Reinforced refrigerator cabinet closing drawer

Information

  • Patent Grant
  • 6609774
  • Patent Number
    6,609,774
  • Date Filed
    Tuesday, January 28, 2003
    22 years ago
  • Date Issued
    Tuesday, August 26, 2003
    21 years ago
Abstract
A refrigerator with a pull out drawer has plastic cabinet and drawer liners and a closed reinforcing assembly mounted within the drawer and cabinet for supporting loads carried by the drawer. The assembly has a reinforcing brace secured within the drawer having two spaced apart wing members and a cross member connected to and extending between the wing members adjacent an inside surface of the inner liner. The assembly has a pair of telescopically extendable guide rails each mounted to one of the opposing liner side walls of the cabinet and the through the liner of the drawer to support the drawer for relative movement with the cabinet. The cabinet has a pair of reinforcing bracket members located therein each having a side reinforcing portion extending adjacent a corresponding one of the guide rails and mounted to the liner side wall by fasteners passing through the guide rails and liner side walls. The reinforcing bracket members each having a rear wall portion extending orthogonal from the respective side reinforcing portions adjacent to and in contact with the rear wall of the interior liner secured to each other to form a continuous arm to interconnect and reinforce the side reinforcing portions. The closed reinforcing assembly comprising the reinforcing brackets, the guide rails and the reinforcing brace provide a closed loop rectangular reinforcing structure for loads carried by the guide rails and drawer.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates generally to structural supports for use in refrigerator cabinets employing polyurethane foam insulation and, more particularly, to supports which may be used for supporting a pull out drawer that closes an open front of a refrigerator.




2. Description of the Prior Art




In the art of refrigerator cabinet construction, particularly where plastic inner liners are employed, it is frequently necessary to provide selective reinforcement because the plastic liner walls are not strong enough to carry shelf load even when the walls are foamed in place. For example, where shelf supports or the like are attached to the inner liner, particularly a plastic inner liner, some form of support is needed. A screw receiving aperture in the plastic is generally unsatisfactory, except where extremely light loads are involved, because insufficient area for thread engagement results and the entire load is concentrated on a very small portion of the plastic material. These factors contribute to premature undesirable deformation or cracking of the plastic sheet.




In a typical refrigerator construction, metallic plates are used generally as stiffening members where needed. In a more specific application, where a load such as a shelf is to be applied to a plastic inner liner, metallic or plastic back plates are employed.




Another type of local stiffener support is disclosed in U.S. Pat. No. 4,190,305 issued Feb. 26, 1980 and 4,107,833 issued Aug. 22, 1978 to Knight et al. These patents teach the use of a fibrous material behind the inner wall of the refrigerator cabinet to locally reinforce the cabinet. The material is compatible with polyurethane foam insulation.




Where exceptionally heavy loads must be applied to the inner liner, a separate metallic or molded plastic member may be employed which actually bridges between the inner liner and the outer case to transmit the applied interior load directly to the metal outer case. However, such members may act as a thermal conductor between the inner liner and outer wall.




The structural reinforcement is typically a localized reinforcement and does not extend beyond the localized areas to be reinforced. Hence, for heavily loaded pull out drawers utilized in bottom mount refrigerators such local structural reinforcement is not usually sufficient for a refrigerator having a plastic liner. There is a need for reinforcement beyond localized reinforcement.




SUMMARY OF THE INVENTION




The present invention relates to a refrigerator appliance having a pull out drawer or door mounted by guide rails to a refrigerator cabinet for closing an open front portion of the refrigerator cabinet. The refrigerator has a closed loop reinforcing assembly that maintains the structural integrity of the cabinet and drawer for loads carried by the guide rails. The closed reinforcing assembly includes a cabinet liner reinforcement assembly mounted within the refrigerator cabinet that co-operates with a drawer reinforcing brace assembly mounted within the refrigerator drawer.




The reinforcing bracket assembly is located within the cavity of the insulated cabinet and has side reinforcing portions extending along the liner side walls adjacent a corresponding one of the guide rails. The side reinforcing portions are mounted to both the cabinet liner side wall and the guide rails by fasteners passing through the guide rails and liner side walls. The side reinforcing portions are local reinforcement to the liner side walls adjacent the guide rails. The reinforcing bracket assembly, additionally has a rear wall arm extending orthogonal from the respective side reinforcing portions adjacent to and, preferably in contact with, an inside surface of the rear wall of the interior liner. The rear wall arm interconnects and reinforces the side reinforcing portions to structurally support the liner side walls of the liner from flexing outwardly from each other adjacent the guide rails. The interconnection of the side reinforcing portions by the rear wall arm structural liner and cabinet reinforcement beyond local reinforcement.




The reinforcing brace of the closed reinforcing assembly is secured within the drawer at least partially extending across the width of the drawer. The reinforcing brace is connected to the guide rails at end portions thereof to complete a closed reinforcing structure extending around the cabinet liner and across the drawer liner. In addition to providing local support, the closed reinforcing assembly or structure provides a box-like reinforcement able to support loads carried by the guide rails in addition to the load of the drawer.




The reinforcing bracket assembly provides local reinforcement of the liner side walls of the cabinet to support the guide rails mounted thereto. The reinforcement is further enhanced by the reinforcing bracket assembly when it is foamed in place. Additionally, the interconnection of the side reinforcing portions by the rear wall arm structurally supports the liner side walls from flexing inwardly and outwardly and prevents the transfer of stresses related to the opening of the drawer under predetermined load conditions which stresses would otherwise lead to the liner cracking.




In accordance with one aspect of the present invention, the reinforcing bracket assembly is located within the cavity of the refrigerator cabinet and has side reinforcing portions extending along the liner side walls adjacent a corresponding one of the guide rails. The side reinforcing portions are mounted to the liner side wall by fasteners passing through the guide rails and liner side walls. The side reinforcing portions having support flanges extending into and engaging the foam for providing local reinforcement to the liner side walls. The reinforcing bracket assembly has a rear wall arm extending orthogonal from the respective side reinforcing portions adjacent to and, preferably in contact with, the rear wall of the interior liner. The rear wall arm interconnects and reinforces the side reinforcing portions to structurally support the liner side walls of the liner from flexing relative to each other and to thereby prevent stresses from being transferred onto the liner from the pull out drawer when the pull out drawer carries a predetermined load into an open position.




The reinforcing brace of the refrigerator pull out drawer provides localized reinforcement to the drawer in addition to its role in the closed reinforcing assembly. In accordance with one aspect of the invention, the reinforcing brace is secured within the drawer and extends at least partially across the width of the drawer. The brace has two spaced apart members and a cross member connected to and extending between the wing members adjacent an inside surface of the inner liner of the drawer. Each of the wing members has a forward central portion and recessed opposing wing end portions extending from the forward central portion and secured within the drawer. One of the cross member and the forward central portion has an outward facing surface positioned across a corresponding one of spaced apart mounting support apertures located in the inner liner of the drawer. The wing members and the cross member are adapted for securement with a corresponding drawer mounting bracket at the outward facing surface.











BRIEF DESCRIPTION OF THE DRAWINGS




For a better understanding of the nature and objects of the present invention, reference may be had to the accompanying diagrammatic drawings in which:





FIG. 1

is a front perspective view of a bottom mount refrigerator having a pull out drawer showing the closed reinforcing assembly of the present invention;





FIG. 2

is a perspective view showing the closed reinforcing assembly of the present invention in more detail;





FIG. 3

is a plan sectional view of the refrigerator of

FIG. 1







FIG. 4

is a sectional view taken at section


4





4


of

FIG. 3

;





FIG. 5

a end view of the reinforcing bracket assembly of the present invention;





FIGS. 6 and 7

are respectively side and partial perspective views of the guide rail assembly of the present invention;





FIGS. 8 and 9

are diagrammatic views showing the mounting of the drawer container basket to the guide rails;





FIG. 10

is perspective view of the brace assembly and refrigerator drawer of the present invention;





FIG. 11

is a end view of the brace assembly of the present invention; and,





FIG. 12

is a partial sectional view showing the corner bracket mounting of the terminal end portion of the wing member to the outer panel of the drawer.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




In

FIG. 1

, a bottom mount refrigerator appliance has a cabinet


10


that has an upper fresh food compartment


12


, closed by door


26


, and a lower freezer compartment


14


. The lower food or freezer compartment


14


has opposing liner side walls


16


to which are mounted telescopic guide rails


18


for supporting pull out drawer


20


. In

FIG. 1

the pull out drawer


20


is pulled in direction of arrow


22


to the open position shown where the drawer


20


extends across and is spaced forwardly of the open front


24


of compartment


14


.




It should be understood that the insulated cabinet


10


typically comprises a metal outer panel or shell


28


of a thin gauge of steel and an inner liner


30


which is spaced from the metal shell by insulation (not shown in FIG.


1


). The insulation is typically a foamed in place polyurethane insulation which expands to fill the gap between the outer shell


28


and inner liner


30


. The cabinet inner liner


30


may be either metal or plastic and in this preferred embodiment is plastic.




The lower pull-out drawer


20


also comprises an outer metal panel or shell


32


and a drawer inner liner


34


(FIG.


3


). The drawer liner


34


typically comprises a plastic material.




Referring to

FIGS. 1

to


3


,


6


and


7


the drawer


20


is mounted with its inner liner


34


facing the open front


24


of the lower food compartment


14


by mounting brackets


40


and telescopic guide rails


18


. The telescopic guide rails


18


comprise two opposing telescopic guide rails


18


mounted to a respective one of the opposing liner side walls


16


of the freezer compartment


14


. The guide rails


18


as shown in

FIG. 6

, comprise a stationary portion


50


mounted by screws


52


to the liner side wall


16


of compartment


14


. The stationary guide rails


50


each include a U-shaped bracket portion


54


at a forward end thereof adjacent the opening


24


of the compartment


14


. The U-shaped bracket portion


54


of the stationary guide rail


50


receives an extending intermediate U-shaped guide bracket


56


that is adapted to slide within the U-shaped


54


of the stationary guide rail


50


. The intermediate bracket


56


carries along it's central portion


58


a bar shaped rail


60


which is positioned and secured within the bracket


56


. The rail


60


is attached by rivets


62


to a first rail end bracket


64


. As shown in

FIG. 6

, the first telescopic guide rail


18


is fully extended such that the first rail end bracket


64


extends through the open front


24


of the lower food compartment


14


. The first rail end bracket further has tabs


66


which extend inwardly and upwardly towards the interior of the food compartment


14


when the guide rail


64


is recessed directly within the compartment


14


. To effect this, the intermediate bracket or rail portion


56


slides within the bracket


54


bringing the first end bracket


64


back within the open front


24


of the compartment


14


.




As shown in

FIGS. 1

,


8


, and


9


, a basket


68


extends between the guide rails


18


and has a shoulder or side arm supporting portion


70


that passes over and extends along the liner side walls


16


and is seated upon both of the tab members


66


. The telescopic rails


18


support the basket


68


for supporting food articles.




To secure the drawer


20


to the guide rails


18


, a pair of mounting brackets


40


are used. In

FIGS. 2

,


3


, and


7


, one of the mounting brackets


40


is shown to comprise a front plate


42


and a side plate


44


. The front plate


42


is positioned at right angles relative to the side plate


44


. The mounting brackets


40


comprise a steel material having a thickness in the order of ⅛ of an inch. The side plate


44


is secured to the first end rail


64


. The first end rail


64


includes four apertures


72


,


72


A. Three apertures


72


are shown for the rail


64


. The side plate


44


of the mounting bracket includes four apertures


74


. The apertures


74


align with the apertures


72


by placing the side plate


44


flush against the first end rail


64


. Thereafter, a fastener in the form of a threaded screw (not shown) is passed through the aligned apertures and has a head for engaging the outside of the first rail


64


.




The brackets


40


are mounted to the inner liner


34


of the drawer


20


by the front plate


42


. The front plate


42


has a series of apertures


83


throughwhich fasteners (not shown) pass to mount drawer


20


to bracket


40


and thus to guide rails


18


.




Referring to

FIGS. 1

,


2


,


3


,


10


and


11


, the drawer


20


is a pull out drawer or door that is pulled out horizontally from the cabinet


10


in the direction of arrow


22


. The pull out drawer


20


comprises outer drawer panel


32


having a generally flat metal sheet with rearwardly extending side walls


36


and in-turned flanges


38


extending generally parallel to the flat sheet


32


. The inner drawer liner


34


comprises a plastic liner having a peripheral flange


46


secured with the in-turned flanges


38


of the outer drawer panel


32


. Foam insulation


48


is foamed in place between the inner drawer liner


34


and the outer drawer panel


32


. The inner drawer liner


34


has two spaced apart mounting support apertures


76


as best seen in FIG.


10


.




In accordance with an aspect of the present invention, a reinforcing brace


90


is secured within the drawer


20


extending at least partially across the width of the drawer


20


. The brace


90


has two spaced apart wing members


92


and a cross member


94


connected to and extending between the wing members


92


adjacent an inside surface of the drawer inner liner


34


. The wing members


92


may comprise a metal plate and in the preferred embodiment are made from a glass reinforced nylon.




Referring to

FIGS. 2

,


3


,


10


and


11


the wing members


92


have a forward central portion


96


and recessed opposing wing end portions


98


extending from the forward central portion


96


and secured within the drawer


20


. The forward central portion


96


has an outward facing surface


100


positioned across a corresponding one of the spaced apart mounting support apertures


76


that is substantially flush with the inner drawer liner


34


for securement with a corresponding drawer mounting bracket


40


. A gasket


310


(

FIG. 10

) surrounds the periphery of the mounting support aperture


76


and is placed on the outward facing surface


100


. Gasket


310


acts as a seal for the inner drawer liner


34


and the outward facing surface


100


. Gasket


310


may also provide a cushion for supporting the door mounting brackets.




The cross member


94


comprises a substantially rectangular frame having two side portions


102


overlapping the central portions


96


of each wing member


92


. The central portions


96


of the wing members


92


has an inside surface


104


that has posts


106


extending into the drawer


20


and the cross member


94


has side portions


102


with first corresponding apertures


108


throughwhich the posts extend to locate the cross member relative to the wing members


92


prior to foaming insulation into the drawer cavity. Further, each of the central portions


96


of the wing members


92


has tabs


110


with barbs extending into the drawer


20


and the side portions


102


of the cross member


94


has second corresponding apertures


112


throughwhich the tabs


110


extend to locate and lock the cross member


94


relative to the wing members


92


.




The central portions


96


of the wing members


92


and side portions


102


of the cross member


94


overlapping the central portions


96


have aligned apertures


111


for receiving bracket mounting fasteners (not shown) passing through brackets


40


and brace


90


.




Each of the recessed wing end portions


98


slopes into the drawer


20


away from the inner liner


34


at an angle which varies depending on the drawer height. The wing end portions


98


have terminal end portions


114


that preferably extend parallel to the central portion


96


. The wing end portions include apertures


116


and side flanges


118


for improving rigidity and formation with the foam when foamed into the drawer


20


. The terminal end portion


114


is secured with the outer panel


32


of the drawer


20


. The terminal end portion


114


is preferably secured with the outer panel


32


of the drawer


20


through a corner support bracket


300


(FIGS.


10


and


12


). The bracket


300


has a first portion


302


extending adjacent the terminal end portions


114


of the wing member and secured thereto by stud fastener


305


. The bracket


300


has a base support portion


301


that extends at right angles to portion


302


and is secured against an inside surface of a side wall of the outer drawer panel


32


.




The brace


90


so mounted and foamed in place within drawer


20


provides a local drawer reinforcing structure that is able to distribute drawer


20


loading forces across the drawer


20


away from and independent of the drawer liner


34


. The brace


92


is able to connect at the wing number central portions


96


directly to brackets


40


through aperture


76


in the drawer liner


34


without placing a load on the drawer liner


34


.




In accordance with another aspect of the present invention, the refrigerator cabinet


10


has a reinforced drawer guide rail support assembly


120


as shown in

FIGS. 1

to


5


. The reinforced drawer guide rail assembly


120


comprises the pair of telescopically extendable drawer supporting guide rails


18


as described previously each mounted to one of the opposing liner side walls


16


and to the insulated drawer


20


such that the drawer


20


slides into a sealing engagement with the cabinet


10


across the open front


24


when the drawer


20


is closed.




The reinforced guide rail support assembly


120


includes a pair of reinforcing bracket members


122


located within the cavity


124


defined between cabinet outer panel


28


and liner


30


. The bracket members


122


, each have a side reinforcing portion


126


extending along the liner side wall


16


adjacent a corresponding one of the guide rails


18


and mounted to an inside surface


128


of the liner side wall


116


by fasteners


52


passing through the guide rails


18


and liner side walls


16


. The side reinforcing portions


126


have support flanges


130


extending into and engaging the foam


48


for providing local reinforcement to the liner side walls


16


.




The reinforcing bracket members


122


each have a rear wall portion


132


extending orthogonal from the respective side reinforcing portions


126


adjacent to and in contact with the rear wall


134


of the cabinet interior liner


30


. The rear wall portions


132


are secured to each other to form a continuous arm


132


interconnecting and reinforcing the side reinforcing portions


126


to structurally support the liner side walls


16


of the liner


30


and from flexing outwardly or inwardly from each other adjacent the guide rails


18


. At the same time, this feature prevents load or stress transfer to the plastic liner.




Each of the rear wall portions


132


has a flat surface


136


adapted to rest against the rear wall


134


of the inner liner


30


and a rib


138


extending into the cavity


124


to strengthen the rear wall portion


132


. Each of the rear wall portions


132


has overlapping end portions


140


with flanges


142


extending into the cavity


134


to positively locate the end portions


140


. The overlapping end portions


140


have apertures


144


for receiving fasteners (not shown) to secure the overlapping end portions


140


in fixed relation to each other.




The reinforced drawer guide rail support assembly


120


further includes a pair of opposed recessed liner slots


150


(

FIG. 4

) each extending horizontally along a corresponding one of the opposing liner side walls


16


. Each of the telescopically extendable guide rails


18


preferably comprises three arms, two of which extend telescopically and a third arm which is mounted within the liner slots


150


to one of the opposing liner side walls


16


and to the side reinforcing portions


126


located in the cavity


124


.




In accordance with another aspect of the present invention, the closed reinforcing assembly


200


comprises the combination of the assemblies described hereinabove for the preferred embodiment. That is to say, the closed reinforcing assembly


200


comprises:




the reinforcing brace


90


secured within the drawer


20


,




a pair of telescopically extendable guide rails


18


each mounted to one of the opposing liner side walls


16


and each having a first rail end


64


adjacent the open front


24


when the drawer


20


is closed and passing through the open front


24


when the drawer


20


is open,




the pair of reinforcing bracket members


122


located within the cavity


124


,




the pair of mounting brackets


40


for mounting the insulated drawer


20


to the side rails


18


such that the drawer


20


slides into a sealing engagement with the cabinet


10


across the open front


24


when the drawer


20


is closed,




the mounting brackets


40


each having a side plate


44


secured by at least one first fastener means to the first rail end


64


of a corresponding one of the pair of guide rails


18


, and a front plate


42


secured by at least one second fastener means against a corresponding one of the wing members


92


adjacent the drawer mounting bracket aperture


76


,




the closed reinforcing assembly comprising the reinforcing brackets


122


, the guide rails


18


and the reinforcing brace


92


, maintains the structural integrity of the cabinet


10


and drawer


20


for loads carried by the guide rails


18


.




During drawer manufacture, it should be understood that the insulation may be formed into a completed drawer so as to adhere to inside surfaces of the inner drawer liner and the outer drawer panel. Preferably, the insulation is foamed into a partially completed drawer comprising the outer drawer panel and the reinforcing bracket assembly of the present invention. Subsequently, the drawer liner is attached to the outer drawer panel to complete the drawer assembly.




Certain preferred embodiments of the invention have been described in detail. From a reading of this disclosure, obvious modifications will be evident to those skilled in the art without departing from the spirit of the invention disclosed or from the scope of the appended claims.



Claims
  • 1. A pull out drawer for closing an open front of a refrigerator appliance comprising:an outer drawer panel; an inner drawer liner secured to the outer drawer panel, the inner drawer liner having two spaced apart mounting support apertures; a reinforcing brace secured within the drawer extending at least partially across the width of the drawer and having two spaced apart wing members and a cross member connected to and extending between the wing members adjacent an inside surface of the inner liner; each of the wing members having a forward central portion and recessed opposing wing end portions extending from the forward central portion and secured within the drawer, one of the cross member and the forward central portions of the wing members having outward facing surfaces each positioned across a corresponding one of the spaced apart mounting support apertures for securement with a corresponding drawer mounting bracket, and insulation positioned between the inner drawer liner and the outer drawer panel.
  • 2. The drawer of claim 1 wherein each outward facing surface is substantially flush with the inner drawer liner.
  • 3. The drawer of claim 1 wherein each central portion of the wing members have an inside surface adapted to position the cross member relative thereto prior to positioning the insulation.
  • 4. The drawer of claim 3 wherein each central portion of the wing members has posts extending into the drawer, and the cross member has side portions with first corresponding apertures throughwhich the posts extend to locate the cross member relative to the wing members.
  • 5. The drawer of claim 4 wherein each central position of the wing members has tabs with barbs extending into the drawer, and the side portions of the cross member has second corresponding apertures throughwhich the tabs extend to locate and lock the cross member relative to the wing members.
  • 6. The drawer of claim 3 wherein each central position of the wing members and side portions of the cross member overlapping the central portions have aligned apertures for receiving bracket mounting fasteners.
  • 7. The drawer of claim 1 wherein the cross member comprises a substantially rectangular frame having two side portions overlapping the central portion of each wing member.
  • 8. The drawer of claim 7 wherein each central portion of the wing members has posts extending into the drawer, and the side portions of the cross member have first corresponding apertures throughwhich the posts extend to locate the cross member relative to the wing members.
  • 9. The drawer of claim 8 wherein each central position of the wing members has tabs with barbs extending into the drawer, and the side portions of the cross member have second corresponding apertures throughwhich the barbs extend to locate and lock the cross member relative to the wing members.
  • 10. The drawer of claim 9 wherein each central portion of the wing members and side portions of the cross member overlapping the central portions have aligned apertures for receiving bracket mounting fasteners.
  • 11. The drawer of claim 7 wherein each central position of the wing members and side portions of the cross member overlapping the central portions have aligned apertures for receiving bracket mounting fasteners.
  • 12. The drawer of claim 11 wherein each of the recessed wing end portions slope into the drawer away from the inner liner and is surrounded by insulation.
  • 13. The drawer of claim 12 wherein each of the wing end portions has a terminal end portion secured with the outer panel of the drawer through a corner support bracket.
  • 14. The drawer of claim 12 wherein the wing end portions include apertures and side flanges for improving formation within the drawer with the insulation.
  • 15. The drawer of claim 14 wherein the wing members comprise a glass reinforced nylon.
  • 16. The drawer of claim 7 wherein a gasket extends around each of the peripheries of the mounting support apertures to seal the inner drawer liner to the outward facing surface.
  • 17. The drawer of claim 7 wherein the insulation is foamed in place insulation that adheres to the inner drawer liner.
  • 18. The drawer of claim 7 wherein the insulation is foamed in place and does not adhere to the inner drawer liner.
  • 19. The drawer of claim 1 wherein each of the recessed wing end portions slop into the drawer away from the inner liner and is surrounded by insulation.
  • 20. The drawer of claim 19 wherein each of the wing end portions has a terminal end portion secured with the outer panel of the drawer.
  • 21. The drawer of claim 19 wherein the wing end portions include apertures, and side flanges for improving formation within the drawer with the insulation.
  • 22. The drawer of claim 21 wherein the wing members comprise a glass reinforced nylon.
  • 23. The drawer of claim 1 wherein a gasket extends around each of the peripheries of the mounting support apertures to seal the inner drawer liner to the outward facing surface.
  • 24. The drawer of claim 1 wherein the insulation is foamed in place insulation that adheres to the inner drawer liner.
  • 25. The drawer of claim 1 wherein the insulation is foamed in place and does not adhere to the inner drawer liner.
  • 26. The drawer of claim 1 wherein outer drawer panel comprises a generally flat metal sheet with rearwardly extending side walls and in-turned flanges extending generally parallel to the flat sheet and wherein the inner drawer liner comprises a plastic liner having a peripheral flange secured with the in-turned flanges of the outer drawer panel.
Priority Claims (1)
Number Date Country Kind
2344923 Apr 2001 CA
Parent Case Info

This application is a divisional application of U.S. patent application Ser. No. 09/963,626 filed Sep. 27, 2001, entitled “REINFORCED REFRIGERATOR CABINET CLOSING DRAWER” still pending.

US Referenced Citations (18)
Number Name Date Kind
2104939 Whalen Jan 1938 A
2306802 Harbison Dec 1942 A
2413597 Armstrong Dec 1946 A
2573272 Petkwitz Oct 1951 A
2682754 Eck Jul 1954 A
3024075 Howe Mar 1962 A
4013434 Kronenberger et al. Mar 1977 A
4107833 Knight et al. Aug 1978 A
4190305 Knight et al. Feb 1980 A
4448464 Reichert et al. May 1984 A
4462645 Ballarin et al. Jul 1984 A
4832422 Fortmann May 1989 A
5040856 Wilkins et al. Aug 1991 A
5366284 Baker et al. Nov 1994 A
5366285 Borgen et al. Nov 1994 A
5486045 Dasher Jan 1996 A
5893620 Birgelis Apr 1999 A
6447083 Chiapetta et al. Sep 2002 B1
Foreign Referenced Citations (2)
Number Date Country
460275 Sep 1968 CH
975649 Mar 1951 FR