US3390808A

US3390808A - Milk crate

Info

Publication number: US3390808A
Application number: US576957A
Authority: US
Inventors: Rehrig Houston; Richard F Gildart
Original assignee: Rehrig Pacific Co Inc
Current assignee: Rehrig Pacific Co Inc
Priority date: 1966-09-02
Filing date: 1966-09-02
Publication date: 1968-07-02
Anticipated expiration: 1985-07-02
Also published as: DE1586881A1

Description

July 2,. 1968 H, REHRK; Em 3,390,808

MILK CRATE Filed Sept. 2, 1966 INVENTORJ HOUSTON REHRIG I RICHARD F GILDART v ATTORNEYS.

United States Patent 3,390,808 MILK CRATE Houston Rehrig, Pasadena, and Richard F. Gildart,

Montebello, Calif., assignors to Rehrig Pacific Company, Los Angeles, Calif., a corporation of California Filed Sept. 2, 1966, Ser. No. 576,957 Claims. (Cl. 220-73) ABSTRACT OF THE DISCLOSURE A molded plastic milk crate having side panels the upper portion of which are formed as an integrally molded open grid providing substantial rigidity in a direction normal to the side panels while permitting differential shrinkage within the plane of the side panels to minimize buckling of the panels upon removal of the crate from the forming mold. The crate is provided with substantially triangular shaped hand-holds having substantially horizontal upper edges and having lower edges inclined downwardly to act as a cam and thereby prevent articles inserted in the crate from engaging and hanging on the lower edge of the hand-hold.

This invention relates to material handling crates, and more particularly to crates molded from a synthetic resin material and suitable for handling milk bottles, cartons, or the like.

Milk crates which are injection molded from a synthetic resin material, hereinafter referred to broadly as plastic, have many advantages over the conventional wire frame or wooden milk crates, and are rapidly replacing these prior art milk crates in many geographic-a1 areas. Among the advantages of the plastic crates is their light weight, the ease with which they may be cleaned, and their neat and attractive appearance which is not materially altered with age. However, some difficulty has been experienced with the molded plastic crates due, primarily, to the tendency of the plastic material of newly molded crates to shrink and become distorted or warped after the crate is removed from the forming mold. While this problem has been reduced by employing a relatively heavy section of material .and/ or other reinforcing at the junction between the bottom and side walls of the crate, and by employing a relatively heavy metal reinforcing element around the top periphery of the crates, it has been found that the relatively large, thin-walled side panels still have a tendency to buckle slightly, even when reinforcing ribs or fins are provided on the outer surface of the side panels.

This buckling is not only unsightly, but also frequently causes difficulty in filling the crates, particularly with paper or plastic cartons of milk which have relatively sharp corners between their bottom and side panels. Buckling of the crate side panels frequently causes the lower edge of the conventional hand-holds to project inwardly beyond the portion of the crate above the handhold, which is normally held rigid by the metallic reinforcing ring, so that cartons of milk being dropped into the crate frequently hang on this inwardly projecting ledge rather than to drop freely to the bottom of the crate. This is a serious difficulty, particularly with high speed automatic crate loading apparatus commonly employed in modern dairies, as any delay in a carton dropping to the bottom of the crate may result in the carton becoming damaged or the loading equipment fouled.

Accordingly, it is the primary object of this invention to provide a molded plastic milk crate having means for reducing the buckling of the side panels of the crate.

' Another object of the invention is to provide a molded plastic milk crate having means for eliminating the tend- ICC ency of articles being dropped into the crate from hanging on the hand-hold provided in the side panels of the crate.

In the attainment of the foregoing and other objects, an important feature of the invention resides in providing a molded plastic crate in which the upper segment of the side panels of the crate are formed as an open grid, with the thickness of the grid segment in the direction normal to the panel being substantially greater than the transverse dimension of the individual grid elements to provide a relatively rigid lightweight panel having great resistance to buckling. A generally triangular shaped hand-hold is provided in the grid section of the side panel, with one side of the triangle being substantially parallel to the top of the crate and spaced adjacent to and below the conventional metallic reinforcing ring. The remaining two sides of the hand-hold are inclined downwardly at a relatively large angle so that these lower sides of the handhold will act as a cam to deflect falling cartons of milk inwardly when the bottom portion of the handle has buckled inwardly.

Other objects and advantages of the invention will become apparent from the following specification taken from the accompanying drawings, in which:

FIG. 1 is an elevation view of a molded plastic milk crate embodying the present invention; and

FIG. 2 is a fragmentary sectional view, taken on line 22 of FIG. 1, with a milk carton, shown in phantom, being dropped into the crate.

Referring now to the drawings, a molded plastic milk crate embodying the invention is illustrated generally by the reference numeral 1, and includes :a generally rectangular bottom panel 2 and side panels 3 extending upwardly from the side edges of the bottom panel 2. Side panels 2 are all identical and therefore only one has been shown or will be described. A pair of vertically spaced flanges 4, 5 are integrally molded around the top of the crate and project outwardly therefrom to define a channel for receiving an endless metallic reinforcing ring 6. A pair of coined lugs 7 extend upwardly from the metallic reinforcing ring and project into the uppermost flange 4 to firmly secure the upward edge of the side panel 3 to the reinforcing ring.

The side panel 3 of the crate 1 includes a relatively thin, substantially planar lower segment or panel 10 and an integrally molded open grid upper panel segment 11. As is best seen in FIG. 2, the upper panel segment 11 is relatively thick, as compared to the lower panel 10, in the direction normal to the side panel 3, with this thickness ratio being at least 3 to 1 and preferably approximately 4 to 1. Thus while the panel segment 11 is relatively thick and therefore rigid in the direction normal to the side panel 3, it is nevertheless relatively light weight, with the transverse thickness of the individual grid segments 12 being substantially equal to the thickness of the panel 10 to thereby provide for relatively uniform cooling of the side panel upon removal from the injection mold.

While the panel segment 11 is relatively rigid in a direction normal thereto, the open grid readily accommodates any differential shrinking or contraction of the material forming the crate. Therefore, any tendency of the side panel to buckle within this area of the open grid due to shrinkage of the plastic is materially reduced or entirely eliminated.

To facilitate handling of milk crates of this general type, an elongated, laterally extending, hand-hold is normally provided adjacent the top edge of each of the side panels of the crate to thereby provide a handle. In the improved crate according to this invention, the hand-hold 15 is generally triangular in shape, as illustrated in FIG.

3 l l, with one side 16 of the triangle extending parallel to and spaced below flange 5, and with the remaining two side-s 17, 18 extending downwardly and inwardly to intersect at a point spaced a substantial distance from the top of the crate and located along the vertical center plane of the crate. Sides 17 and 18 are inclined at a relatively large angle with respect to side 16, this angle being at least 30 degrees, and in the illustrated embodiment the angle is approximately 45 degrees. This relatively large angle is necessary to provide the camming action, described below, to prevent square bottom milk cartons from hanging on the lower edge of the handle in the event that the side panel is either deflected or buckled inwardly in this .area.

Referring specifically to FIG. 2, it is seen that any inward deflection of the side panel 3 in the area of the intersection of sides 17 and 18 (the bottom ofthe handheld 15) will result in sides 17 and 18 being inclined inwardly from side 16 so that a carton being dropped into the milk crate will engage one or both-of the sides 17,

18 at a point spaced substantially. above this bottom portion of the hand-hold. As the carton continues to drop, it will be cammed inwardly so that, as the carton reaches the bottom of the hand-hold, it is not caught thereon but rather drops freely to the bottom of the crate.

While We have disclosed and described a preferred embodiment of our invention, we wish it understood that we do not intend to be limited solely thereto, but that we do intend to cover all embodiments thereof which would be obvious to one skilled in the art and which come within the spirit and scope of our invention.

We claim:

1. In a milk crate having a generally rectangular bottom panel and integrally molded plastic side panels extending upwardly from said bottom panel, and an endless reinforcing ring extending around the outer periphery of said crate and attached to said side panels adjacent the top edge thereof, the improvement wherein at least two opposing side panels each comprise a substantially planar lower segment and an integrally molded open grid structure defining an upper segment, the inner surface of said lower and upper segments being substantially co-planar substantially and said side panels being completely unsupported intermediate the side edges thereof and intermediate said bottom panel and said reinforcing ring, the dimension of said upper segment in a direction normal thereto being substantially greater than the thickness of said planar segment, and a generally triangular hand-hold formed in the grid segment to provide, incooperation with said reinforcing ring, a carrying handle adjacent the top of each said panel having a hand-hold formed therein, said handheld having one side extending substantially parallel to and spaced 'from the top edge of the associated side panel, with the remaining two sides of the respective hand-hold being inclined downwardly toward one another and forming a part of said open grid structure.

2. The milk cratedefined in claim 1 wherein each of said side panels includes said grid segment and said triangular shaped hand-hold to provide a carrying handle adjacent the top of each side panel of said crate, said grid structure including a plurality of elongated grid segments each extending generally parallel to one .of said remaining two sides, said grid segments cooperating to define a plurality of generally rectangular openings in said upper segment of said side walls.

3. The milk crate defined in claim 2 wherein said grid structure includes a plurality of elongated grid segments each extending generally parallel to one of said remaining two sides of said hand-hold.

4. The milk crate defined 'in claim 1 wherein the included angle between said one triangular side and said other two triangular sides is at least thirty degrees.

5. The milk crate defined in claim 4 wherein the thickness of said side panel within said grid segment is at least three times the thickness of said planar segment.

References Cited UNITED STATES PATENTS 2,530,481 11fi1950 Rawn. 2,743,030 4/1956 Read. 2,970,715 2/1961 'Kappel et al.