US3568636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot melt applicator system
Assignee: Lockwood Technical Inc
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Filing: 1968-05-15
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Granted: 1971-03-09
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Expires: 1988-05-15
Abstract
Abstract A liquid such as hot melt adhesive is supplied at a controlled superatmospheric pressure to the wheel chamber of a wheel-type applicator. The wheel chamber is so formed that liquid can overflow only by passing through a narrow annular channel between the working face of the wheel where it enters the chamber and an opposing chamber wall. Wheel rotation produces shearing action in the liquid in that channel, raising the pressure in the main body of the chamber. As the channel fills, that shear pressure exceeds the controlled supply pressure, positively preventing overflow during wheel rotation. The controlled supply pressure may be obtained by passing the liquid through an accumulator in which a controlled pressure is maintained by a pressure regulating valve, that pressure being automatically relieved when the wheel stops. Alternatively, liquid may be supplied to the wheel chamber via two valves that are driven with the wheel to open alternately, thus terminating supply in absence of wheel rotation. Another aspect of the invention provides a narrow annular channel at the wheel surface between the liquid inlet to the wheel chamber and the doctor blade or equivalent. Wheel rotation then produces at the doctor device a pressure that is higher than the supply pressure. Such enhanced pressure is especially useful with a wheel of intaglio type.
Inventors
- 👤 Glynn H Lockwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:46
CPC Classifications
B; B05; B05C; B05C1/00; B05C1/04; B05C1/08; B05C1/0813; B05C1/003; B05C1/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
310 words
In an applicator for a viscous liquid, said applicator including an applicator wheel mounted for rotation in a forward direction wIth respect to a wheel axis and having a generally cylindrical convex metering surface, structure forming with a limited portion of the wheel surface a chamber for containing the viscous liquid, said structure including an inlet port opening into the chamber and a doctor device for metering the liquid onto the wheel surface as it leaves the chamber; the improvement characterized in that: said chamber-forming structure includes a generally cylindrical concave chamber wall opposedly spaced from the wheel surface and forming with that surface an annular channel that extends through an appreciable arc with respect to the wheel axis between where the wheel surface enters the chamber and said inlet port, the radial dimension of the channel being sufficiently small that wheel rotation exerts upon liquid in the channel a viscous drag in the direction of wheel rotation and thereby produces at the inlet port a superatmospheric pressure that increases with wheel speed and with the circumferential length of channel that is filled with liquid; said applicator includes means for driving the wheel at a normal speed at which said pressure has a predetermined critical value when the channel is filled with liquid; means for supplying liquid to the inlet port essentially continuously during such wheel rotation at a controlled superatmospheric pressure that is less than said critical pressure; said liquid supplying means comprising a supply chamber containing liquid at said controlled pressure; conduit means for conducting liquid from the supply chamber to the first said chamber, said conduit means including two valve means acting in series; and means driven with the wheel rotation for opening the valve means intermittently and alternately, at least one valve means being always closed; whereby liquid supply is terminated in absence of wheel rotation.
Claim 2
Dependent Claim
310 words
In an applicator for a viscous liquid, said applicator including an applicator wheel mounted for rotation in a forward direction wIth respect to a wheel axis and having a generally cylindrical convex metering surface, structure forming with a limited portion of the wheel surface a chamber for containing the viscous liquid, said structure including an inlet port opening into the chamber and a doctor device for metering the liquid onto the wheel surface as it leaves the chamber; the improvement characterized in that: said chamber-forming structure includes a generally cylindrical concave chamber wall opposedly spaced from the wheel surface and forming with that surface an annular channel that extends through an appreciable arc with respect to the wheel axis between where the wheel surface enters the chamber and said inlet port, the radial dimension of the channel being sufficiently small that wheel rotation exerts upon liquid in the channel a viscous drag in the direction of wheel rotation and thereby produces at the inlet port a superatmospheric pressure that increases with wheel speed and with the circumferential length of channel that is filled with liquid; said applicator includes means for driving the wheel at a normal speed at which said pressure has a predetermined critical value when the channel is filled with liquid; means for supplying liquid to the inlet port essentially continuously during such wheel rotation at a controlled superatmospheric pressure that is less than said critical pressure; said liquid supplying means comprising a supply chamber containing liquid at said controlled pressure; conduit means for conducting liquid from the supply chamber to the first said chamber, said conduit means including two valve means acting in series; and means driven with the wheel rotation for opening the valve means intermittently and alternately, at least one valve means being always closed; whereby liquid supply is terminated in absence of wheel rotation.
Claim 3
Dependent Claim
32 words
The improvement defined in claim 1, and in which said valve means are arranged to supply air to the conduit portion between the valve means at least when said channel is empty.
Claim 4
Dependent Claim
217 words
Mechanism for supplying a liquid to an applicator that comprises a wheel assembly including an applicator wheel mounted for rotation in a forward direction with respect to an axis, structure forming with a limited portion of the wheel surface a wheel chamber for containing the liquid, and a doctor device for metering the liquid carried by the wheel surface as it leaves the chamber; said mechanism comprising in combination: a supply chamber for containing liquid at a pressure head sufficient to move liquid to the wheel chamber to raise the liquid level therein above the minimum level at which liquid just wets the wheel surface; structure forming a valve chamber at least partially recessed in the wheel assembly and having port structure that opens to the supply chamber when the wheel assembly is within one angular range of its rotation, and opens to the wheel chamber when the wheel assembly is within another angular range of its rotation, said two angular ranges being nonoverlapping; and the port structure that opens to the wheel chamber being at least partially above the minimum liquid level at which liquid just wets the wheel surface, whereby air is admitted increasingly from the wheel chamber into the valve chamber as the liquid level in the wheel chamber decreases toward said minimum level.
Claim 5
Dependent Claim
217 words
Mechanism for supplying a liquid to an applicator that comprises a wheel assembly including an applicator wheel mounted for rotation in a forward direction with respect to an axis, structure forming with a limited portion of the wheel surface a wheel chamber for containing the liquid, and a doctor device for metering the liquid carried by the wheel surface as it leaves the chamber; said mechanism comprising in combination: a supply chamber for containing liquid at a pressure head sufficient to move liquid to the wheel chamber to raise the liquid level therein above the minimum level at which liquid just wets the wheel surface; structure forming a valve chamber at least partially recessed in the wheel assembly and having port structure that opens to the supply chamber when the wheel assembly is within one angular range of its rotation, and opens to the wheel chamber when the wheel assembly is within another angular range of its rotation, said two angular ranges being nonoverlapping; and the port structure that opens to the wheel chamber being at least partially above the minimum liquid level at which liquid just wets the wheel surface, whereby air is admitted increasingly from the wheel chamber into the valve chamber as the liquid level in the wheel chamber decreases toward said minimum level.
Claim 6
Dependent Claim
77 words
The combination defined in claim 3, and in which: said wheel assembly includes a shaft on which said wheel is mounted, the wheel having an axial face; and said valve chamber comprises a generally axial passage within the wheel assembly opening radially to the supply chamber through first port structure in the shaft wall and opening axially to the wheel chamber through second port structure in the axial face of the wheel radially offset from the axis.
Claim 7
Dependent Claim
39 words
The combination defined in claim 3, and in which: said wheel has an axial face; and said valve chamber is formed in the wheel with said port stRucture opening through the axial wheel face radially offset from the axis.
Claim 8
Dependent Claim
83 words
The combination defined in claim 3, and in which: the valve chamber is so related to the port structure that opening of the port structure to the wheel chamber releases air from the valve chamber to the wheel chamber when the surface level therein is above the open port structure, absence of air in the valve chamber terminating liquid supply from the supply chamber to the wheel chamber; and the wheel chamber has a capacity sufficient to prevent overflow prior to such termination.
Claim 9
Dependent Claim
125 words
The combination in claim 3, and in which: said structure forming the wheel chamber includes a concave chamber wall opposedly spaced from the wheel surface and forming therewith a generally annular channel through which the wheel surface reenters the wheel chamber, the radial dimension of the channel being sufficiently small that wheel rotation exerts upon liquid in the channel a viscous drag in the direction of wheel rotation and thereby produces in the wheel chamber a superatmospheric pressure that increases with the circumferential length of channel that is filled with liquid; and said pressure head in the supply chamber is insufficient to overcome said superatmospheric pressure when the channel is filled with liquid; whereby liquid supply to the wheel chamber is terminated prior to overflow.
Claim 10
Dependent Claim
165 words
An applicator for a viscous liquid, comprising in combination: an applicator wheel assembly mounted for rotation in a forward direction with respect to an axis and including a generally cylindrical metering surface and circumferentially continuous surface of revolution means; structure forming a wheel chamber that is partially bounded by limited sectors of said metering surface and of said surface of revolution means, said structure including a face fittingly and slidingly engaging another sector of said surface of revolution means; a supply chamber for containing liquid at a pressure head sufficient to move liquid to the wheel chamber; a doctor device for metering the liquid carried by the metering surface as it leaves the chamber; passage means communicating at one end with the supply chamber and opening at the other end through a port in said face; and at least one recess in the wheel assembly opening through said surface of revolution means and positioned to communicate alternately with said port and with said wheel chamber.
Claim 11
Dependent Claim
165 words
An applicator for a viscous liquid, comprising in combination: an applicator wheel assembly mounted for rotation in a forward direction with respect to an axis and including a generally cylindrical metering surface and circumferentially continuous surface of revolution means; structure forming a wheel chamber that is partially bounded by limited sectors of said metering surface and of said surface of revolution means, said structure including a face fittingly and slidingly engaging another sector of said surface of revolution means; a supply chamber for containing liquid at a pressure head sufficient to move liquid to the wheel chamber; a doctor device for metering the liquid carried by the metering surface as it leaves the chamber; passage means communicating at one end with the supply chamber and opening at the other end through a port in said face; and at least one recess in the wheel assembly opening through said surface of revolution means and positioned to communicate alternately with said port and with said wheel chamber.
Claim 12
Dependent Claim
25 words
An applicator as defined in claim 8, and in which said recess is provided with resiliently compressible structure responsive to pressure variations in the recess.
Claim 13
Dependent Claim
33 words
An applicator as defined in claim 8, and in which said mechanism is arranged for admitting air to said recess to provide therein resiliently compressible structure responsive to pressure variations in the recess.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |