(12) United States Patent
`Buss
`
`I 1111111111111111 11111 lllll lllll lllll 111111111111111 111111111111111 11111111
`US006793872Bl
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`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,793,872 Bl
`Sep.21,2004
`
`(54) METHOD FOR MAKING CARGO LINERS
`AND MATS WITH CHANNEL EDGE
`
`(75)
`
`Inventor: Kenton A. Buss, Oxford, KS (US)
`
`(73) Assignee: Winfield Consumer Products, Inc.,
`Winfield, KS (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 152 days.
`
`(21) Appl. No.: 09/595,769
`
`(22)
`
`Filed:
`
`Jun. 16, 2000
`
`(51)
`(52)
`
`(58)
`
`(56)
`
`Int. Cl.7 . ... ... .. ... ... ... ... .. ... ... ... ... ... .. ... ... .. B29C 51/10
`U.S. Cl. ....................... 264/554; 264/138; 264/544;
`264/DIG. 78; 425/387.1; 425/388
`Field of Search ................................. 264/554, 138,
`264/163, 544, DIG. 78; 475/387.1, 388
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`5/1937 Farnham
`2,081,740 A
`3,161,915 A * 12/1964 Thiel ....................... 425/305.1
`3,190,946 A * 6/1965 Keyes ........................ 264/548
`3,337,664 A * 8/1967 Lyon ........................... 264/89
`3,402,232 A
`9/1968 De Rusha
`3,640,666 A
`2/1972 Jope et al.
`3,805,657 A * 4/1974 Simpson .................. 83/522.24
`3,827,130 A
`8/1974 Baumann
`
`5/1976
`4/1978
`3/1981
`5/1987
`11/1987
`12/1990
`* 5/1994
`10/1994
`6/1998
`6/1998
`8/1998
`8/1998
`1/2000
`
`Valyi .......................... 264/513
`Thiel et al. .............. 425/326.1
`Sabha
`Kulis
`Taylor, Jr. et al.
`Kurita et al.
`Wendt ........................ 425/299
`Batlle
`......... 425/387.1
`Rhoades et al.
`Irwin et al. .............. 425/387.1
`Giovannone et al.
`Freek et al.
`................ 264/554
`Shimono .................... 229/400
`
`Snider,
`
`3,954,923 A *
`4,086,045 A *
`4,256,690 A
`4,664,865 A
`4,704,237 A
`4,979,283 A
`5,314,324 A
`5,358,214 A
`5,759,591 A *
`5,773,540 A *
`5,795,535 A
`5,798,079 A *
`6,010,062 A *
`* cited by examiner
`Primary Examiner-Edmund H. Lee
`(74) Attorney,
`Agent,
`or
`Firm-Fellers,
`Blankenship, Bailey & Tippens, P.C.
`ABSTRACT
`
`(57)
`
`A method for making a cargo liner or a floor mat using a
`plastic molding process wherein a male mold includes a
`steel rule about its perimeter or a female mold includes a
`groove about its perimeter creating a ridge in the molded
`article to allow trimming of surplus material from the article
`along the ridge such that the dimensions of the finished
`article are determined by the ridge. In a preferred
`embodiment, an article is molded in a thermoforming
`process, the article thus produced includes a channel edge
`which enhances the appearance of the finished article and
`improves its structural integrity.
`
`6 Claims, 3 Drawing Sheets
`
`EX1012
`Yita v. MacNeil
`IPR2020-01139
`
`

`

`U.S. Patent
`U.S. Patent
`
`Sep.21,2004
`Sep. 21, 2004
`
`Sheet 1 of 3
`Sheet 1 of 3
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`U.S. Patent
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`Sep. 21, 2004
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`Sheet 2 of 3
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`US 6,793,872 Bl
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`Fig.2
`( PRIOR ART)
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`U.S. Patent
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`Sep.21,2004
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`1
`METHOD FOR MAKING CARGO LINERS
`AND MATS WITH CHANNEL EDGE
`
`US 6,793,872 Bl
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`This invention relates generally to a method for making
`cargo liners and floor mats for vehicles. More particularly,
`but not by way of limitation, the present invention relates to
`a thermoforming process for producing cargo liners or floor 10
`mats for vehicles which include a channel edge about at least
`a portion of the perimeter of the liners or mats.
`2. Background
`Cargo liners for pickup trucks, SUVs, vans, and even
`automobile trunks are well known in the art, as are floor mats
`for all types of vehicles. A common method for manufac(cid:173)
`turing such devices is a plastic thermoforming process, in
`particular vacuum or pressure forming.
`Vacuum forming and pressure forming are well known in
`the art. Generally, to vacuum form a plastic article, a mold
`is produced, either as a male likeness of the article over
`which material will be drawn, or a female likeness of the
`article into which material will be drawn. The mold is
`typically drilled with small passageways through which air 25
`may pass from the molding surfaces to the backside of the
`mold. A sheet of plastic is then heated until it becomes
`extremely pliable. The heated plastic is then placed adjacent
`the mold and vacuum is applied to the backside of the mold.
`Air passes through the passageways to create low pressure 30
`at the surface of the mold, thereby drawing the heated plastic
`tight against the mold so that the plastic takes on the shape
`of the mold. The plastic is then cooled and the molded sheet
`is lifted off the mold. Alternatively, in some cases, com(cid:173)
`pressed air is applied to the backside of the mold so that the 35
`molded plastic is blown off of the mold. In a final step,
`surplus material is trimmed from the edge of the molded
`article, typically with a router.
`Pressure forming is performed in much the same manner
`except, compressed air is applied to the heated sheet to press 40
`it onto the mold. In a sense, this is the same as the vacuum
`operation in that relatively high pressure air is on the outside
`of the plastic sheet and relatively low pressure air is on the
`mold side of the plastic sheet.
`In either operation, water or forced air may be used to
`expedite cooling of the molded article.
`While other methods are applicable to forming cargo
`liners and floor mats, thermoforming of sheet materials has
`proven to provide a cost effective method of producing
`finished product of consistent quality. However, a limitation 50
`of thermoforming arises in the subsequent trimming opera(cid:173)
`tion to remove surplus material from the perimeter of the
`article. A trimming guide may be used to guide the router
`operator in trimming the article. While a guide may work
`quite well when all of the trimming occurs in a single plane, 55
`the guide may become quite complex when trimming com(cid:173)
`plex articles. Furthermore, the trimming operation may
`introduce some variability into the dimensions of the fin(cid:173)
`ished article and it is often difficult to produce a straight edge
`of consistent width.
`Articles formed of relatively soft material may be hand
`trimmed using a knife. Unfortunately, hand trimming will
`often leave the trimmed edge of part irregular and the
`consistency of the operation is dependent on the skill of the
`individual. In addition, hand trimming places relatively large 65
`stresses on the wrists of the individual performing the
`operation.
`
`5
`
`15
`
`20
`
`2
`Therefore it can be seen that there is a need for a method
`for making cargo liners and floor mats using a thermoform(cid:173)
`ing process which facilitates trimming of the molded part in
`a secondary operation.
`It is thus an object of the present invention to provide a
`method for thermoforming a cargo liner or floor mat wherein
`a channel edge is formed during the molding process to
`facilitate cutting and to provide an improved article.
`
`SUMMARY OF THE INVENTION
`
`The present invention provides a method for making
`cargo liners and floor mats using a plastic molding process.
`In the inventive process, a steel rule or a groove is incor(cid:173)
`porated into the mold to produce a ridge in the molded part
`to facilitate subsequent trimming.
`In a preferred embodiment, when heated plastic is drawn
`over a steel rule during a thermoforming process, a channel
`edge is formed in the plastic article about its perimeter.
`During a subsequent trimming operation to remove surplus
`material, trimming is performed on the ridge created by the
`steel rule thereby reducing variations in the edge which
`result from the trimming operation to produce an edge which
`enhances the appearance of the finished article with less
`dependance on operator skill during the trimming operation.
`An article produced by the inventive process will include a
`channel edge about at least a portion of its perimeter.
`While the inventive process is applicable to virtually any
`molding operation which requires a subsequent trimming
`operation, it is especially well suited to thermoforming of
`plastic sheet materials. By way of example and not
`limitation, such processes include vacuum forming, pressure
`forming, and rotational molding. Furthermore, such forming
`may involve either a male mold or a female mold.
`Further objects, features, and advantages of the present
`invention will be apparent to those skilled in the art upon
`examining the accompanying drawings and upon reading the
`following description of the preferred embodiments.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 provides an elevational view of a cargo liner made
`with the inventive method in its general environment.
`FIG. 2 provides a cutaway view of a prior art mold with
`45 a sheet of plastic material drawn over the mold.
`FIG. 3 provides a cutaway view of the an inventive male
`mold incorporating a steel rule.
`FIG. 4 provides a cutaway detail of an inventive male
`mold incorporating a steel rule.
`FIG. 5 provides a cutaway view of a cargo liner made with
`the inventive method prior to the trimming operation.
`FIG. 6 provides a cutaway view of a cargo liner made with
`the inventive method after the trimming operation.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`Before explaining the present invention in detail, it is
`important to understand that the invention is not limited in
`60 its application to the details of the construction illustrated
`and the steps described herein. The invention is capable of
`other embodiments and of being practiced or carried out in
`a variety of ways. It is to be understood that the phraseology
`and terminology employed herein is for the purpose of
`description and not of limitation.
`The inventive method preferably relates generally to the
`thermoforming of plastic liners. By way of example and not
`
`

`

`US 6,793,872 Bl
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`3
`limitation, the inventive method is ideally suited for the
`production of cargo liners for trucks, sport utility vehicles,
`automobile trunks, boats, etc. and for floor mats for vehicles
`in general. The inventive thermoforming method produces a
`ridge in the molded article which greatly facilitates
`trimming, enhances the appearance of the finished article,
`and improves the structural integrity of the finished article.
`Thermoforming processes include vacuum forming, pres(cid:173)
`sure forming, rotational molding, and the like. Thermoform(cid:173)
`ing processes may utilize either a male mold wherein the
`plastic material is drawn over the mold, a female mold
`wherein the material is drawn into the mold, or a combina(cid:173)
`tion of both male and female details incorporated into a
`single mold. The inventive method is applicable to all such
`thermoforming processes. For the sake of simplicity, the
`preferred embodiment of the inventive method will be
`discussed in reference to a vacuum forming process however
`the invention is not so limited.
`Referring first to FIGS. 3 and 4, a preferred embodiment
`of a mold for use with the inventive method includes a steel
`rule 12 incorporated into male mold 14, rule 12 being spaced
`substantially an equal distance 16 from the perimeter 26 of
`article 32 at all points along its path. The mold 14 is drilled
`with small passageways (not shown) such that air may pass
`freely from the molding surfaces 20 to the backside 22 of the
`mold. When vacuum is applied to the backside of mold 14,
`low pressure will be present at the molding surfaces 20. A
`sheet of thermoplastic material 24 is heated until the sheet 24
`becomes extremely pliable. Sheet 24 is then placed against
`the surface of mold 14 and vacuum is applied to the backside
`22 of mold 14, drawing sheet 24 tightly over mold 14. Steel
`rule 12 creates a ridge in sheet 14 which follows perimeter
`26 of article 32. Sheet 24 is preferably cooled with water or
`forced air to accelerate the cooling process. Once cooled,
`sheet 24 is lifted from mold 14, or alternatively compressed
`air may be applied to the backside 22 of mold 14 to remove
`sheet 24 from mold 14. The shape impressed upon sheet 24
`by mold 14 will remain upon removal of sheet 24 from mold
`14. With the exception of the steel rule 12, the process
`described above is a vacuum forming process which is
`known in the art.
`A prior art method of thermoforming is depicted in FIG.
`2. Typically with a thermoformed article 102, surplus mate(cid:173)
`rial 100 must be trimmed from around the molded article
`102. A router is often used to perform this operation
`however, a guide or template is often used to improve the
`dimensional consistency and quality of such articles. Rela(cid:173)
`tively soft thermoplastic materials may be hand trimmed
`with a knife to separate the molded part from the surplus
`material. However, hand trimming results in dimensional
`inconsistencies along the edges of these articles.
`Trimming of articles formed by the inventive method
`requires no such guide or template. Instead, a router or saw
`is located a predetermined distance above a table top such
`that any material above a certain height will be removed and 55
`any material below the height will remain untouched. The
`height preferably being lower than the height of the ridge 30
`(FIG. 5) created in sheet 14 by steel rule 12. Thus, when
`ridge 30 is passed under the router, trimming of the article
`will thus occur along ridge 30 as shown by the drawn line 60
`in FIG. 6. It will be obvious to those skilled in the art that
`the dimensions of article 32 (FIG. 6) will be determined by
`the position of ridge 30 independent of the skill of the
`operator performing the trimming and, furthermore, that no
`guides or templates are required to perform such trimming. 65
`Relatively soft materials may be easily hand trimmed with
`a knife. The groove which is inherently formed on the side
`
`4
`opposite the ridge, acts as a guide for the knife during a hand
`trimming operation. It will be apparent to those skilled in the
`art that the material at the bottom of the groove will be
`thinner than the original sheet of material thus reducing
`5 stresses placed on the wrists of the individual performing the
`hand trimming operation. These features facilitate faster,
`more accurate trimming resulting in increased production
`and lower scrap rates due to improper trimming.
`Once trimmed, article 32 includes a substantially vertical
`10 peripheral wall portion 31, a transverse outer edge portion
`33 and a nub 35, thus forming a channel edge 34, the width
`of which corresponds to the distance 16 between mold 14
`and steel rule 12. Channel edge 34 provides an enhanced
`appearance to article 32 over articles produced by prior art
`15 methods. In addition, channel edge 34 improves the struc(cid:173)
`tural integrity of article 32.
`In another embodiment, a groove is provided about the
`perimeter of a female mold. The groove is provided with
`passageways periodically about its path to ensure that the
`20 sheet will be drawn into the groove during the forming
`operation. The forming operation for a female mold is
`similar to the forming operation with a male mold 14
`discussed hereinbefore. The sheet is first heated, placed over
`the opening of the cavity, vacuum is applied to the backside
`25 of the mold thereby tightly drawing the sheet into the cavity.
`After cooling, the sheet is removed from the cavity or,
`alternatively, compressed air may be applied to the backside
`of the cavity to separate the sheet from the mold. Trimming
`of an article molded in a female mold is identical to the
`30 trimming of article 24 formed over male mold 14.
`A cargo liner 110 produced by the inventive method is
`shown in FIG. 1. Cargo liner 110 includes a channel edge
`(not shown) which is formed as article of the inventive
`method. Preferably, the channel edge is of substantially
`35 uniform width giving cargo liner 110 an enhanced appear(cid:173)
`ance as compared to liners produced by prior art methods.
`Although the inventive method is discussed herein and
`described in reference to the production of a cargo liner, it
`40 is equally applicable to the production of floor mats for
`vehicles or any other type of formed liner.
`As will be apparent to those skilled in the art, sheet goods
`for thermoforming are available in a variety of materials and
`thicknesses. The inventive method is applicable to all such
`45 sheet goods.
`Thus, the present invention is well adapted to carry out the
`objects and attain the ends and advantages mentioned above
`as well as those inherent therein. While presently preferred
`embodiments have been described for purposes of this
`50 disclosure, numerous changes and modifications will be
`apparent to those skilled in the art. Such changes and
`modifications are encompassed within the spirit of this
`invention as defined by the appended claims.
`What is claimed is:
`1. A method for making a molded vehicle liner, wherein
`said liner includes a substantially vertical peripheral wall
`portion and a transverse outer edge portion and said vehicle
`liner is either a cargo liner or floor mat comprising:
`( a) heating a sheet of plastic material having a mold side
`and an exposed side to a first temperature, said first
`temperature being consistent with forming said sheet of
`plastic material in a thermoforming process;
`(b) placing said mold side of said sheet of plastic material
`over a mold, said mold having a first surface for
`forming said substantially vertical peripheral wall
`portion, a second surface substantially perpendicular to
`said first surface, and a steel rule placed along said
`
`

`

`US 6,793,872 Bl
`
`5
`second surface at a predetermined distance from said
`first surface for forming said outer edge portion;
`(c) applying a vacuum to said mold or compressed gas to
`said exposed side of said sheet of plastic material such
`that air pressure on said mold side is less than the air
`pressure on said exposed side;
`( d) forming a ridge over said steel rule along at least a part
`of said outer edge portion, said ridge being of a
`substantially uniform height;
`( e) cooling said sheet of plastic material to a second
`temperature, said second temperature being consistent
`with said sheet of plastic material retaining its molded
`shape;
`(f) releasing said vacuum from said mold or said com- 15
`pressed gas from said exposed side;
`(g) removing said sheet of plastic material from said
`mold; and
`(h) after removing said sheet of plastic material from said
`mold, cutting said sheet of plastic material along said 20
`ridge to release said liner from said sheet.
`2. The method according to claim 1, wherein said steel
`rule encompasses the entire periphery of the mold and step
`( d) further includes forming said ridge about the entirety of
`said outer edge portion at a substantially coequal distance 25
`from said wall portion.
`3. The method according to claim 2, wherein there is
`provided after step (h) a channel edge of a substantially
`uniform width about the periphery of said liner.
`4. A method for making a molded vehicle liner, wherein 30
`said liner includes an outer edge portion and said vehicle
`liner is either a cargo liner or floor mat comprising:
`(a) molding a liner having an outer edge portion from a
`sheet of plastic material in a mold having a steel rule
`encompassing the periphery of said mold, said outer 35
`edge portion having a ridge along at least a part of said
`outer edge portion, said ridge being formed over said
`steel rule and said ridge being of a substantially uni(cid:173)
`form height;
`(b) removing said liner from said mold; and
`(c) after removing said liner from said mold, cutting said
`liner along said ridge to release said liner from said
`
`40
`
`10
`
`6
`sheet of plastic material such that said ridge defines the
`outer edge of said liner.
`5. The method according to claim 4, wherein step (a)
`further includes molding said ridge about the entirety of said
`5 outer edge portion.
`6. A method for making a molded vehicle liner from a
`sheet of thermoforming plastic, wherein said liner includes
`a continuous outer edge portion and said vehicle liner is
`either a cargo liner or floor mat comprising:
`( a) heating a sheet of plastic material having a mold side
`and an exposed side to a first temperature, said first
`temperature being consistent with forming said sheet of
`thermoforming plastic in a thermoforming process;
`(b) placing said mold side of said sheet of thermoforming
`plastic over a mold, said mold having a steel rule of
`substantially uniform height positioned about the
`periphery of said mold;
`(c) applying a vacuum to said mold or compressed gas to
`said exposed side of said sheet of thermoforming
`plastic such that air pressure on said mold side is less
`than the air pressure on said exposed side;
`( d) forming a ridge over said steel rule along the entirety
`of said outer edge portion such that said thermoforming
`plastic is thinner than the original thickness of the sheet
`of thermoforming plastic along said ridge to facilitate a
`trimming operation;
`( e) cooling said sheet of plastic material to a second
`temperature, said second temperature being consistent
`with said sheet of thermoforming plastic retaining its
`molded shape;
`(f) releasing said vacuum from said mold or said com(cid:173)
`pressed gas from said exposed side;
`(g) removing said sheet of thermoforming plastic from
`said mold; and
`(h) trimming said sheet of thermoforming plastic along
`said ridge where said thermoforming plastic is thinner
`to release said liner from said sheet.
`
`* * * * *
`
`