US3591767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiant shrink tunnel
Assignee: Individual
•
Filing: 1969-06-23
•
Granted: 1971-07-06
•
Expires: 1989-06-23
Abstract
Abstract An open-ended tunnel-shaped heating chamber for shrink wrapping of large quantities of merchandise in pallet loads, the chamber being open at each end for erection on a conveyor system without the use of doors, and having electrical radiant heating units arranged in three separate zones consisting of forward, rear and intermediate zones, along the tunnel, the forward and rear zones being arranged and directed to progressively heat and shrink different portions of the shrink film draped around the merchandise on the loaded pallet and the intermediate zone being arranged to heat the film-draped around the lower region of the pallet and shrink the same around and underneath the pallet, the heating units being provided with parabolic reflectors to focus and direct the heat in narrow intense bands so as to procure progressive heating of small areas of the films, and the tunnel being provided with heat reflective baffle means to trap any stray radiant heat which may otherwise escape from the tunnel through its open ends, and the heating being provided with separate zone controls whereby the operator can vary the heat applied by each of the zones, thereby enabling the construction of a shrink tunnel without doors for incorporation in a continuous flow production line.
Inventors
- 👤 David Jeffrey Mudie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:29
CPC Classifications
B; B65; B65B; B65B53/00; B65B53/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
340 words
Radiant heat shrink tunnel apparatus for use in association with a continuous conveyor system in the shrink wrapping of bulk merchandise on pallets and the like in shrinkable plastic film material and comprising: an open ended tunnel-shaped heating chamber having a top, side walls and front and rear end walls, and openings formed in said front and rear end walls for use in conjunction with a conveyor system adapted to move unit loads of merchandise for packaging through said tunnel-shaped chamber from said rear end wall to said front end wall; A front group of radiant heating units arranged in elongated bands and located within said chamber towards said front end wall thereof said units incorporating radiant heat focusing means arranged and oriented to focus and direct a major proportion of radiant heat therefrom rearwardly into the interior of said chamber for heating the front, sides and top of shrink film on a loaded pallet as the same advances into the chamber; a rear groUp of radiant heating units arranged in elongated bands and located in said chamber spaced apart from said front group of heating units, and arranged towards said rear end of said chamber, said units incorporating radiant heat focusing means arranged and oriented to focus and direct a major proportion of radiant heat therefrom forwardly into said chamber to heat the sides, top, and rear of the film on a loaded pallet moving therethrough; inwardly directed radiant heat mirror baffle members mounted adjacent to said front and rear groups of heating units, and extending substantially therebetween and angled to capture at least some radiant heat scattered therefrom and redirect the same into said chamber; a lower group of intermediate heating units arranged on each side of said chamber, and located more or less along the plane of said conveyor, in order to heat the lower side portions of said film as said pallet advances through said chamber, and, heating control means for at least two of said groups of heating units for controlling the heat output thereof.
Claim 2
Dependent Claim
340 words
Radiant heat shrink tunnel apparatus for use in association with a continuous conveyor system in the shrink wrapping of bulk merchandise on pallets and the like in shrinkable plastic film material and comprising: an open ended tunnel-shaped heating chamber having a top, side walls and front and rear end walls, and openings formed in said front and rear end walls for use in conjunction with a conveyor system adapted to move unit loads of merchandise for packaging through said tunnel-shaped chamber from said rear end wall to said front end wall; A front group of radiant heating units arranged in elongated bands and located within said chamber towards said front end wall thereof said units incorporating radiant heat focusing means arranged and oriented to focus and direct a major proportion of radiant heat therefrom rearwardly into the interior of said chamber for heating the front, sides and top of shrink film on a loaded pallet as the same advances into the chamber; a rear groUp of radiant heating units arranged in elongated bands and located in said chamber spaced apart from said front group of heating units, and arranged towards said rear end of said chamber, said units incorporating radiant heat focusing means arranged and oriented to focus and direct a major proportion of radiant heat therefrom forwardly into said chamber to heat the sides, top, and rear of the film on a loaded pallet moving therethrough; inwardly directed radiant heat mirror baffle members mounted adjacent to said front and rear groups of heating units, and extending substantially therebetween and angled to capture at least some radiant heat scattered therefrom and redirect the same into said chamber; a lower group of intermediate heating units arranged on each side of said chamber, and located more or less along the plane of said conveyor, in order to heat the lower side portions of said film as said pallet advances through said chamber, and, heating control means for at least two of said groups of heating units for controlling the heat output thereof.
Claim 3
Dependent Claim
105 words
Radiant heat shrink tunnel apparatus as claimed in claim 1, wherein said front group of heating units is arranged partly on the ceiling of said chamber, and partly on each side thereof, and wherein the said rear group of heating units is similarly arranged, partly on the ceiling of said chamber and partly on each side thereof, said front and rear group of heating units being focused and oriented to establish beams of relatively narrow elongated bands of radiant heat having a more or less rectangular shape in cross section, said beams being angled and directed more or less towards the center of said chamber.
Claim 4
Dependent Claim
42 words
Radiant heat shrink tunnel apparatus as claimed in claim 1, including flexible draft excluding flap members attached to said front and rear ends respectively along their upper edges, and heat reflective means on the inwardly directed surfaces of said draft excluding members.
Claim 5
Dependent Claim
36 words
Radiant heat shrink tunnel apparatus as claimed in claim 1, wherein each of the heating elements in said groups of elements in said groups of elements comprises an elongated radiant heat source, and a parabolic reflector.
Claim 6
Dependent Claim
83 words
Radiant heat shrink tunnel apparatus as claimed in claim 1, wherein said lower group of heating units include at least two horizontal heating units arranged lengthwise in the lower portion of said heating chamber on either side of said conveyor system and substantially in the plane thereof, said horizontal heating units being located so as to begin heating of said lower side portions of said film just prior to direct application of radiant heat by said front and rear groups of heating units.
Claim 7
Dependent Claim
76 words
Radiant heat shrink tunnel apparatus as claimed in claim 1, wherein said front and rear groups of heating units each include at least two long vertical heating units arranged one on each side of said chamber, and at least two horizontal heating units arranged end to end and supported in the top of said chamber, spaced apart a predetermined distance whereby to direct heat downwardly onto the upper corners of the film on said loaded pallet.
Claim 8
Dependent Claim
54 words
Radiant heat shrink tunnel apparatus as claimed in claim 1 wherein said lower group of heating units include at least two short vertical heating units arranged on either side of said chamber more or less equidistant between said front and rear walls thereof, focused and oriented to direct heat substantially directly across said chamber.
References Cited (Backward Citations)
US2360257A
Cited
US2349300A
Cited
US2529704A
Cited
US2917616A
Cited
US3032638A
Cited
US3171945A
Cited
US3312811A
Cited
US3357153A
Cited
US3508375A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |