Thermostatic Heat Wheel

Abstract

A heat transfer wheel including a label transfer pad to carry address-bearing labels from a label pick-up station to the point of application where the addresses are transferred to an article through the use of heat, heating means in said label transfer pad, said transfer pad being thermally insulated from the rest of the wheel to facilitate heat retention and distribution; vacuum passage means leading to the label bearing surface of the label transfer pad to enable labels to be temporarily attached thereto; and thermostatic control means in heat exchange relation with said label transfer pad for regulating operation of said heating means in response to temperature conditions of said pad so as to maintain said transfer pad at a uniform temperature condition.

Description

This invention relates to article addressing machines, and more particularly, to an improved heat transfer wheel for use with article addressing machines.

Certain automatic addressing machines for addressing or labeling articles, for example envelopes, utilize a rotatable, heated transfer wheel to carry the address-bearing item, normally referred to as a label, into physical contact with the article being addressed. The addressing machine incorporates suitable article transport means to bring the articles, one at a time, into operative position with the label transfer wheel.

In some applications, the labels themselves are physically attached to the articles and in this type of application, the labels carry a heat activated adhesive on their underside to enable the labels to be secured to the articles. During the relatively short interval while the label is borne by the label transfer wheel from the label supply point to the point where the label is transferred to the article, the transfer wheel must heat the label sufficiently to activate the adhesive.

In other applications, the address information may be formed on carbon paper-type labels. Here the physical contact between the label and article in the presence of heat causes the information on the label to be transferred to the article. The used labels are thereafter removed from the transfer wheel and stored for subsequent use or simply thrown away. As in the case of the adhesive bearing labels, the transfer wheel is relied upon as the source of heat.

In effecting the aforedescribed transfer of label or label information to articles, the heat input to the label supporting pad of the transfer wheel, which in turn is transmitted to the label itself, is critical. If too little heat is provided, transfer of the label or the label information may be incomplete. On the other hand, too much heat may result in incomplete transfer of the label or label information or damage to the label.

It is an object of the present invention to provide a new and improved heat transfer wheel for article addressing machines.

It is a further object of the present invention to provide controlled heat at the label bearing pad of a heat transfer wheel.

It is a further object of the invention to provide an improved label transfer wheel having multiple heating elements embedded in the label carrying pad thereof, with thermostatic means for controlling at least one of the heating elements in response to temperature conditions of the pad.

It is a further object of the invention to provide, in a label transfer wheel having a thermally insulated label support pad, thermostatic control means for maintaining pre-determined temperature conditions on the external surface of the label support pad.

This invention relates to a heat transfer wheel for bringing labels having address information thereon into transfer contact with articles to be labeled, the combination of, a base member adapted for rotatably mounting; at least one label transfer pad having a surface area adapted to support a label thereon; heating means for heating the pad surface area; means for mounting the pad on the base member in insulating relation thereto whereby to minimize loss of heat from the label transfer pad through the base member; means to permit vacuum to be applied to at least a portion of the pad surface area so as to temporarily hold a label on the pad surface area and enable the base member to transport the label into contact with an article to be labeled; and control means for regulating operation of the heating means whereby to maintain the label transfer pad within a pre-determined temperature range.

Other objects and features of the invention will be apparent from the following description and drawings in which:

FIG. 1 is a side elevational view of an addressing machine with portions broken away to show internal mechanisms;

FIG. 2 is an exploded view of the improved label transfer wheel of the present invention;

FIG. 3 is a vertical sectional view of the label transfer wheel shown in FIGS. 1 and 2;

FIG. 4 is a horizontal sectional view of the label transfer wheel taken along lines 4--4 of FIG. 1;

FIG. 5 is a wiring diagram for the label transfer wheel shown in FIGS. 1 and 2; and

FIG. 6 is an alternate wiring diagram for the label transfer wheel shown in FIGS. 1 and 2.

Referring to FIG. 1 there is shown an automatic addressing machine 5 of the type adapted to use the label applicator or transfer wheel 10 of the present invention. Addressing machine 5 is encased in housing 11, parts of which have been removed as required to show internal constructions. Addressing machine 5 includes, on the left side thereof, as viewed in FIG. 1, a magazine 12 for the reception of articles to be labeled. The walls of the magazine are adjustable for receiving stacks of materials of varying sizes. Suitable conveying mechanisms (not shown) are employed to feed the bottom-most article in magazine 12 forward into association with article transport belt 14 which carries the article into operative position with transfer wheel 10. Transport belt 14 is supported on rollers 16 and 18, at least one of which is driven by a suitable source of power (not shown).

Labels to be used for addressing are supplied from label preparation station 21, preparation station 21 serving to cut, trim and feed the labels sequentially to the label transfer wheel 10 for transfer of the label itself or of the address information only to the article being carried therepast by transport belt 14. As will appear, transfer wheel 10 picks up through vacuum holddown means individual labels from pick-up station 23 and carries the individual labels through an arc of approximately 180.degree. into physical contact with the article moving therebelow on transport belt 14.

During the interval while the label is carried on transfer wheel 10, heat from label transfer wheel 10 is relied upon to partially melt, soften or tackify either the carbonized address information on the label where the label is a heat transfer type label or the heat activated adhesive on the bottom of the label where the label is an adhesive label. Where heat transfer type labels are used, the vacuum control valving (not shown) is arranged so that the label itself is retained on transfer wheel 10 past the point 27 where label information is transferred to the article and until the used label comes opposite vacuum pick-off wheel 31. At this point, the vacuum of pick-up wheel 31 removes the used label from transfer wheel 10 and onto vacuum pick-off wheel 31 for disposition in used label storage trough 34. Where addressing machine 5 is operated with adhesive type labels which are physically transferred to the article by applicator wheel 10, the vacuum pick-off wheel 31 and trough 34 are not used and may be eliminated.

Referring now to FIGS. 2, 3 and 4 of the drawings, label transfer wheel 10 comprises a base member or block 20 and a vacuum or heat pad 22. As will appear, one side 24 of block 20 cooperates with the stationary vacuum distributing block 25 to couple wheel 10 with the vacuum source while the opposite or second side 26 of block 20 cooperates with slip rings 28 to couple heating elements 30 with the source of electrical power.

Block 20 is suitably apertured at 32 for mounting on drive shaft 33 of addressing machine 5. Vacuum passages 35 are provided in block 20, passages 35 leading from side 24 of block 20 to the heat pad support surface 38. The opposed or second side 26 of block 20 has an arcuate recess 40 for holding the electrical wiring leading to heating elements 30. The recess 40 is best seen in FIG. 3.

Heat pad 22 is constructed of a thermally conductive rigid material and is provided with vacuum grooves 42 over the label supporting portion of its periphery. Primary vacuum passages 43 in pad 22 have branch passages 44 communicating with vacuum grooves 42, the construction being such that on coupling of primary vacuum passages 43 with a source of vacuum, a partial vacuum is created along the periphery 45 of pad 22 to retain the label on the periphery of heat pad 22. Apertures 50, 52, which are substantially parallel with the axis or rotation of label transfer wheel 10, are provided for the reception of heating elements 30 and thermostat 54 respectively as will appear more fully hereinafter.

An insulated manifold plate 56 is disposed between applicator wheel base 20 and heating pad 22, plate 56 being rigidly secured between heating pad 22 and block 20 by suitable means. A network of vacuum passages 62 through manifold plate 56 communicates vacuum passages 35 in block 22 with primary vacuum passages 43 in heating pad 22. Suitable thermal insulating washers 64 are provided between manifold plate 56 and block 20 to assure effective thermal isolation of heating pad 22 from block 20.

Suitable valve means (not shown) are provided in manifold plate 56 to permit the vacuum to pad 22 to be controlled in accordance with operating conditions.

Heat is supplied to the vacuum pad 22 by heating elements 30 which fit in the apertures 50 in pad 22. As best shown in FIG. 3, the heating rods 30 are arranged proximate the label bearing surface 45 of vacuum pad 22, elements 30 being located so that the surface 45 is substantially uniformly heated to assure complete and even transfer of the address information to the articles.

Electrical power is supplied to the heating elements 30 through suitable leads 63 which are held within the recess 40 of block 20. Recess 40 is closed as by insulated plate 65. Slip rings 28 are supported on plate 64 by screws 67 which serve to electrically connect rings 28 with leads 64 of heating elements 30. Support shaft 33 is journaled in addressing machine frame part 71 as by ball bearing 69.

The transfer wheel 10 is positioned on shaft 33 such that slip rings 28 on face 26 of wheel 10 contact brushes 70 on machine part 71. Brushes 70 are connected with a suitable source of electrical energy as will appear.

The stationary vacuum distributing block 25 has suitable arcuate vacuum distributing grooves 73 in the inside face 74 thereof. Suitable passage means (not shown) communicate grooves 73 via hose type coupling 78 with a suitable source of vacuum. The relative rotation developed between transfer wheel 10 and distributing block 25 on rotation of wheel 10 selectively communicates vacuum grooves 42 with the source of vacuum to enable wheel 10 to pick up and carry the label from label preparation station 21 into physical contact with the articles carried therepast on transport belt 14 where the label is released. It is understood that where the address information only is transferred to the article, the design of grooves 73 is altered to assure that the transfer wheel 10 retains the used label on vacuum pad 22 thereof until the used label is removed by pick-off wheel 31 for storage in trough 34.

To control heating elements 30 and maintain desired temperature conditions at the transfer wheel pad 22, a suitable temperature responsive control element or thermostat 54 is disposed in heat exchange relation with vacuum pad 22. In the exemplary showing of the drawings, thermostat 54 comprises a tubular element carried within aperture 52 in pad 22, aperture 52 being located generally intermediate the multiple heating elements 30. To provide visible indication to the user of temperature conditions of pad 22, a suitable signal light 75 is preferably provided on side 24 of base 20 of transfer wheel 10.

Referring particularly to FIG. 5, heating elements 30 are connected through slip rings 28 and brushes 70, thermostat 54, and a suitable off-on switch 76 across a suitable source of electrical energy as represented by leads L.sub.1, L.sub.2. To enable signal light 75 to reflect the safe operating condition of transfer wheel 10, light 75 is connected in parallel with thermostat 54. By this arrangement, light 75 is operative when thermostat 54 is open and current to heating elements interrupted as when heat pad 22 is at or above the predetermined temperature response of thermostat 54. Where thermostat 54 closes to complete an energizing circuit to heating elements 30 however, the current drain is sufficient to render light 75 inoperative and indicate to the user that heat wheel 10 is below desired operating temperature.

In the embodiment shown in FIG. 6, where like numerals refer to like parts, certain of the heating element 30' are connected directly through on-off switch 76 with leads L.sub.1, L.sub.2. The remaining heating elements 30" are controlled by thermostat 54 in the manner described in connection with FIG. 5 above.

In the FIG. 6 embodiment, the continuously operating heating elements 30' serve to maintain the pad 22 of heat wheel 10 at a base or minimum temperature with the remaining heating elements 30" being cycled on and off as required in accordance with temperature conditions of heat pad 22 as sensed by thermostat 54.

While the invention has been described with reference to the structure disclosed, it is not confined to the details set forth, but is intended to cover such modifications, or changes as may come within the scope of the following claims.

Claims

I claim

1. In a heat transfer wheel for bringing labels having address information thereon into transfer contact with articles to be labeled, the combination of:

a base member adapted for rotatable mounting;

at least one label transfer pad having a surface area adapted to support a label thereon;

heating means for heating said pad surface area including at least one resistance type heater;

an energizing circuit for said heater;

means for mounting said pad on said base member in insulating relation thereto whereby to minimize loss of heat from said label transfer pad through said base member;

means to permit vacuum to be applied to at least a portion of said pad surface area so as to temporarily hold a label on said pad surface area and enable said base member to transport said label into contact with an article to be labeled, and

control means for regulating operation of said heating means whereby to maintain said label transfer pad within a predetermined temperature range,

said control means including a temperature responsive switching element in heat exchange relation with said label transfer pad and in series with said heater circuit, said switching element being adapted on a predetermined low temperature condition of said label transfer pad to close whereby to energize said heater and on a predetermined high temperature condition of said label transfer pad to open whereby to deenergize said heater; and

signal light means to visibly indicate temperature conditions of said label transfer pad, said light means being in parallel circuit relationship with said switching element such that on opening of said switching element, said light means is activated and on closure of said switching element, a bypass circuit is established effectively rendering said light means inoperative.

2. The heat transfer wheel according to claim 3 in which said control means includes a temperature responsive element in heat exchange relation with said label transfer pad.

3. In a heat transfer wheel for bringing labels having address information thereon into transfer contact with articles to be labeled, the combination of:

a base member adapted for rotatable mounting;

at least one label transfer pad having a surface area adapted to support a label thereon;

heating means for heating said pad surface area;

means for mounting said pad on said base member in insulating relation thereto whereby to minimize loss of heat from said label transfer pad through said base member;

means to permit vacuum to be applied to at least a portion of said pad surface area so as to temporarily hold a label on said pad surface area and enable said base member to transport said label into contact with an article to be labeled;

control means for regulating operation of said heating means whereby to maintain said label transfer pad within a predetermined temperature range;

said heating means comprising at least two individual heat sources and;

means for energizing one of said heat sources continuously during labeling operation of said transfer wheel,

said control means serving to operate the other of said heat sources in response to temperature conditions of said label transfer pad.

4. The heat transfer wheel according to claim 3 including

means for signaling operating temperature conditions of said label transfer pad; said control means being adapted to actuate said signaling means on deenergization of the other of said heat sources.