, which is provided with a central opening, on at least the lower end thereof, said rod extending coaxially through said tube and said opening; and wherein said spring is disposed at least partially within said tube with one end thereof bearing against the inner surface of said cap, and the other end thereof bearing against said handle.
Claim 11
Dependent Claim
52 words
The apparatus as defined in claim 9 wherein said cover and said bearing block pivot about substantially horizontal axes and in the same direction to and from their respective normal positions; said rod is mounted in a substantially vertical plane; and said bearing block is substantially horizontal when in its normal position.
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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |