US3747085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tool monitoring apparatus
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1971-11-03
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Granted: 1973-07-17
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Expires: 1991-11-03
Abstract
Abstract Apparatus for monitoring the condition of a tool and for detecting the improper operation thereof. The apparatus utilizes a magnetic circuit formed of a first low reluctance portion and a second high reluctance portion having a pulsating magnetic flux induced therein. In normal operation, the tool to be monitored is adapted to be positioned within and substantially bridge the high reluctance portion, which preferably comprises an air gap, and become a part of the circuit thus greatly lowering its reluctance. Appropriate electronics are provided to monitor abrupt and significant increases in the reluctance due to withdrawal of the tool from the air gap caused by breakage or loss of the tool. The sensing portion of the apparatus is manufactured as an enclosed unit which may be adapted to monitor tools of various types and sizes.
Inventors
- 👤 J Bala
- 👤 P Ford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:02
CPC Classifications
B; B23; B23Q; B23Q17/00; B23Q17/09; B23Q17/0904; B23Q17/0919; B23Q17/0947; B23B; B23B49/00; B23B49/001; Y; Y10; Y10T; Y10T408/00; Y10T408/13; Y10T408/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
151 words
Tool monitoring apparatus comprising: a. a housing; and b. sensing means positioned within said housing for sensing an elongated tool which may be of diverse widths and which is to be positioned through said housing and said sensing means, said sensing means including: 1. a magnetic circuit having a pair of aligned tapered pole portions between which an air gap for receipt of said tool to be sensed is to be formed by removing sufficient amounts of said tapered portions to provide an air gap having a width substantially identical to that of said tool to be sensed; 2. an input winding in inductive relationship with said circuit and having a pair of input terminals adapted to be coupled to a source of pulsating voltage; and 3. an output winding in inductive relationship with said circuit and having a pair of output terminals adapted to be coupled to a monitoring circuit.
Claim 2
Dependent Claim
151 words
Tool monitoring apparatus comprising: a. a housing; and b. sensing means positioned within said housing for sensing an elongated tool which may be of diverse widths and which is to be positioned through said housing and said sensing means, said sensing means including: 1. a magnetic circuit having a pair of aligned tapered pole portions between which an air gap for receipt of said tool to be sensed is to be formed by removing sufficient amounts of said tapered portions to provide an air gap having a width substantially identical to that of said tool to be sensed; 2. an input winding in inductive relationship with said circuit and having a pair of input terminals adapted to be coupled to a source of pulsating voltage; and 3. an output winding in inductive relationship with said circuit and having a pair of output terminals adapted to be coupled to a monitoring circuit.
Claim 3
Dependent Claim
27 words
an input winding in inductive relationship with said circuit and having a pair of input terminals adapted to be coupled to a source of pulsating voltage; and
Claim 4
Dependent Claim
27 words
an input winding in inductive relationship with said circuit and having a pair of input terminals adapted to be coupled to a source of pulsating voltage; and
Claim 5
Dependent Claim
38 words
Apparatus as recited in Claim 1 wherein said aligned tapered pole portions are joined together by a connecting portion which is adapted to be removed along with sufficient amounts of said tapered portions to form said air gap.
Claim 6
Dependent Claim
61 words
Apparatus as recited in Claim 1 wherein the narrowest ends of said tapered portions define the width of said air gap to be formed such that the width of said air gap may be adjusted in size to receive tools of different widths while ensuring substantial contact between said tool and said pole portions irrespective of the width of said tool.
Claim 7
Dependent Claim
24 words
an output winding in inductive relationship with said circuit and having a pair of output terminals adapted to be coupled to a monitoring circuit.
Claim 8
Dependent Claim
24 words
an output winding in inductive relationship with said circuit and having a pair of output terminals adapted to be coupled to a monitoring circuit.
Claim 9
Dependent Claim
31 words
Apparatus as recited in Claim 1 wherein said housing includes indicia means for identifying the position at which said air gap is to be formed through said housing and said circuit.
Claim 10
Independent Claim
114 words
A method for monitoring the condition of movable elongated tools which may be of diverse widths comprising the steps of: a. providing a magnetic circuit means through which said tool to be monitored is to be passed, said magnetic circuit means including a low reluctance portion; b. removing sufficient amounts of said low reluctance portion to provide an air gap having a width substantially identical to the width of the tool to be monitored; c. passing said tool to be monitored through said air gap; and d. monitoring the reluctance of said magnetic circuit means and generating a signal upon a change in the reluctance thereof indicative of the improper condition of said tool.
Claim 11
Independent Claim
114 words
A method for monitoring the condition of movable elongated tools which may be of diverse widths comprising the steps of: a. providing a magnetic circuit means through which said tool to be monitored is to be passed, said magnetic circuit means including a low reluctance portion; b. removing sufficient amounts of said low reluctance portion to provide an air gap having a width substantially identical to the width of the tool to be monitored; c. passing said tool to be monitored through said air gap; and d. monitoring the reluctance of said magnetic circuit means and generating a signal upon a change in the reluctance thereof indicative of the improper condition of said tool.
Claim 12
Dependent Claim
36 words
A method as recited in claim 5 wherein said tool to be monitored comprises a drill and wherein said removing step comprises drilling a hole through said low reluctance portion with said drill to be monitored.
Claim 13
Dependent Claim
54 words
A method as recited in claim 5 wherein said low reluctance portion includes a pair of aligned tapered pole portions and wherein said removing step comprises drilling away sufficient amounts of said pole portions to provide an air gap therebetween having a width substantially identical to the width of said tool to be monitored.
Claim 14
Dependent Claim
47 words
A method as recited in claim 5 wherein said magnetic circuit means is contained within a substantially enclosed housing and wherein said removing step comprises drilling through both said housing and said circuit means to provide said air gap for receipt of said tool to be monitored.
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) | 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 |