US3557975A

US3557975A - Pusher assembly for freezers

Info

Publication number: US3557975A
Application number: US806982A
Authority: US
Inventors: Pasquale Amerio
Original assignee: ST Regis Paper Co
Current assignee: ST Regis Paper Co
Priority date: 1969-03-13
Filing date: 1969-03-13
Publication date: 1971-01-26
Anticipated expiration: 1988-01-26
Also published as: ES377434A1; FR2034900B1; NO132584C; FR2034900A1; DE2012615B2; DE2012615A1; NL7003533A; GB1259073A; SE359911B; DE2012615C3; NL163866B; NL163866C; NO132584B

Abstract

In a freezer having contact freezer plates which are vertically movable into register with a front charging opening, a pusher assembly for intermittently feeding a single row of boxes from a conveyor through said opening and for alternatively removing all the boxes from each plate through a discharge opening, for example, when the freezer is to be defrosted said assembly including a pusher bar movable generally in the plane of said charging opening, a plurality of drive rods for advancing the pusher bar, trackways extending forwardly from the front of the freezer supporting said rods for sliding movement and a pusher frame secured at the forward ends of said drive rods.

Description

United States Patent Inventor Pasquale Amerio Ringwood, NJ.

Appl. No. 806,982

Filed Mar. 13, 1969 Patented Jan. 26, 1971 Assignee St. Regis Paper Company New York, N.Y. a corporation of New York PUSI-IER ASSEMBLY FOR FREEZERS Primary ExaminerGeraId M, Forlenza Assistant Examiner-Raymond B. Johnson Att0meyCIyde I-I. Haynes and Ferdinand F. E. Kopecky ABSTRACT: In a freezer having contact freezer plates which are vertically movable into register with a front charging opening, a pusher assembly for intermittently feeding a single row of boxes from a conveyor through said opening and for alternatively removing all the boxes from each plate through a discharge opening, for example, when the freezer is to be defrosted said assembly including a pusher bar movable generally in the plane of said charging opening, a plurality of drive rods for advancing the pusher bar, trackways extending forwardly from the front of the freezer supporting said rods for sliding movement and a pusher frame secured at the forward ends of said drive rods.

PATENTEnJAn'zslsn v T 31557875 I SHEETlUFS PASQUALE AMERIO INVENTOR.

JOHN P. CHANDLER HIS ATTORNEY.

PATENTED JANZS I971 SHEU 2 OF 3 INVENTOR.

PASQUALE AMERIO JOHN P. CHANDLER HIS ATTORNEY.

PATENTED JANZSIQ?! sum 3 [1F 3 llj g HO 00 I02 IOI INVENTOR.

PASQUA LE AMERIO JOHN P. CHANDLER HIS ATTORNEY.

PUSIIER ASSEMBLY FOR FREEZERS This invention relates to the freezing of foods and relates more particularly to means for freezing boxes of unfrozen food in an automatic freezing system. An automatic freezer for boxes of foods wherein a full complement of the boxes is fed to one of a plurality of superimposed freezing plates, mounted in a frame or cradle, is shown in my U. S. Pat. No. 3,271,973. When one freezing plate is filled, the entire array of plates in superimposed relation is moved vertically to position another plate to receive the boxes.

An automatic feeding assembly for the boxes is shown in my U. S. Pat. No. 2,812,050. The boxes are fed to a feed opening in the freezer housing with a cavity between the contact freezer plates lined up with the opening. The pusher then moves a row of the boxes into the empty space and this continues until the plate is filled, at which time the assembly moves vertically to position the next empty space in line with the feed opening.

A unique feature of this assembly is that it provides for continuous operation, filling all the plates with boxes and at the end of the freezing cycle the boxes are pushed out through a discharge opening on the opposite side of the freezer as rows of unfrozen boxes are successively pushed in by the pusher assembly.

It has been found, however, that all the boxes must be periodically discharged from time to time in order to clear the freezer and defrost and remove all accumulated ice. The pusher assembly of my U. S. Pat. No. 2,812,050, cannot perform the latter operation since the arrangement is such that the maximum travel of the pusher is not much greater than the width of the widest boxes of food, i.e., about inches. The freezer plate, however, may be 72 inches in width. Accordingly, at defrosting time the boxes are pushed out manually by crude devices resembling hand snow pushers.

The principal object of the present invention is to provide a pusher assembly which, while different in structure from that shown in my U. S. Pat. No. 2,812,050, will perform the first function of that apparatus, namely, pushing one row of boxes onto the plate at a time. The pusher of the present invention will also clear the plate, at one stroke, of all the boxes, just prior to the defrosting operation.

The mechanism includes a pair of drive rods with the pusher assembly mounted on the forward ends of the rods. The rods are suitably mounted for sliding movement in trackways which extend horizontally from the front face of the freezer at the charging opening. A rack, driven by a gear, is carried by each rod and, if the installation is in an area where space is plentiful, the rods and trackways extend straight out a distance in excess of the width of the contact freezer plates. In almost all instances, however, space in freezer plants is scarce and the trackways are curved upwardly at a point inches or so from the freezer. The rods are, therefore, made in hinged sections and links of a conventional drive chain secured thereto with about twelve links to each section. Hydraulic cylinders and pistons can be employed to drive the rods, but I prefer to use hydraulic motors to drive sprocket gears which engage the chain links. Substantially, the same automatic control mechanism as that shown in my U. S. Pat No. 2,812,050 can be used, and, when the plates are to be cleared, the drive rods can be switched to manual control.

In the drawings:

FIG. 1 is a front elevation of a continuous automatic freezer equipped with the pusher assembly of the present invention;

FIG. 2 is a side elevation thereof and showing the front and rear endless feed conveyor in section;

FIG. 3 is a horizontal section taken on line 3-3 of FIG. 1;

FIG. 4 is a broken section showing a side elevation of one of the pusher arms;

FIG. Sis a section taken on line 55 of FIG. 4;

FIG. 6 is a view similar to that shown in FIG. 4 but showing the position of the parts when the pusher has moved well into the interior of the empty space between two freezer plates;

FIG. 7 is a section showing the details of a-modified pusher;

FIG. 8 is an enlarged view of the modified pusher raising mechanism to enable the pusher bar to clear the oncoming boxes on the return stroke.

The freezer housing is shown at 10 supported by a suitable frame structure 11, supporting the front and rear walls 14. A control panel 15 is mounted on the front wall and this wall also has an elongated rectangular charging opening 16 while the rear wall has a similar discharge opening 18. The rows of boxes 20 are fed to a rectangular contact freezer plate 19 which is one of a plurality of such plates in a bank of plates suitably supported in a cradle (not shown) which intermittently moves vertically by increments, during charging, until all the plates in the freezer are filled. The plate 19 to which the boxes are fed, and the plate immediately above the plate 19 defines a charging space and during freezing both of these plates engage the boxes. In order to get the boxes into the space between the plates, the spacing must be increased and means for effecting this spacing is shown in my aforesaid U.S. Pat. No. 3,271,973. The freezing is not interrupted during this charging and, in a normal operation, when the last plate is filled, the contents of the boxes on the first plate to be charged are fully frozen, at which time the charging and discharging operation starts anew. This operation continues from day to day until it is necessary to defrost the freezing apparatus, usually once a week.

The boxes are fed to opening 16 by means of an endless conveyor belt 21 supported between two

rolls

22 and 24, the latter of which has a pulley 26 driven by a belt 28 from another pulley connected to the shaft of a motor 29. The upper course of conveyor belt 21 is supported by a platen 30 mounted on

fixed sidewalls

31 and 32, the latter supporting a flange 34 which iscoplanar with the belt 21 and one of the freezer plates 19. This flange may be a separately formed member, as shown in FIG. 2, or may be formed integrally with the inner sidewall 32 as shown at 34' in FIG. 4. The lower course 35 of the belt 2! travels along a lower wall 36 of the boxlike conveyor support 30-3132. This support is mounted on the front of the freezer housing by brackets 39. A similar conveyor assembly is positioned at the rear of the freezer.

The pusher assembly includes a frame 40 mounted at the forward ends of a pair of drive rods 41. The frame 40 is shown in FIGS. 2 to 4 as an angle bar, and the pusher bar is formed like a piano hinge with a first fixed horizontal section 42 secured on the upper horizontal part of the angle bar 40 and a second hinged section 44 which normally is in a vertical position and supports the pusher bar 46 on its front face. This pusher bar contacts the boxes 20 as they are pushed into the freezer. A hinge pin 47 is shown between the two

sections

42 and 44 of the pusher bar is shown at 47. The vertical section 48 of the frame or angle bar 40 limits rearward pivotal movement of the second hinge section 44. As the pusher assembly moves the row of boxes 20 into the freezer, an oncoming row moves downstream on conveyor belt 21. On the return stroke, the hinged push bar section 44 is moved upwardly over the boxes.

The drive rods 41 move horizontally from the front towards the rear of the freezer and, if there were an empty space in front of the freezer equal to the width of the freezer plate (usually about 72 inches), these driven rods could be supported in straight horizontal tracks. Space, however, is almost always in short supply in freezer plants and for this reason the drive rods are formed in articulated sections 49 having hinged connections at 50 and having square end faces 51 which are vertical when the rod sections are horizontal.

Each rod section of the pusher assembly is mounted for sliding movement in a track structure having a lower horizontal terminal section 52 mounted as by welding at the lower end of a square tube 54 on the front wall of the freezer housing. At its rear, the track structure has an upwardly extending vertical section 56 joined to the horizontal track section 52 by a curved section 58. Square tubes 54 support a substantial portion of the weight of the entire pusher assembly and they can be moved up or down to an adjusted position and secured there by means of threaded adjusting screws 60 passing through slots 61 (FIG. 1) in the tubes. The two tubular supports 54 for the lower end of the pusher assembly are maintained in spaced relation from each other by a cross piece 64 (FIG. 4).

The angle bar or frame 40 supporting the pusher bar has its vertical part 48 cut away at 66 (FIG. at each end and a short plate 68 is secured to the end of the horizontal section of the angle bar 40 by a bolt 70. A block or shim 71 is positioned between plate 68 and track 52 and the three members are welded together. The track structure is reinforced by a square tubular member 72 and friction between the drive rod 41 and the track 52 is reduced by

synthetic plastic liners

74, 75 and 76 made of nylon, Teflon (polytetrafluoroethylene) or other plastic material. Liner 75 is positioned between the side of the rod 41 and the inner wall 78 of square tube 72 while liner 76 is between the other side of the rod and block or shim 71. This liner 76 may extend rearwardly along angle bar 80 (FIG. 3). To the front of the pusher bar the drive rods are guided by a flange or angle bar 80.

Driving of the drive rod 41 is effected by a rack secured thereto and conveniently formed by drive chain links 82 (FIG. 4) welded thereto. A drive shaft 84 is journaled in pillow blocks 86 (FIG. 4) secured to tubes 72 and keyed to this shaft are two sprocket gears 88. A hydraulic motor 90 (FIG. 2) is supported on a base 91 secured to square tube 72 (FIG. 3) and the motor shaft is connected with drive shaft 84 by a coupling 92. This motor 90 drives shaft 84 and the sprocket gears 88 that are keyed thereto. A hydraulic motor for this purpose is preferred to an electric one because of the frequent reversals of direction that are required. Tubular connections 93 and 941 to the motor 90 (FIG. 3) lead to a suitable source of fluid under pressure with controls for rotating the drive sprocket gears 88 a sufficient distance in one direction to move the row of boxes into the freezer, i.e., the distance from A to B as represented in FIG. 2. It is then driven in the other direction to return the pusher bar to its original starting position.

Those skilled in the art may devise any number of simple circuits to control forward and reverse movement of the hydraulic motor but the circuit shown in my US. Pat. No. 2,8l2,050 will serve the purpose admirably. In that patent, the pusher was moved forwardly and backwardly by a cylinder with a piston (FIG. 7) which is driven forwardly and backwardly by fluid under pressure entering the cylinder through the

conduits

70 and 71, the fluid being controlled by a solenoid-actuated valve 72. Volume of fluid there, as here, was the sole factor in controlling the distance of travel and the entire automatic organization, including cylinder 35 and piston 67, can be used in the instant pusher assembly of the present invention. The present pusher operates more effectively with a hydraulic motor, however, but the piston controls can be the same. When the freezer is empty, I start the loading by employing the system disclosed in US. Pat. No. 2,842,253. In that patent, the tops of the incoming boxes are engaged by a soft friction wheel 108 (FIGS. and 11) which rotates at a faster rate than the motor 106 is geared to turn it with an overrunning clutch 107 between the friction wheel 108 and the drive shaft. When a group of boxes completely fllling one row is stopped downstream by a gate, the motor supported on a pivoted bracket is upset and closes a switch which starts the pusher. That system thus operates much like the present system, filling each contact freezer plate successively.

When it is desired to defrost the freezer, the automatic controls may be cut out and be replaced by manual control. This operation simply involves continuing movement of the drive rods 41 and pusher bar clear across the plate to position C in FIG. 2. For this operation, it may be preferred to have the articulated drive rod section 49 travel on the plate rather than in spaced relation thereto as in FIG. 2. This is readily accomplished by loosening adjusting screws and allowing the entire pusher assembly to drop a few inches. The square ends 51 of the rod sections 49 prevent the sections from buckling. Ac-

tually), however, not too much force is required for this operatron ecause the frozen bond between the box'es and the plate is broken in the first 1: inch of travel.

In FIGS. 7 and 8 is shown a modified hinged pusher bar which is driven by power means both for raising and lowering the same to vertical pushing position. An angle bar again forms a frame at the forward ends of the articulated pusher rods 49. The horizontal part 96 of this bar is mounted on a base 98 secured to a bracket 99 secured by bolts to the forward end of the drive rods. One part 100 of a two-part hinge is secured to the upper face of angle bar 96 and the other part 101, which is pivoted to the first part at 102, is normally vertical and is secured to brackets 106 which support pusher bar 107.

A hydraulic cylinder 108 with an internal piston (not shown) and a piston rod 109 is connected with the upper end of each bracket 106 by a link 110 pivoted at each end. Fluid under pressure is supplied to opposite ends of the cylinder by conduits 112 and 113. A solenoid valve such as is shown at 72 in FIG. 7 of US. Pat No. 2,8 I 2,050 may be used to control the up and down movement of the hinged pusher bar. When moving single rows into the freezer from position A to position B (FIG. 7 of the drawings of this application), the bracket 106 may be swung to position C on the return stroke and thus avoid any contact with the boxes on the conveyor belt 21.

Iclaim:

1. A pusher assembly for intermittently feeding a single row of boxes from a conveyor through a front charging opening in a freezer having contact freezer plates which are vertically movable into register with said opening, and for alternatively removing all the boxes from each plate through a discharge opening, said pusher assembly including a pusher bar movable generally in the plane of said charging opening, a plurality of drive rods for advancing the pusher bar, trackways extending forwardly from the front of the freezer supporting said rods for sliding movement, a frame secured at the forward ends of said drive rods, a pivotal connection between the pusher bar and the frame to permit the bar to raise over the oncoming boxes on the conveyor after a first row has been pushed into the freezer, a motor for advancing and retracting the drive rods to successively feed said rows into the freezer, and means for moving the pusher assembly clear across the plate to remove all boxes therefrom in one stroke.

2. The apparatus of claim 1 wherein racks are secured to the drive rods and gears driven by the motor engage the racks.

3. The apparatus of claim 1 wherein said drive rods are formed in articulated sections and each trackway has a section extending forwardly from the freezer, an upwardly extending section at the free end thereof and a curved section therebetween.

4. The apparatus of claim 1 wherein the pusher assembly is vertically adjustable to 'p'erinit it to be lowered when the pusher bar and supporting means therefor is in position to move clear across the plate.

5. The apparatus of claim 1 wherein the motor is a reversible hydraulic motor.

6. The apparatus of claim 1 wherein the pusher assembly is automatically controlled during feeding of single rows of boxes to the freezer.

7. The apparatus of claim 1 wherein the row of boxes cams the pivoted pusher bar upwardly to ride over the boxes on the return stroke.

8. The apparatus of claim 1 wherein power driven means are provided to raise the pivoted pusher bar.

9. The apparatus of claim 1 wherein the tracks over which the drive rods move have plastic liners to reduce friction.

Claims

4. The apparatus of claim 1 wherein the pusher assembly is vertically adjustable to permit it to be lowered when the pusher bar and supporting means therefor is in position to move clear across the plate.

5. The apparatus of claim 1 wherein the motor is a reversible hydraulic motor.