US3718822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rivet center detecting mechanism
Assignee: Rohr Inc
•
Filing: 1971-04-23
•
Granted: 1973-02-27
•
Expires: 1991-04-23
Abstract
Abstract To determine whether or not a rivet has been delivered to, and is properly centered between, the rivet holding fingers of an automatic riveting machine, a light beam is directed from a light source on one side of a selected rivet position, past such selected position toward two photocells, so positioned that both photocells are fully exposed to the beam when the fingers are empty; both photocells are shielded equally from the beam when a rivet is held in properly centered position between the fingers; and one of the photocells is exposed to the beam to a greater degree than the other when a rivet is in improperly centered position between the fingers. The photocells are embodied in a bridged circuit having three detectors responsive thereto, the detectors being actuated selectively according to the relatively illuminated condition of the photocells.
Inventors
- 👤 L Pascoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:10
CPC Classifications
B; B21; B21J; B21J15/00; B21J15/10; B21J15/30; B21J15/32; B21J15/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
230 words
Center detector mechanism for detecting, respectively, the centered, uncentered, or absence condition of an object of known size with respect to a beamed field having a known center and beam width, said mechanism comprising means for setting up said beamed field, means for holding and positioning the object normally in properly centered position in said field at a predetermined position therein wherein the object size has a predetermined relation to the beam width, variable resistance means for sensing the intensity of the beamed field which passes said predetermined position therein, said sensing means being actuated to a first known resistance condition by the absence of such object from the beamed field, to a secoNd known resistance condition by the presence of such object in improperly centered position in the field, and to a third known condition by the presence of the object in properly centered position in the field, a bridged circuit embodying said sensing means, said circuit being balanced with the sensing means in its first and third known resistance conditions, and unbalanced with the sensing means in its second known resistance condition, detector means responsive to said first and second conditions of the sensing means, and means actuated by said detector means for indicating said first and second conditions of the sensing means, said third condition of said sensing means being indicated by nonactuation of said indicating means.
Claim 2
Dependent Claim
230 words
Center detector mechanism for detecting, respectively, the centered, uncentered, or absence condition of an object of known size with respect to a beamed field having a known center and beam width, said mechanism comprising means for setting up said beamed field, means for holding and positioning the object normally in properly centered position in said field at a predetermined position therein wherein the object size has a predetermined relation to the beam width, variable resistance means for sensing the intensity of the beamed field which passes said predetermined position therein, said sensing means being actuated to a first known resistance condition by the absence of such object from the beamed field, to a secoNd known resistance condition by the presence of such object in improperly centered position in the field, and to a third known condition by the presence of the object in properly centered position in the field, a bridged circuit embodying said sensing means, said circuit being balanced with the sensing means in its first and third known resistance conditions, and unbalanced with the sensing means in its second known resistance condition, detector means responsive to said first and second conditions of the sensing means, and means actuated by said detector means for indicating said first and second conditions of the sensing means, said third condition of said sensing means being indicated by nonactuation of said indicating means.
Claim 3
Dependent Claim
21 words
Center detector mechanism as defined in claim 1 wherein separate detector means is responsive to each unbalanced condition of the circuit.
Claim 4
Dependent Claim
131 words
Center detector mechanism as claimed in claim 2 wherein the sensing means comprises a light source directing a beam of light toward such object centered in such field, and a pair of photocells incorporated in opposite sides of such circuit and mounted beyond such centered object from the light source, said photocells spaced equally on opposite sides of a line from the light source through the center of such object, said photocells being located to be equally shielded from the light from the light source by such object properly centered in such field, to be unequally shielded from the light from the light source by such object improperly centered in such field, and to be fully exposed to the light from such light source with such object absent from such field.
Claim 5
Dependent Claim
54 words
Center detector mechanism as claimed in claim 1 wherein the object is a rivet and the mechanism is for an automatic riveting machine having a pair of rivet holding fingers for receiving a rivet of known size in properly centered relation therebetween, and means biasing the fingers toward each other to rivet holding position.
Claim 6
Dependent Claim
138 words
Rivet center detector mechanism as claimed in claim 4 wherein the variable resistance sensing means comprises a light source directing a beam of light toward the axis of such rivet in properly centered position between the fingers, and a pair of photocells incorporated in opposite sides of said circuit and mounted beyond such properly centered rivet from the light source, said photocells spaced equally on opposite sides of a line from the light source through the axis of such properly centered rivet, said photocells being located to be equally shielded from the light from said light source by such properly centered rivet, to be unequally shielded from the light from said light source by such rivet improperly centered between the fingers, and to be fully exposed to the light from said light source when said fingers are empty.
Claim 7
Dependent Claim
40 words
Rivet center detector mechanism as claimed in claim 5 wherein the rivet holding fingers have opposed, complementary recesses therein for receiving a rivet of known size in properly centered, position between the fingers and in seated relation in the recesses.
Claim 8
Dependent Claim
33 words
A rivet center detector as claimed in claim 5 wherein the photocells are mounted substantially on the boundary zone between the umbra and penumbra of a shadow cast by such properly centered rivet.
References Cited (Backward Citations)
US3348057A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |