US2390455A - Bake oven conveyer - Google Patents

Description

Dec.

4, 1945. J. R. NALBACH BAKE OVEN CONVEYER `Filed oct. 26. 1944 2 sheets-sheet 2' bakeoven conveyers.

'veyen partially` in section, taken Patented Dec. 4, 1945 UNITED STATES PATENT I 01E FI CE. i

BAKE OVEN coNvEYan` 301m n.` Nalbach, `oak Park, n1.,--assignor`to `i Middleby-Marshall Oven Company, Chicago,"

VIlll, a corporation of Illinois v Application october 26,1944, serial iva-560,467

This invention .relates` to; :improvements in VIn` the conveyer constructionv for bake ovens, shown in John R.; Nalbach and `Adolph Haupt application, SerialoNo. 435,774,4led March 23,

1942, now PatenttNo.: 2,369,840, `grantedFebruary 20,v 1945, thereis shown j tray stabilizing mechanism,gincluding track switches, for directing un- `pivoted` ends of trays across gaps orfspaces between horizontal lower maintracks and superjacent arcuatertracks, alongthe latter `of which said unpivoted; ends of :thetrays travel inmovn ing from" one run-o theconveyer to the'other, the track switches being camicontrolled.

n `.The-principal` object of, the present invention isytoirnprove the track switch and related structure shown in said patent by incorporating therein means `for preventing jamming of the moving 4conveyer or tray parts `with :the: track switches in the event the latter `fail to move out of obstructing position, due to failure or improper functioning of thecam controlled means thereof.

Another object of the invention is to provide a. simple track switch structure thatis operable to `anpopen switch position by those approaching portions of the tray conveyer` mechanismfthat will cause jamming of the mechanism in the event the switch structure, due to interference withthe proper functioning ofthe switch oper.-

` ating means, fails to return normally to the open `switch position. Y `Other objects of the vinvention relate to various features of `construction and arrangement i view: of "the right-hand portion of the conveyer shown in Figure 1;

AFigure 3 is a broken `perspective view illustratlng `portions of the track switch and related mechanism;`

`Figure 4 is a` broken top plan view of the conalong lines 4 4 of` Figure 1.

Inthe drawings, .I indicatesgenerally a heatinsulated bakev oven enclosure whichmay be of `any approved construction and within which is located the improved conveyer.` .Therconveyer mechanism, generally, .comprises a` pair of forward sprockets I I, spaced .aparthorizontallm and a pair of aligned rear sprockets I 2 around whichl pass a pair of chains I3. The runs of the chains between thefront andlrearsprockets II andil2 are shown inhorizontal position `and are sup-V ported in such position `loylrneans of a paircf upper tracks I4 and a similar pairof lower tracks I5, the tracks being attached to the inner Walls of the oven structure or to the framework thereof.` As shown in Figure 1, the conveyer mechanism may be operated by means of a mo tor I6 located exteriorly of the ovenythe` motor operating chains VI 'I which, in turn, drive sprockets I8 mounted on axially alignedstub shafts I9 which carry the frontsprockets II. The shafts I9 extend through opposite walls of the oven to the exterior, whereby the driving means for the conveyer are not subjected to` the `intense heat of the oven.

The chains I3 carry trays,` each indicated by the numeral 2D, althoughto some of the latter letter exponentswill befadded for clarity in referencerto particular trays as the disclosure proceeds. i

The trays carry the bread or other bakery productsto be baked, and in the particular embodiment herein illustrated the trays are attached pivotally to opposed portions of the chains I3 by lateral extensions orpivot members 2|, as indicatedin Figure 4. In Figure 4 it will be noted that the tracks I4 and I5 extend inwardly of the oven beyond the chains I3 and thusprovide inner trackways along the inner edges of the `tracks which are indicated by numerals Ha and 15a.` The pivot members 2I extend across the trackways just. mentioned into pivotal en'- gagement with the chains and, hence, are moved with the chains as the latter travel under the `driving action of themotor I6. The forward ends of the trays 20, as shown in Figure 4, are `provided with supporting means therefor in the form of rollers 22 whichare arranged for` support on the trackways Maand I5a on the upper and lower tracks I4 and I5.l It will be seen, therefore, that the trays 2B are supported in horizontal relation as the same move longitudinally in one direction or` other within thefoven.

Referring to Figure 1, it will be seen that if the conveyer mechanism is operating in clockwise direction, the pivotal axis 2I of the respective trays in the upper run ofthe conveyer will be moved arcuately by the chains about the rear sprockets. I2 andthus will be carried fromthe upper rtracks to the lower tracks. For the purpose of supporting the forward ends of such V -trays duringthe arcuate movements thereof from one run of the conveyer to the other,1 mechanism is provided for engaging the forward unpivoted ends of the trays and retaining the same in horizontal alignment with the rear pivoted ends thereof during such arcuate movement. The mechanism herein shown and also disclosed in the above mentioned patent comprises a pair of rotary transfer members 24 each of which is mounted on one oftwo similar stub shafts (see Figure 4) that are driven in synchronism with the sprockets I2 by any suitable mechanism, such as chains 26, sprockets 21, and sprock-V ets 28, the latter being mounted on the stub shafts I2a that carry sprockets I2, said driving mechanism being located exteriorly and on o-pposite'sides of the baking chamber.

The transfer arms 24, as shown in Figure 4, are located substantially in vertical alignment with the respective inner edge portions of the tracks I4 and I5 and, by reason of the drive mechanism above described, the movements thereof are synchronized with the movements of the successive trays so that as the rear end of a tray, such as tray 20a, shown in Figure 2, approaches the rear sprockets I2, one end of eachtransfer arm 24 will be in position, as shown in said figure, to engage rollers mounted co-axially with respect to the adjacent rollers 22. `As the rear pivotedl end 2| of the tray 20a begins its downward arcuate movement about the sprockets I2, the forward unpivoted end lof the tray, supported by the transfer arms 24 will begin to move arcuately downward also, whereby the tray is retainedV during such arcuate movements in horizontal or stabilized relation.

In Figure 1 a tray indicated by the numeral 2Gb is shown in a position midway between the upper andV lower runs of the conveyer. The rear portion of the tracks I4, as described in the above mentioned patent, are cut away sufficiently as at 3| (see Figure 2) to accommodate the arcuate movement of the forward ends of the tray under the guidance of the transfer arms 24. For the purpose of cooperating with the transfer arms in the stabilization of the respective trays during the arcuate movement of the latter, arcuate track members 32 are disposed in the vertical planes of the respective transfer arms 24. The arcuate track members cooperate with the receiving recesses 24a of the arms 24 in guiding the rollers 3|) during the arcuate movement mentioned. Since the rear pivoted ends of the trays extend laterally beyond the vertical planes of the arcuate track members 32, the lower ends of the latter terminate above the lower tracks I5, thereby providing a gap or space between said members.

Such gap or space is required to permit the rear pivots 2| of the trays to pass horizontally along the lower track beneath said arcuate tracks 32 after a tray, such as tray 20e of Figure 1, has reached the lower track I5.

For the purpose of cooperating with the transfer members 24 in guiding the unpivoted ends of the trays across said gaps at the lower ends of the arcuate tracks 32, track switches 33 are provided which are disposed in the vertical planes of 'the respective arcuate tracks. The track switches 33, as shown more clearly in Figure 3, are mounted on stub shafts 34 each of which, on an outer end is provided with a cam follower arm 35 having a cam follower 36' thereon, the latter being actuated by a, cam 3l mounted on the respective shafts 25. The cams 3l, during the operation thereof, rock the arms 35 and the shafts 34 forthe purpose of moving the track SWiChQ 3'3 to the switching position shown in Figures 2 and 3. The non-switching position of a switch is shown in Figure 1. While the track switches 33 are in the positions indicated in Figure 1, the pivot extensions 2| at the rear of the respective trays can pass along the lower tracks I5 beneath the lower ends of the arcuate tracks 32. When the track switches 33 are in the position shown in Figures 2 and 3 they formarcuate eX- tensions of the tracks 32 and thus cooperate with the latter and with the transfer arms in guiding the forward unpivoted ends of the respective trays from the tracks 32 onto the lower tracks I5, as

suggested by tray 20c in Figure 2.' Thecams 31 l are arranged to Voperate the track switches 33 in synchronism with the arcuate movements of the vtrays from one horizontal run of the conveyer to the other regardless of the direction of movement of the conveyer. f

For the purpose of causing the follower` arms 35 to tend to swing to the right or clockwisey as viewed in Figure2, and thereby retain the cam- 1 in properly timed relation with respect to the movement of the pivotedends of-a tray beneath the arcuate tracks 32, theswitches would Vobstruct 1 the horizontal movement of the pivoted ends of the tray and cause damage to the apparatus. "To

avoid such damage the track switches shown in Y the present application are designed to prevent such damage from the cause mentioned and, as will be seen in the drawings, the rearportion'sl of the track switches 33 are provided with inclined cam surfaces 4| which, in the event the track switches fail to vmove out of the bridging relation between the lower tracks l5 and the lower ends of the arcuate tracks 32, will be engaged by the f pivotal extensions 2| of an approaching tray', thereby forcing the-track switches 33 downwardly in a clockwise direction. Forthe purpose of preventing the cam surfaces 4| of the track switches from effecting elevation of the chains VI3 as the pivotal extensions 2| engage said surfacesV 4|, guard rails 42 are provided, as shown in Figures 2 and 3, which prevent such upward deection of the pivots 2| and the associated links of the chains. The guard rails 42 extend inwardly over the adjacent `portions of the lower runs of the chains |3 and are shown mounted on the sliding structures A in which the shafts I2, 25 and 34 are journalled and which structures are biased by springs B for movement to the right for tensioning the chains I3 while accommodating expansion and contraction and wear thereof, as disclosed in the above mentioned patent.

It will be seen that by means of the present of the conveyer mechanism. Y In the event the conveyer is being operated accesso son 'of the shafts 34 'thereof-freezing in their bear- Y ifi-gs, `the switches would tend to elevate the pivdtvd end-of stray as the pfvdt' members therecf'rijgagethe usersurfsces ort-ne switehesfa'a Fdfthe purpose ofV causing the pivot members '21 tfiiferce tneswitches `out offenen eie'vated or bridging" positions under 'such conditions,` guard rails 4,4, arepositioned above the lower `run `of the' Achains |13 and to the left of the arcuate tracks 32 as viewed in Figure 2. These rails 44 may be secured to the respective oven walls and prevent upward deflection of the chains from theA lower tracks l5, and hence, should the switches remain in the elevated position as the pivots 2l approach them in moving to the right, the switches will be cammed out of the elevated position by said pivot members and the pivoted ends of the tray will thus not engage the lower` ends of the arcuate tracks 32 but will pass through'the switch spaces beneath the arcuate tracks 32. v

It will therefore be seen that a safety switch mechanism has been provided whereby, in event `oi. failure of the switchesto move in proper sequence out of obstructing position to permit horizontal passage along the lower tracks of` the laterally extending pivot members 2l of the trays, `said members 2l, in approaching said switches, will cam them out of such obstructing positions.

At the forward end of the conveyer the structure is `similar to that described in the above `mentioned patent and comprises transfer arms 45,

each mountedon suitable shafts 46, driven from shafts I9 by means of chains 41 passing over sprockets 48 and 49. Arcuate track members 50 constitute in eifect forward extensions of the lower tracks l5. As a tray, such as tray d in Figure 1, in moving to the left approaches the position where the rear pivotal extension 2l thereof begins to move arcuately about the sprockets Il, the transfer arms 45 will have engaged the rollers 22 at the forward ends of the tray and incooperation with the arcuate tracks 50 will retain the tray in horizontal relation during the subsequent arcuate movement, as indicated by tray 20e, in Figure l. During the transfer arcuately from one horizontal run of the conveyer to the other the mechanism described operates simi-` larly pegardless of the direction of rotation of the conveyer, that is, whether the trays in the upper run of the conveyer move to the right or to the left as viewed in Figure l. Successive trays, in moving to the transfer position at either spaces to provide extensions of said arcuate tracks for guiding tray portions across said spaces, means for moving said switches to non-switching position, and means on said switches cooperable with other portions or tnetfays 'for moving issie switches out of switching position upon failure of said means to move said switches tonen-switching position as said other tray portions approach said' spaces.

2. In a tray conveyer mechanism provided with upper and lower tracks, arcuate tracks disposed Vbetween said upper and lower tracks and spaced from the latter, track switches providing extensions cf 'said arcuate tracks; Vfor bridging the spaces-between said arcuate tracks andlower trackslfordirecting tray portions across said spaces," means `for moving" said switches to` said bridging positions, and means engageable by other portions of the trays for moving said switches out of said bridging positions.

3. In a tray conveyer mechanism provided with upper and lower tracks, arcuate tracks disposed between said upper and lower tracks and spaced from the latter, track switches providing extensions of said arcuate tracks for bridging the spaces between said arcuate tracks and lower tracks for directing tray portions across said spaces, means for moving said switches to said bridging positions, and cam means carried by said switches and disposed by the latter in the path of other portions of the trays when the switches are in bridging position for engagement by said other tray portions for moving the switches out of bridging position as said tray portions approach said spaces.

4. 4In a tray conveyer mechanism comprising `tracks being spaced from said lower tracks to provide passages through which the pivot members of successive trays are arranged to pass in moving along said lower horizontal run, track switch members movable into saidspaces to bridge said spaces for cooperation with said rotary members in moving said unpivoted portions of the trays across said spaces, cam means for moving said switches intermittently into said bridging positions in timed relation with respect to the arcuate movements of the successive trays, and means adapted to be operated by said pivot members of said trays to moving the switch members out of said bridging positions as the respective pivot members approach said spaces.

5. In a tray conveyer mechanism comprising endless chains, trays provided with laterally extending pivotal members secured to said chains, upper and lower tracks for supporting said chains, arcuate tracks disposed between said upper and lower tracks and spaced from the latter, track switches providing extensions of said arcuate tracks for bridging the spaces between said arcuate tracks and lower tracks for directing tray portions across said spaces, cam means for moving said switches to said bridging positions, biasing means for moving said switches out of said bridging positions alternately with respect to the movements thereof by said cam means, and means on said switch` lmembers engageable by the pivotal members of a tray approaching said spaces for moving said switches out of switching positions inthe event said switches'are not so moved by said biasing means. Y

V6. In a, tray conveyer mechanism comprising endless chains, trays provided with laterally extending pivotal members secured to said chains, upper and lower tracks for supporting said chains, arcuate tracks disposed between said upper and lower tracks and spaced from the latter, track switches providing extensions of said arcuate rtracks for 4bridging the spaces between said arcuswitches to said bridging positions, biasing means portions. H

*,for moving saidv switches out of said bridging positions alternately with respect to the movements l ,thereof by said cam means, cam portions on said switch members engageable by the pivotal members of a tray approachingsaid spaces for moving said switches out of switching positions in the event said switches are not so moved'by said bias'- ing means, and means for constraining said pivot.- a1 members against deection Afrom` the normal paths of movementby engagement with said cam JOHN RNALBACHI

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