SHUTTER PIECE AND SHUTTER SET FOR MOLDING FOOD DOUGH

A shutter piece includes an upper portion and a lower portion of an opening-side surface. The upper portion has an upper edge and an intermediate edge, and is configured to close a front end of the intermediate edge after a front end of the upper edge is closed when the plurality of shutter pieces is swung to close the opening. The lower portion includes a protruding edge disposed between the upper edge and the intermediate edge in the plan view. The shutter piece is configured to define a ceiling space for receiving the peripheral portion of the outer skin material when the front end of the upper edge is closed. The shutter piece is configured to reduce the upper space while the outer skin material in the ceiling space is held by the lower portion until the front end of the intermediate edge is closed.

TECHNICAL FIELD

The present invention relates to a shutter set used to envelop an inner material with a flat food dough, and a shutter piece constituting the shutter set.

BACKGROUND ART

Patent document 1 is directed to an enveloping and forming method and apparatus for a food product, and discloses that a peripheral edge portion of an outer skin material is attached and sealed to itself to allow an inner material to be enveloped by a closing operation of a shutter set constituted by combining a plurality of shutter pieces. A side surface of each shutter piece has a front edge which closes earlier by a closing operation of the shutter set, a base edge which closes later than the front edge, and a slope surface between the front edge and the base edge.

In this forming method, the peripheral edge portion of the outer skin material is attached and sealed to itself by the base edge in a state that the front edges or the slope surfaces of the adjacent shutter pieces are closed, so that the outer skin material can envelop the inner material without protruding from the shutter set (Patent Document 1).

Patent Document 2 discloses a shutter piece, a shutter set, a shutter device and a forming apparatus used for forming an enveloped food product. The shutter piece has a first side surface for attaching and sealing the peripheral edge portion of the outer skin material to itself at a position above the inner skin material, and a second side surface which is located below the first side surface and contacts the outer skin material earlier than the first side surface to gather the outer skin material toward a position above a center of the inner skin material.

In the shutter piece configured in this way, the second side surface contacts the outer skin material earlier than the first side surface which is for attaching and sealing the outer skin material to itself. Since the second side surface is located lower than the first side surface, the outer skin material near the inner material is concentratively gathered and stretched, so that a gathering effect can be enhanced. Then, the outer skin material gathered above the inner material is attached and sealed to itself by the first side surface.

In this shutter set, the closing operation is stopped when the front edge of the first side surface of each shutter piece is at a center of an opening of the shutter set, to close the opening. At this time, a recessed space is formed at the center of the lower surface of the shutter set (Patent Document 2).

Further, at a bottom of the shutter piece described in Patent Documents 1 and 2, an intersection angle between the side surface defining the opening and a bottom surface of the shutter piece is about a right angle.

PRIOR ART PUBLICATION

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

In the shutter set described in the Patent Document 1, the outer skin material does not protrude from an upper surface of the shutter set during the closing operation. However, since the base edge is perpendicular to the upper and lower surfaces of the shutter piece, the outer skin material is easy to move downward, so that the sealing of the outer skin material may be insufficient.

In the shutter set described in Patent Document 2, when the opening of the shutter set is closed, the outer skin material may be protruded onto the upper surface of the shutter set. To avoid this, stopping the closing operation before the opening of the shutter set is closed may allow the outer skin material to be remained more than necessary at the top of the enveloped food product and protruded so that an appearance of the enveloped food product may be deteriorated. Further, the sealing of the outer skin material may be insufficient.

Further, when the opening of the shutter set is closed, the outer skin material may be stored in a recessed space at the lower surface of the shutter set. However, the physical properties of the outer skin material may cause the outer skin material to be insufficiently sealed.

Further, when the shutter set gathers the outer skin material toward the center, the bottom of the shutter piece may roughen the surface of the outer skin material.

The present invention is for solving the above-stated problem, and has a first object to provide a shutter piece, a shutter set, a shutter device and a forming apparatus which are capable of surely attaching and sealing an outer skin material to itself when an enveloped food is formed.

Further, the present invention has an object to provide a shutter piece, a shutter set, a shutter device, and a forming apparatus which are capable of preventing a surface of an outer skin material from being rough when an enveloped food is formed.

Means for Solving the Problem

The present invention is directed to a shutter piece of a shutter set used in a shutter device for enveloping an inner material by a disk-like outer skin material, a center of which the inner material is supplied onto, to form a enveloped food product, the shutter piece including a first side surface for attaching and sealing a peripheral edge portion of the outer skin material to itself above the inner material, and a second side surface located below the first side surface for contacting the outer skin material before the first side surface to gather the outer skin material toward a position above a center of the inner material, wherein, in the plan view, the first side surface includes a convex upper edge extending from a base end to a front end, and a convex lower edge extending from a base end to a front end at a position recessed from the first side surface, and wherein in the plan view, the second side surface includes a convex protruding edge extending from a base end to a front end between the upper edge and the lower edge, and a horizontal portion.

For example, the shutter piece may further include an intermediate side surface between the first side surface and the second side surface, and the intermediate side surface may vertically have the same contour as the lower edge of the first side surface.

For example, the protruding edge may be formed as a peripheral edge of the horizontal portion.

For example, the protruding edge may be formed as a peripheral edge of an upper slope portion extending obliquely downward from the horizontal portion to protrude from the horizontal portion.

For example, the second side surface may include a vertical surface vertically having the same contour as the protruding edge.

For example, in the plan view, a width between the lower edge and the protruding edge of the first side surface may became smaller from the base end toward the front end of the second side surface.

For example, the second side surface may further include a lower slope portion extending obliquely downward from the protruding edge to be recessed from the protruding edge.

For example, the shutter piece may further include a front-end surface which is located below the first side surface and closer to the base end than the front edge of the first side surface and intersects a front portion of the second side surface.

For example, the shutter piece may further include a lower horizontal surface extending from the upper end of the front surface toward the front portion of the shutter piece.

For example, the shutter piece may form a portion of a ceiling space by at least the first side surface, the second side surface, and the front surface when the shutter unit is closed.

For example, the shutter piece may form a portion of a ceiling space by the second side surface, the front surface, and the lower horizontal surface when the shutter unit is in a fully-closed state.

For example, a shutter set may be formed by combining the shutter pieces.

For example, a shutter device may include the shutter set.

For example, a forming apparatus may include the shutter device.

Effects of the Invention

The shutter piece, the shutter set, the shutter device, and the forming apparatus according to the present invention allows the outer skin material to be surely attached and sealed to itself. Further, the shutter piece, the shutter set, the shutter device, and the forming apparatus according to the present invention allows a surface of the outer skin material to be prevented from being roughened when the outer skin material is attached and sealed to itself.

DESCRIPTION OF EMBODIMENTS

Referring toFIGS.1-11, a shutter piece and a shutter set according to a first embodiment of the present invention will be explained.

A shutter device23shown inFIG.1is a part of a forming apparatus1described later, and includes a base plate23a, a hole plate23b, a shutter set2constituted by circumferentially arranging eight shutter pieces3according to the first embodiment of the present invention, and a driving mechanism1afor driving the shutter pieces3. The shutter set2is configured to move between a fully-closed state (See, for example,FIG.10C) and an opened state (See, for example,FIG.10A) defining an opening5by synchronously swinging the eight shutter pieces3. Since the drive mechanism1ais, for example, a link mechanism connected to a drive motor (not shown) installed in the forming apparatus1, and a detailed description thereof is omitted since it is conventionally known.

As shown inFIGS.4and5, the shutter piece3has an upper surface3a, a lower surface3b, and side surfaces7,9,11located between the upper surface3aand the lower surface3b. The side surfaces7,9,11include an opening-side surface7defining the opening5, an abutting-side surface9defining front-end edges13c,14ctogether with the opening-side surface7, and the other side surfaces11.

The lower surface3band other side surfaces11are provided with drive attachments3dattached to the drive mechanism1a, and the drive attachments3dare, for example, recesses and holes, which detailed description is omitted since they are conventionally known.

The opening-side surface7has an upper portion13, a lower portion15located below the upper portion13, and an intermediate portion14located between the upper portion13and the lower portion15.

The upper portion13is mainly defined by an upper edge13a, an intermediate edge14a, and a front-end edge13c, and extends obliquely downward from the upper edge13atoward the intermediate edge14a(intermediate portion14) to be recessed from the upper edge13a. In the plan view, the upper edge13ais convex and arcuate, and extends from a base end13bto a front end13e(seeFIGS.2and3). In the plan view, the intermediate edge14ais convex and arcuate, and extends from a base end14bto a front-end14e. The front-end edge13cextends from the front end (upper end)13eof the upper edge13ato the front end (lower end)14eof the intermediate edge14aand is vertically inclined. The position of the front-end edge13cis preferably determined to pass through a center5aof the opening5of the shutter set2when the shutter piece3is swung (seeFIGS.10B and10C).

A front-side portion of the intermediate portion14is mainly defined by the intermediate edge14a, a lower intermediate edge14d(lower end), and a front-end edge14c, is a single surface connecting the intermediate edge14a(lower edge of the upper portion13) to the lower intermediate edge14d(upper end of the lower portion15), and vertically has the same contour. In the plan view, the lower intermediate edge14dis convex and arcuate, and extends from a base end to a front end14g. The front-end edge14cextends linearly in the vertical direction from the front-end14e(upper end, i.e., lower end of the front-end edge13c) of the intermediate edge14ato the front end14g(lower end) of the lower intermediate edge14d. The position of the front-end edge14cis preferably determined to pass through the center5aof the opening5of the shutter set2when the shutter piece3is swung (seeFIG.10C). In the plan view, a width between the upper edge13aand the intermediate edge14abecomes wider from the base end14bto the front end14e(the front-end edge14c) (seeFIGS.2and3).

In the plan view as shown inFIG.3, a front-side portion of the lower portion15is disposed to be recessed from the upper edge13a, but to be protruded from the intermediate edge14aand the lower intermediate edge14d(the intermediate portion14), and has a protruding edge15awhich is convex and arcuate. The protruding edge15aextends from a base end15bto a front end15e. In the plan view, the front end15eand the base end15bare recessed toward the abutting-side surface9from the upper edge13aand protruded toward the opening5from the intermediate edge14a(lower intermediate edge14d).

Specifically, as shown inFIGS.4and5, the front-side portion of the lower portion15includes three surfaces, namely, a horizontal portion60, an upper slope portion62, and a lower slope portion64. The horizontal portion60is an upward surface disposed along the lower intermediate edge14d(intermediate portion14) and horizontally extends to protrude from the lower intermediate edge14d(intermediate portion14). A width of the horizontal portion60horizontally protruding from the intermediate portion14becomes smaller from the base end15btoward the front end15e. The upper slope portion62extends obliquely downward to protrude from the horizontal portion60. The lower slope portion64extends obliquely downward to the lower edge15d(lower surface3b) to be recessed from the upper slope portion62. The convex protruding edge15ais a peripheral edge of the lower portion15and is defined by a boundary line between the upper slope portion62and the lower slope portion64. In the plan view, a width between the protruding edge15aand the intermediate edge14abecomes smaller from the base end15btoward the front end15e(seeFIGS.2and3).

The upper slope portion62is preferably an inclined surface extending obliquely upward from the protruding edge15a, and a profile of a vertical section of the inclined surface may be a straight line, a convex or concave curved line, or a combination thereof. In this embodiment, the profile of the vertical section of the inclined surface of the upper slope portion62is a straight line. Further, the lower slope portion64is preferably an inclined surface extending obliquely downward from the protruding edge15a, and a profile of a vertical section of the inclined surface may be a straight line, a convex curved line, or a combination thereof. In this embodiment, the profile of the vertical section of the inclined surface of the lower slope portion64is a convex curved line. In the plan view, the lower edge15dwhere the lower slope portion64(lower portion15) intersects the lower surface3bextends in a convex and arcuate way (seeFIG.3).

As shown inFIG.5, the lower portion15further has a front edge62con a front side of the upper slope portion62, and a front edge64con a front side of the lower slope portion64. The front end15eof the convex protruding edge15ais an intersection of the front edge62cof the upper slope portion62and the front edge64cof the lower slope portion64.

Further, as shown inFIG.3, in the plan view, the front edge62cof the upper slope portion62and the front edge64cof the lower slope portion64are not located at the front-end edge13cof the upper portion13and the front-end edge14cof the intermediate portion14, i.e., they are offset toward the base end15bof the protruding edge15aso that they do not pass through the center5aof the opening5.

As shown inFIG.5, the abutting-side surface9has an upper portion17, an intermediate portion18, and a lower portion19. Further, the lower portion19includes a horizontal portion70, an upper slope portion72, and a lower slope portion74.

As shown inFIGS.2-5, the upper portion17is mainly defined by an upper edge17a, an intermediate edge18a, and the front-end edge13cwhich is common to the upper portion13of the opening-side surface7. The intermediate portion18is mainly defined by the intermediate edge18a, a lower intermediate edge18d, and the front-end edge14cwhich is common to the intermediate portion14of the opening-side surface7(seeFIG.7). The horizontal portion70of the lower portion19is a downward surface horizontally extending to be recessed from the lower intermediate edge18d. The upper slope portion72extends obliquely downward to be recessed from the horizontal portion70and has a front edge72con its front side. The lower slope portion74extends obliquely downward to a lower edge19d(lower surface3b) to protrude from the upper slope portion72and has a front edge74con its front side. A recessed edge19abetween the upper slope portion72and the lower slope portion74extends from a base end19bto a front end19e, and the front end19eis an intersection of the front edge72cof the upper slope portion72and the front edge74cof the lower slope portion74(seeFIGS.3and9).

Preferably, the front-end edge13c, the front-end edge14c, and the front edges72c,74calways abut the upper portion13, the intermediate portion14, and the upper and lower slope portions62,64of the lower portion15of the opening-side surface7of the adjacent shutter piece3, respectively, without substantially causing any clearance when the shutter piece3is swung.

Further, a front portion of the lower intermediate edge14dof the intermediate portion14of the opening-side surface7is preferably formed so that when the front portion of the lower intermediate edge14dis located on the horizontal portion60of the lower portion15of the opening-side surface7in the adjacent shutter piece3, the front portion always abuts the horizontal portion60without substantially causing any clearance (seeFIGS.4and5).

In the following explanation, states when the front end13e(upper end) and the front-end14e(lower end) of the front-end edge13cof the upper portion13of the opening-side surface7are located at the center5aof the opening5are referred to as a “starting closing state” and a “fully-closed state” of the shutter set, respectively. In this embodiment, in the fully-closed state, the front-end edge14cof the intermediate portion14of the opening-side surface7is also located at the center5aof the opening5.

The upper portion17, the intermediate portion18and the lower portion19of the abutting-side surface9are preferably formed in a concave shape to abut the upper portion13, the intermediate portion14and the lower portion15of the opening-side surface7of the adjacent shutter piece, respectively, when the shutter set2is in the fully-closed state.

Specifically, the upper edge13aand the intermediate edge14aof the upper portion13of the opening-side surface7can abut the upper edge17aand the intermediate edge18aof the upper portion17of the abutting-side surface9of the adjacent shutter piece3, respectively (seeFIG.10C). The intermediate edge14aand the lower intermediate edge14dof the intermediate portion14of the opening-side surface7can abut the intermediate edge18aand the lower intermediate edge18dof the intermediate portion18of the abutting-side surface9of the adjacent shutter piece3, respectively. The protruding edge15aand the lower edge15dof the lower portion15of the opening-side surface7can abut the recessed edge19aand the lower edge19dof the lower portion19of the abutting-side surface9of the adjacent shutter piece3, respectively (seeFIG.8). Namely, in the plan view, each of the upper edge17a, the intermediate edge18a, the lower intermediate edge18d, the recessed edge19a, and the lower edge19dof the abutting-side surface9is formed to be concave and arcuate.

Further, in a plan view, the front edge72cof the upper slope portion72and the front edge74cof the lower slope portion74are not located at the front-end edge13cof the upper portion17and the front-end edge14cof the intermediate portion18, namely, they are offset toward the base edge19bof the recessed edge19aso that they do not pass through the center5aof the opening5.

The shutter piece3has a front-end surface80below the front-end edge14cwhich is offset closer to the base-end14bthan the front-end edge14c. The front-end surface80is a combination of an upper front-end surface82and a lower front-end surface84(seeFIG.7). The upper front-end surface82is a substantially quadrangular surface with opposite sides, namely, the front edge62cof the upper slope portion62of the opening-side surface7and the front edge72cof the upper slope portion72of the abutting-side surface9. Further, the lower front-end surface84is a substantially quadrangular surface with opposite sides, namely, the front edge64cof the lower slope portion64of the opening-side surface7and the front edge74cof the lower slope portion74of the abutting-side surface9. The front-end surface80is formed so as to intersect the lower portions15,19on the front-end side of the lower portions15,19. Further, the shutter piece3has a downward horizontal surface extending from an upper end of the front-end surface80toward the front-end side of the shutter piece3. When the shutter piece3is viewed from its bottom, a planar intermediate lower surface3f, which includes this horizontal surface and a horizontal portion70of the lower portion19, is formed on the front side of the shutter piece3(seeFIGS.5and7).

As shown inFIGS.6,7and10B, locating the front end13eof the upper edge13aof the opening-side surface7of the shutter piece3at the center5aof the opening5causes a state in which the opening5of the shutter set2is closed by the front ends13e(the starting closing state). At this time, the front-end edges13c,14c, the front edges72c,74c, and the front portion of the lower intermediate edge14dof the shutter piece3abut the upper portion13, the intermediate portion14, and the lower portion15of the opening-side surface7of the adjacent shutter piece3, respectively. Thus, on the opening-side surface7of each shutter piece3, a ceiling space S with concaveness and convexness is formed and surrounded by the inclined upper portion13, the vertically-extending intermediate portion14, the lower portion15protruding toward the opening5, the front-end surface80offset from the front end toward the base end of the shutter piece3, and the lower portion19and the intermediate lower surface3fcontinuous to the front-end surface80. The ceiling space S is defined in a top-down order by a first space S1with a substantially octagonal pyramid surrounded by the eight upper portions13, a second space S2with a substantially octagonal prism surrounded by the eight intermediate portions14, and the remaining third space S3(seeFIG.19).

While the shutter set2is moved from the starting closing state to the fully-closed state shown inFIGS.8,9and10C, the ceiling space S is entirely reduced. Specifically, a height and a diameter of the first space S1are reduced, and a diameter of the second space S2is reduced.

As a result, when the shutter set2reaches the fully-closed state, the first space S1and the second space S2have not existed, so that the ceiling space S is defined only by the reduced third space S3(seeFIG.21). Specifically, a ceiling of the third space S3is defined by the intermediate lower surfaces3fon the front side of the eight shutter pieces3, while the remaining of the third space S3is surrounded by the eight front-end surfaces80offset from the front-end edges13c,14ctoward the base side, and the lower portion19continuous to the front-end surface80.

Next, referring toFIGS.12and16, an exemplary forming apparatus using a shutter device including a shutter set will be schematically explained.

The forming apparatus1is used for forming an enveloped food product P in which an inner material F is enveloped by an outer skin material D. Regarding the forming apparatus1, portions relating to the present invention will be mainly explained, while explanations of the other portions conventionally known will be omitted.

The forming apparatus1includes a supply conveyor device21for supplying a disk-like outer skin material D on which an inner material F is deposited, a shutter device23located below the supply conveyor device21, a press device25located above the supply conveyor device21, and a support device27located below the shutter device23, which devices are controlled by a controller (not shown).

The supply conveyor device21includes a front-end portion21awhich is extensible and retractable between an extended position and a standby position.

The shutter device23includes a base plate23a, a hole plate (placing member)23bfor supporting the outer skin material D supplied from the supply conveyor device21, and a shutter set2swinging and sliding on the hole plate23b. The hole plate23bhas a circular central opening23c. A size of a diameter and a thickness (height) of the central opening23care appropriately selected according to the enveloped food product P to be formed.

The press device25includes a press member25aand a raising and lowering device25bfor raising and lowering the press member25a. The press member25ais in a cup shape with a downward opening25cand has an annular peripheral wall25dand a ceiling part25edisposed on an upper part of the peripheral wall25d. In the present embodiment, the raising and lowering device25bincludes a piston rod25fmoving upward and downward, and the piston rod25fhas a through hole25gfor supplying compressed air downward. The ceiling part25ehas a through hole25hcommunicating with the through hole25gof the piston rod25f.

The support device27is defined by a belt conveyor and allowed to be raised and lowered.

Next, referring toFIGS.12-22, an operation of the forming apparatus1will be explained.

As shown inFIG.12, the disk-like outer skin material D on which the inner material F is deposited is conveyed by the supply conveyor device21to a position where a center of the outer skin material D corresponds to the center5aof the opening5of the shutter set2, namely, a center of the opening23cof the hole plate23b. The front-end portion21aof the supply conveyor device21is in the extended position.

As shown inFIG.13, the front-end portion21aof the supply conveyor device21is retracted from the extended position to the standby position, so that the outer skin material D and the inner material F are placed onto the hole plate23b.

As shown inFIG.14, the shutter device23is actuated to move the shutter set2toward the closed state. On the opening-side surface7of the shutter piece3, the protruding edge15aof the lower portion15is allowed to contact the peripheral edge portion DE of the outer skin material D, and then, the upper slope portion62and the horizontal portion60are allowed to get under a lower surface of the peripheral edge DE. Further, after the intermediate portion14is allowed to contact a peripheral edge of the outer skin material D, a closing action of the shutter set2is temporarily stopped. This allows an amount of the peripheral edge portion DE required for a sealing operation to evenly remain on the hole plate23b. Further, a portion of the outer skin material D around its center is pushed from the peripheral edge by the shutter set2and recessed into the opening23cof the hole plate23bdue to the own weights of the outer skin material D and the inner material F.

As shown inFIG.15, the press member25aof the press device25is lowered and stopped at an appropriate lowered position depending on, for example, a thickness and hardness of the outer skin material D. The peripheral edge portion DE of the outer skin material D is pressed by the annular peripheral wall25dof the press member25aagainst the hole plate23bto seal an inner space defined between the outer skin material D and the press member25a.

As shown inFIG.16, by supplying compressed air from the through hole25hinto the inner space, the outer skin material D is expanded downward inside of the opening23cto form a bowl-like shape. A bottom portion of the downward expanded outer skin material D is supported by the support device27to prevent the outer skin material D from being deformed more than required and stabilize a shape of the outer skin material D. At that time, a position of the support device27allows a position of a head of the inner material F to be determined relative to an upper surface of the hole plate23b. The position of the head of the inner material F is preferably the same as or lower than the hole plate23b.

As shown inFIG.17, the press member25ais raised. As shown inFIG.18, the shutter set2is moved toward the closed state again. The lower portion15of the shutter piece3allows the outer skin material D near the inner material F to be concentrically gathered and stretched toward a position above a center of the inner material F. Since the horizontal portion60is configured to protrude from the intermediate portion14toward the opening5, a force for holding the outer skin material D can be enhanced so that the gathering effect can be further enhanced. Further, since the lower slope portion64of the lower portion15is formed to be inclined toward the abutting side surface9in a fan-like shape, roughening (scratching) on the surface of the outer skin material D can be prevented. In the present embodiment, since the profile of the vertical section of the inclined surface of the lower slope portion64is formed of a convex curved surface, the effect of preventing the roughening of the surface can be further enhanced.

The closing action of the shutter set2is forwarded, and the inner material F is enveloped to be sealed by the outer skin material D surrounded by the eight lower portions15at a position above the inner material F. As shown inFIG.19, the closing action of the shutter set2is further forwarded so that the front end13eis located at the center5a, and this allows the opening5of the shutter set2to be closed to form the ceiling space S. As a result, it is possible to prevent the outer skin material D from leaking onto the upper surface3aof the shutter piece3, namely, onto the upper surface of the shutter set2.

As shown inFIG.20, as the closing action of the shutter set2is forwarded, a volume of the ceiling space S is reduced. Since a diameter of the third space S3of the ceiling space S is smaller than a diameter of the second space S2located above the third space S3, the third space S3assumes a role of a squeezing valve for the outer skin material D pushed out from an inside of the ceiling space S. As a result, the outer skin material D remaining inside of the ceiling space S is subject to a strong pressure from the shutter set2, and at the same time, pushed out through the gradually-reduced third space S3, so that the peripheral edge portion DE of the outer skin material D is firmly attached and sealed to itself.

Further, a width of the lower portion15horizontally protruding from the intermediate portion14becomes smaller from the base end15btoward the front end15e. Thus, as the ceiling space S is gradually reduced, the protruding width of the lower portion15becomes smaller, so that the third space S3is not closed and the opening can be maintained.

As shown inFIG.21, the shutter set2is moved to the fully-closed state, the closing action of the shutter set (unit)2is stopped, and the attaching and sealing operation of the outer skin material D due to the shutter set (unit)2is finished. At this time, the ceiling space S exists only at the reduced third space S3, as explained above. Alternatively, if the outer skin material D can be attached and sealed to itself, the shutter set2may not be moved to the fully-closed state. In this case, the ceiling space S is formed by the first space S1, the second space S2, and the third space S3, and the outer skin material D is stored in the ceiling space S, so that an amount of the outer skin material D gathered to an upper central portion of the enveloped food material P increases. Thus, a top of the enveloped food product P is prevented from being recessed because when the outer skin material D in the upper central portion of the enveloped food material P is stretched toward a periphery to its elasticity, the stored outer skin material D is extended (see FIG.20).

As shown inFIG.22, the shutter set2is moved toward the opened state, the outer skin material D of the head of the enveloped food product P is released, and the support device27on which the enveloped food product P is deposited is lowered.

Next, referring toFIGS.23-26, a shutter piece and a shutter set according to a second embodiment of the present invention will be explained.

A shutter piece103of the second embodiment according to the present invention has a structure which is similar to that of the shutter piece3of the first embodiment, but is different mainly from the lower portions15,19and the front-end surface80of the shutter piece3. Components of the shutter piece103according to the second embodiment, which are similar to those of the shutter piece3according to the first embodiment, have the same reference numerals as those of the shutter piece3, and their detailed explanation is omitted.

An opening-side surface107of the shutter piece103includes the upper portion13, the intermediate portion14, and a lower portion115.

In the plan view as shown inFIG.24, a front-side portion of the lower portion115is disposed to be recessed from the upper edge13a, but to be protruded from the intermediate edge14aand the lower intermediate edge14d(the intermediate portion14), and has a protruding edge115awhich is convex and arcuate. The protruding edge115aextends from a base end115bto a front end115e. In the plan view, the protruding edge115ais located between the upper edge13aand the intermediate edge14a(lower intermediate edge14d). In the plan view, the front end115eand the base end115bare recessed toward the abutting-side surface9from the upper edge13aand protruded toward the opening5from the intermediate edge14a(lower intermediate edge14d).

Specifically, as shown inFIGS.25and26, the front-side portion of the lower portion115includes three surfaces, namely, a horizontal portion160, a vertical portion162, and a lower slope portion164. The horizontal portion160is an upward surface disposed along the lower intermediate edge14d(intermediate portion14) and horizontally extends to protrude from the lower intermediate edge14d(intermediate portion14). A width of the lower portion115horizontally protruding from the intermediate portion14becomes smaller from the base end115btoward the front end115e. The vertical portion162downwardly extends from and orthogonal to the horizontal portion160. The lower slope portion164extends obliquely downward to the lower edge15d(lower surface3b) to be recessed from the vertical portion162. The convex protruding edge115ais a peripheral edge of the lower portion115and is defined by a boundary line between the horizontal portion160and the vertical portion162. In the plan view, a width between the protruding edge115aand the intermediate edge14abecomes smaller from the base end115btoward the front end115e(seeFIGS.23and24).

The vertical portion162is preferably a curved surface extending downward from the protruding edge115ato a lower protruding edge115d, and vertically has the same contour. The lower protruding edge115dextends from a base end115fto a front end115g. Further, the lower slope portion164is preferably an inclined surface extending obliquely downward from the lower protruding edge115dof the vertical portion162, and a profile of a vertical section of this inclined surface may be a straight line, a convex curved line, or a combination thereof. In this embodiment, the profile of the vertical section of the inclined surface of the lower slope portion64is a convex curved line. In the plan view, the lower edge15dwhere the lower slope portion164intersects the lower surface3bextends in a convex and arcuate way (seeFIG.24).

As shown inFIG.26, the lower portion115further has a front edge162con a front side of the vertical portion162and a front edge164con a front side of the lower slope portion164. The front end115gof the above-stated lower protruding edge115dis an intersection of the front edge162cof the vertical portion162and the front edge164cof the lower slope portion164.

As shown inFIG.24, in the plan view, the front edge162cof the vertical portion162and the front edge164cof the lower slope portion164are not located at the front-end edge13cof the upper portion13and the front-end edge14cof the intermediate portion14, namely, they are offset toward the base end115fof the protruding edge115aso that they do not pass through the center5aof the opening5.

As shown inFIG.26, an abutting-side surface109of the shutter piece103has the upper portion17, the intermediate portion18, and a lower portion119. Further, the lower portion119includes a horizontal portion170, a vertical portion172, and a lower slope portion174.

As shown inFIGS.23-26, the horizontal portion170of the lower portion115is a downward surface that horizontally extends to be recessed from the lower intermediate edge18d. The vertical portion172extends downward from and orthogonal to the horizontal portion170and has a front edge172con its front side. The lower slope portion174extends obliquely downward to the lower edge19d(lower face3b) to protrude from the vertical portion172and has a front edge174con its front side. A recessed edge119abetween the horizontal portion170and the vertical portion172extends from a base end119bto a front end119e, and the front end119eis an intersection of the front edge170cof the horizontal portion170and the front edge172cof the vertical portion172. A lower recessed edge119dbetween the vertical portion172and the lower slope portion174extends from a base end119fto a front end119g, and the front end119gis an intersection of the front edge172cof the vertical portion172and the front edge174cof the lower slope portion174.

Preferably, the front-end edge13c, the front-end edge14c, and the front edges172c,174care formed to always abut the upper portion13, the intermediate portion14, and the vertical and lower slope portions162,164of the lower portion115of the opening-side surface107of the adjacent shutter piece103, respectively, without substantially causing any clearance when the shutter piece103is swung. Namely, each of the upper edge17a, the intermediate edge18a, the lower intermediate edge118d, the recessed edge119a, the lower recessed edge119d, and the lower edge19dof the abutting side surface109is formed to be concave and arcuate in the plan view.

Further, a front portion of the lower intermediate edge14dof the intermediate portion14of the opening-side surface107is preferably formed so that when the front portion of the lower intermediate edge14dis located on the horizontal portion160of the lower portion115of the opening-side surface107in the adjacent shutter piece103, the front portion always abuts the horizontal portion160without substantially causing any clearance (seeFIGS.25and26).

The upper portion17, the intermediate portion18and the lower portion119of the abutting-side surface109are preferably formed in a concave shape to abut the upper portion13, the intermediate portion14and the lower portion115of the opening-side surface107of the adjacent shutter piece, respectively, when the shutter set102is in the fully-closed state.

Specifically, the upper edge13aand the intermediate edge14aof the upper portion13of the opening-side surface107can abut the upper edge17aand the intermediate edge18aof the upper portion17of the abutting-side surface109of the adjacent shutter piece103, respectively. The intermediate edge14aand the lower intermediate edge14dof the intermediate portion14of the opening-side surface107can abut the intermediate edge18aand the lower intermediate edge18dof the abutting-side surface109of the adjacent shutter piece103, respectively. The protruding edge115aand the lower protruding edge115dof the vertical portion162and the lower edge15dof the lower slope portion164of the lower portion115of the opening-side surface107can abut the recessed edge119aand the lower recessed edge119dof the vertical portion172and the lower edge19dof the lower slope portion164of the abutting-side surface109of the adjacent shutter piece103, respectively. Namely, in the plan view, each of the upper edge17a, the intermediate edge18a, the lower intermediate edge18d, the recessed edge119a, the lower recessed edge119d, and the lower edge19dof the abutting-side surface109is formed to be concave and arcuate.

Further, in a plan view, the front edge172cof the vertical portion172and the front edge174cof the lower slope portion174are not located at the front-end edge13cof the upper portion17and the front-end edge14cof the intermediate portion18, namely, they are offset toward the base edge119bof the recessed edge119aso that they do not pass through the center5aof the opening5.

The shutter piece103has a front-end surface180below the front-end edge14cwhich is offset closer to the base-end14bthan the front-end edge14c. The front-end surface180is a combination of an upper front-end surface182and a lower front-end surface184(seeFIG.26). The upper front-end surface182is a substantially quadrangular surface with opposite sides, namely, the front edge162cof the vertical portion162of the opening-side surface107and the front edge172cof the vertical portion172of the abutting-side surface109. Further, the lower front-end surface184is a substantially quadrangular surface with opposite sides, namely, the front edge164cof the lower slope portion164of the opening-side surface107and the front edge174cof the lower slope portion174of the abutting-side surface109. The front-end surface180is formed so as to intersect the lower portions115,119on the front-end side of the lower portions115,119. Further, the shutter piece103has a downward horizontal surface extending from an upper end of the front-end surface180toward the front-end side of the shutter piece103. When the shutter piece103is viewed from its bottom, a planar intermediate lower surface103f, which includes this horizontal surface and a horizontal portion170of the lower portion119, is formed on the front side of the shutter piece103(seeFIG.26).

Locating the front end13eof the upper edge13aof the opening-side surface107of the shutter piece103at the center5aof the opening5causes a state in which the opening5of the shutter set102is closed by the front end13e(the starting closing state) (seeFIG.34). At this time, the front-end edges13c,14c, the front edges172c,174c, and the front-side portion of the lower intermediate edge14dof the shutter piece103abut the upper portion13, the intermediate portion14, and the lower portion115of the opening-side surface107of the adjacent shutter piece103, respectively. Thus, on the opening-side surface107of each shutter piece103, a ceiling space SS1with concaveness and convexness is formed and surrounded by the inclined upper portion13, the vertically-extending intermediate portion14, the lower portion115protruding toward the opening5, the front-end surface180offset from the front end toward the base end of the shutter piece103, and the lower portion119and the intermediate lower surface103fcontinuous to the front-end surface180. The ceiling space SS1is defined in a top-down order by a first space SS11with a substantially octagonal pyramid surrounded by the eight upper portions13, a second space SS12with a substantially octagonal prism surrounded by the eight intermediate portions14, and the remaining third space SS13.

While the shutter set102is moved from the starting closing state to the fully-closed state (seeFIG.36), the ceiling space SS1is entirely reduced. Specifically, a height and a diameter of the first space SS11are reduced, and a diameter of the second space SS12is reduced.

As a result, when the shutter set102reaches the fully-closed state, the first space SS11and the second space SS12have not existed, so that the ceiling space SS1is defined only by the reduced third space SS13. Specifically, a ceiling of the third space SS13is defined by the intermediate lower surfaces103fon the front side of the eight shutter pieces103, while the remaining of the third space SS13is surrounded by the eight front-end surfaces180offset from the front-end edges13c,14ctoward the base-end side, and the lower portion119continuous to the front-end surface180.

Next, referring toFIGS.27-37, an operation of the forming apparatus101will be explained. Detailed explanation of portions of the operation of the forming apparatus101according to the second embodiment which are similar to portions of the operation of the forming apparatus1according to the first embodiment is omitted.

As shown inFIG.27, the disk-like outer skin material D on which the inner material F is deposited is conveyed by the supply conveyor device21to a position at the center5aof the opening5.

As shown inFIG.28, the front-end portion21aof the supply conveyor device21is retracted from the extended position to the standby position, so that the outer skin material D and the inner material F are placed onto the hole plate23b.

As shown inFIG.29, the shutter device23is actuated to move the shutter set102toward the closed state. The vertical portion162of the lower portion115of the shutter piece103is allowed to contact the peripheral edge portion DE of the outer skin material D, and then, the horizontal portion160is allowed to get under the lower surface of the peripheral edge DE. Further, after the intermediate portion14is allowed to contact the peripheral edge of the outer skin material D, the closing action of the shutter set102is temporarily stopped.

As shown inFIG.30, the press member25aof the press device25is lowered, and the peripheral edge portion DE of the outer skin material D is pressed against the hole plate23bto seal the inner space formed between the outer skin material D and the press member25a.

As shown inFIG.31, by supplying compressed air into the inner space, the outer skin material D is expanded downward inside of the opening23cto form a bowl-like shape. A bottom portion of the downward expanded outer skin material D is supported by the support device27.

As shown inFIG.32, the press member25ais raised. As shown inFIG.33, the shutter set102is moved toward the closed state again. The protruding lower portion115of the shutter piece103allows the outer skin material D near the inner material F to be held and, at the same time, concentrically gathered and stretched toward a position above the center of the inner material F. Since the horizontal portion160is configured to protrude more than the horizontal portion60in the first embodiment, an effect of holding the outer skin material D can be further enhanced. Further, since the lower slope portion164of the lower portion115is configured to be a convex curved surface having a larger curvature than a curvature of the lower slope portion64of the first embodiment, the effect of preventing the roughening of the surface can be further enhanced.

The closing action of the shutter set102is forwarded, and the inner material F is enveloped to be sealed by the outer skin material D surrounded by the eight lower portions115at a position above the inner material F. As shown inFIG.34, the closing action of the shutter set102is further forwarded so that the opening5of the shutter set102is closed to form the ceiling space SS1.

As shown inFIG.35, as the closing action of the shutter set102is forwarded, a volume of the ceiling space SS1is reduced. In the present embodiment, the lower portion115does not include an upper slope portion, and an upward surface is formed only by the horizontal portion160. Thus, an effect of holding the outer skin material D by the lower portion115is larger than that in the first embodiment, while the outer skin material D remaining inside of the ceiling space SS1is subject to a strong pressure from the shutter set102and pushed out. As a result, the peripheral edge portion DE of the outer skin material D is firmly attached and sealed to itself.

Further, as the ceiling space SS1is gradually reduced, a protruding width of the lower portion115becomes smaller, so that the third space SS13is not closed and the opening can be maintained.

As shown inFIG.36, the shutter set2is moved to the fully-closed state, so that the closing action of the shutter set (unit)2is stopped, and the sealing operation of the outer skin material D due to the shutter set (unit)2is finished. At this time, the ceiling space SS1exists only at the reduced third space SS13.

As shown inFIG.37, the shutter set102is moved toward the opened state, the outer skin material D of the head of the enveloped food product P is released, and the support device27on which the enveloped food product P is deposited is lowered.

Next, referring toFIGS.40-43, a shutter piece and a shutter set according to a third embodiment of the present invention will be explained.

A shutter piece403of the third embodiment according to the present invention has a structure which is similar to that of the shutter piece3of the first embodiment, but is different mainly from the upper portions13,17, the lower portions15,19and the front-end surface80of the shutter piece3. Components of the shutter piece403according to the third embodiment, which are similar to those of the shutter piece3according to the first embodiment, have the same reference numerals as those of the shutter piece3, and their detailed explanation is omitted.

As shown inFIGS.40-43, the shutter piece403has the upper surface3a, the lower surface3b, and side surfaces407,409,11located between the upper surface3aand the lower surface3b. The side surfaces407,409,11includes an opening-side surface407defining the opening5, an abutting-side surface409defining the front-end edges13c,14ctogether with the opening-side surface407, and the other side surfaces11.

The opening-side surface407of the shutter piece403includes the upper portion13, the intermediate portion14, and a lower portion415.

The upper portion13includes an upper slope portion413aand a lower slope portion413b. The upper slope portion413aof the upper portion13is mainly defined by the upper edge13a, a slope edge413d, and a front-end edge413ca, and extends obliquely downward from the upper edge13atoward the slope edge413dso as to be recessed from the upper edge13a. The lower slope portion413bis mainly defined by the slope edge413d, the intermediate edge14a, and a front-end edge413cb, and extends obliquely downward from the slope edge413dtoward the intermediate edge14aso as to be recessed from the slope edge413d. The upper slope portion413ahas a downward slope which is preferably steeper than that of the lower slope portion413b. The position of the front-end edge13c(413ca,413cb) of the upper portion13is preferably determined to pass through the center5aof the opening5of a shutter set402when the shutter piece403is swung.

In the plan view, a front-side portion of the lower portion415is disposed to be recessed from the upper edge13a, but to be protruded from the intermediate edge14aand the lower intermediate edge14d(the intermediate portion14), and has a protruding edge415awhich is convex and arcuate. The protruding edge415aextends from a base end415bto a front end415e(seeFIG.41). In the plan view, the protruding edge415ais located between the upper edge13aand the intermediate edge14a(lower intermediate edge14d). In the plan view, the front end415eand the base end415bare recessed toward the abutting-side surface409from the upper edge13aand protruded toward the opening5(toward the opening-side surface407) from the intermediate edge14a(lower intermediate edge14d).

Specifically, the front-side portion of the lower portion415includes three surfaces, namely, an upper slope portion460, a vertical portion462, and a lower slope portion464. The upper slope portion460is an upward surface disposed along the lower intermediate edge14d(intermediate portion14) and extends obliquely downward to protrude from the lower intermediate edge14d(intermediate portion14). In the plan view, a width of the upper slope portion460protruding from the intermediate portion14becomes larger from the base end415btoward the front end415e(seeFIGS.42and43). The vertical portion462extends downward from the upper slope portion460. The lower slope portion464extends obliquely downward to the lower edge15d(lower surface3b) to be recessed from the vertical portion462. The convex protruding edge415ais a peripheral edge of the lower portion415and is defined by a boundary line between the upper slope portion460and the vertical portion462. In the plan view, a width between the protruding edge415aand the intermediate edge14abecomes larger from the base end415btoward the front end415e(seeFIGS.40,42and43).

The upper slope portion460extends obliquely downward to the protruding edge415ato protrude from the lower intermediate edge14d(intermediate portion14). The vertical portion462is preferably a curved surface extending downward from the protruding edge415ato the lower protruding edge415dand vertically has the same contour. The lower protruding edge415dextends from a base end415fto a front end415g. Further, the lower slope portion464is preferably an inclined surface extending obliquely downward from the lower protruding edge415dof the vertical portion462, and a profile of a vertical section of this inclined surface may be a straight line, a convex curved line, or a combination thereof. In this embodiment, the profile of the vertical section of the inclined surface of the lower slope portion464is a convex curved line. In the plan view, the lower edge15dwhere the lower slope portion464intersects the lower surface3bextends in a convex and arcuate way (seeFIG.42).

As shown inFIG.41, the lower portion415further has a front edge460con a front side of the upper slope portion460, a front edge462con a front side of the vertical portion462, and a front edge464con a front side of the lower slope portion464. The front end415eof the protruding edge415ais an intersection of the front edge460cof the upper slope portion460and the front edge462cof the vertical portion462. The front end415gof the lower protruding edge415dis an intersection of the front edge462cof the vertical portion462and the front edge464cof the lower slope portion464.

Further, in the plan view, the front edge460cof the upper slope portion460, the front edge462cof the vertical portion462, and the front edge464cof the lower slope portion464are not located at the front-end edge13cof the upper portion13and the front-end edge14cof the intermediate portion14, namely, they are offset toward the base end415bof the protruding edge415aso that they do not pass through the center5aof the opening5. In the present embodiment, as shown inFIG.41, the upper slope portion460, the vertical portion462, and the lower slope portion464are formed with degrees relative to the front-end edge14cof the intermediate portion14(a direction of the front end14eof the intermediate edge14ain the front view), for example, with forty-five degrees.

As shown inFIGS.40-43, the abutting-side surface409of the shutter piece403has the upper portion17, the intermediate portion18, and a lower portion419. Further, the upper portion17includes an upper slope portion417aand a lower slope portion417b, and the lower portion419includes an upper slope portion470, a vertical portion472, and a lower slope portion474.

As shown inFIGS.40-43, the upper slope portion417aof the upper portion17is mainly defined by the upper edge17a, a slope edge417dand a front-end edge413ca, and extends obliquely downward from the upper edge17atoward the slope edge417dto protrude from the upper edge17a. The lower slope portion417bis mainly defined by the slope edge417d, the intermediate edge18a, and a front-end edge413cb, and extends obliquely downward from the slope edge417dtoward the intermediate edge18ato protrude from the slope edge417d. The upper slope portion417ahas a downward slope which is preferably steeper than that of the lower slope portion417b.

The upper slope portion470of the lower portion415extends obliquely downward to be recessed from the lower intermediate edge18dand has a front edge470con its front side. The vertical portion472extends downward from the upper slope portion470and has a front edge472con its front side. The lower slope portion474extends to the lower edge19d(lower surface3b) to protrude obliquely downward from the vertical portion472and has a front edge474con its front side. A recessed edge419abetween the upper slope portion470and the vertical portion472extends from a base end to the front end419e, and the front end419eis an intersection of the front edge470cof the upper slope portion470and the front edge472cof the vertical portion472. A lower recessed edge419dbetween the vertical portion472and the lower slope portion474extends from a base end to a front end419g, and the front end419gis an intersection of the front edge472cof the vertical portion472and the front edge474cof the lower slope portion474.

Preferably, the front-end edge13c(413ca,413cb), the front-end edge14c, and the front edges470c,472c,474care formed to always abut the upper portion13, the intermediate portion14, and the upper slope portion460, the vertical portion462, and the lower slope portion464of the lower portion415of the opening-side surface407of the adjacent shutter piece403, respectively, without substantially causing any clearance when the shutter piece403is swung.

The upper portion17, the intermediate portion18, and the lower portion419of the abutting-side surface109are preferably formed in a concave shape to abut the upper portion13, the intermediate portion14, and the lower portion415in the opening-side surface407of the adjacent shutter piece, respectively, when the shutter set404is in the fully-closed state.

Specifically, the upper edge13a, the slope edge413d, and the intermediate edge14aof the upper portion13of the opening-side surface407can abut the upper edge17a, the slope edge417d, and the intermediate edge18aof the upper portion17of the abutting-side surface409of the adjacent shutter piece403, respectively. The intermediate edge14aand the lower intermediate edge14dof the intermediate portion14of the opening-side surface407can abut the intermediate edge18aand the lower intermediate edge18dof the intermediate portion18of the abutting-side surface409of the adjacent shutter piece403, respectively. The protruding edge415a, the lower protruding edge415d, and the lower edge15dof the lower portion415of the opening-side surface407can abut the recessed edge419a, the lower recessed edge419d, and the lower edge19dof the lower portion419of the abutting-side surface409of the adjacent shutter piece403, respectively. Namely, in the plan view, each of the upper edge17a, the slope edge417d, the intermediate edge18a, the lower intermediate edge18d, the recessed edge419a, the lower recessed edge419d, and the lower edge19dof the abutting-side surface409is formed to be concave and arcuate.

Further, in the plan view, the front edge470cof the upper slope portion470, the front edge472cof the vertical portion472, and the front edge474cof the lower slope portion474are not located at the front-end edge13cof the upper portion17and the front-end edge14cof the intermediate portion18, namely, they are offset toward the base end419bof the recessed edge419aso that they do not pass through the center5aof the opening5.

The shutter piece403has a front-end surface480below the front-end edge14cwhich is offset closer to the base end14bthan the front-end edge14c. The front-end surface480is formed to intersect the lower portions415,419on the front-end side of the lower portions415,419.

Locating the front end13eof the upper edge13aof the opening side surface407of the shutter piece403at the center Sa of the opening5causes a state in which the opening5of the shutter set402is closed by the front end13e(starting closing state). At this time, the front-end edges13c(413ca,413cb),14c, and the front edges470c,472c,474cabut the upper portion13, the intermediate portion14and the lower portion415of the opening-side surface407of the adjacent shutter pieces403, respectively. Thus, on the opening-side surface407of each shutter piece403, a ceiling space SS4with concaveness and convexness is formed and surrounded by the inclined upper portion13, the vertically-extending intermediate portion14, the lower portion415protruding toward the opening5, and the front-end surface480offset from the front end toward the base end of the shutter piece403. The ceiling space SS4is defined in a top-down order by a first space SS41with substantially octagonal pyramid and frustum surrounded by the eight upper portions13, a second space SS42with a substantially octagonal prism surrounded by the eight intermediate portions14, and the remaining third space SS43.

While the shutter set402is moved from the starting closing state to the fully-closed state, the ceiling space SS4is entirely reduced. Specifically, a height and a diameter of the first space SS41are reduced, and a diameter of the second space SS42is reduced.

As a result, when the shutter set402reaches the fully-closed state, the first space SS41and the second space SS42have not existed so that the ceiling space SS4is defined only by the third space SS43.

Next, referring toFIGS.44-48, an operation of the forming apparatus401will be explained. Detailed explanation of portions of the operation of the forming apparatus104according to the third embodiment which are similar to portions of the operation of the forming apparatus1according to the first embodiment is omitted. Specifically, sinceFIGS.12-17according to the first embodiment is substantially common to the third embodiment, explanation ofFIGS.12-17is omitted.

As shown inFIG.44, the shutter set402is moved toward the fully-closed state. The protruding lower portion415of the shutter piece403allows the outer skin material D near the inner material F to be held and, at the same time, concentrically gathered and stretched toward a position above the center of the inner material F. In the plan view, since a width of the upper slope portion460protruding from the intermediate portion14becomes larger from the base end415btoward the front end415e, as the shutter set402is moved closer to the fully-closed state, a force for holding the outer skin material D can be become larger. Further, the outer skin material D can be held until a timing immediately before the shutter set402is moved to the fully-closed state. As a result, an amount of gathering the outer skin material D can be stabilized, and the production can be stabilized. Further, since the lower slope portion464of the lower portion415is formed of a convex curved surface, the effect of preventing the roughening on the surface can be further enhanced.

The closing action of the shutter set402is forwarded, and the inner material F is enveloped to be sealed by the outer skin material D surrounded by the eight lower portions15at a position above the inner material F. As shown inFIG.45, the closing action of the shutter set102is further forwarded so that the opening5of the shutter set102is closed to form the ceiling space SS4.

As shown inFIG.46, as the closing action of the shutter set102is forwarded, a volume of the ceiling space SS4is reduced. As a result, the peripheral edge portion DE of the outer skin material D is firmly sealed.

Further, since the front sides of the upper slope portion460, the vertical portion462, and the lower slope portion464are formed by forty-five degrees relative to the front-end edge14cof the intermediate portion14, as the ceiling space SS4is gradually reduced, the opening can be maintained without closing the third space SS43.

As shown inFIG.47, the shutter set402is moved to the fully-closed state, so that the closing action of the shutter set (unit)402is stopped, and the sealing operation of the outer skin material D due to the shutter set (unit)402is finished. At this time, the ceiling space SS4exists only at the reduced third space SS43.

As shown inFIG.48, the shutter set402is moved toward the opened state, the outer skin material D of the head of the enveloped food product P is released, and the support device27on which the enveloped food product P is deposited is lowered.

Explanation of the shutter piece and the shutter set according to the embodiments of the present invention has been generally done, but the present invention is not limited to the above-explained shutter piece and the shutter set so that various modifications can be done within the scope of the claims.

For example, while in the above-stated embodiments, the shutter piece3,103,403has been explained to include the intermediate portion14,18, the intermediate portion may be omitted, as a shutter piece203of a first alternative of the first embodiment shown inFIG.38.

The shutter piece203includes an opening-side surface207and an abutting-side surface209. The opening-side surface207includes the upper portion13and the lower portion15below the upper portion13. A profile of a vertical section of the upper portion13is recessed. In the plan view, the protruding edge15aof the lower portion15is located between the upper edge13aand the intermediate and lower edges14a,13d. Further, the abutting-side surface209includes the upper and lower portions17,19corresponding to the opening-side surface207.

Even in this alternative, a ceiling space can be formed in the shutter unit, so that the outer skin material D to be attached and sealed to itself is not leaked onto an upper surface of the shutter unit to form an enveloped food product P. Further, since the profile of the vertical section of the upper portion13is formed to be recessed, an amount of storing the outer skin material in the ceiling space can increase and a third space can be formed for assuming a role of a squeezing valve in the ceiling space, so that the peripheral edge portion DE of the outer skin material D can be surely attached and sealed to itself.

Further, as a shutter piece303of a second alternative of the first embodiment shown inFIG.39, a vertical portion may be added between the upper slope portion and the lower slope portion of the lower portion.

A lower portion315of an opening-side surface307of a shutter piece303includes a horizontal portion60, an upper slope portion62, a vertical portion63, and a lower slope portion64. The vertical portion63extends downward from the protruding edge15a, namely, a lower end of the upper slope portion62and is a curved surface vertically having the same contour. Further, the lower slope portion64extends obliquely downward from the vertical portion63to be recessed from the vertical portion63.

An abutting-side surface309of the shutter piece303includes a lower portion319corresponding to the lower portion315of the opening side surface307. Further, a front-end surface380intersects the lower portions315,319on a front side of the lower portions315,319. In this way, by causing the height of the lower portion to be larger to lengthen a passage of the third space S3, the outer skin material D can be subject to a high pressure to be pushed out from the ceiling space S, so that the peripheral portion DE of the outer skin material D can be surely attached and sealed to itself.

Further, a vertical portion which has the same contour as that of the upper surface3aof the shutter piece3may be added to extend from the upper portion13,15. Even in this case, the ceiling space S can be formed.1,101,401: forming apparatus2,102,402: shutter set3,103,403: shutter piece3c: front edge3f: intermediate lower surface (horizontal lower surface)4c: front edge5: opening5a: center7,107,207,307,407: opening-side surface9,109,209,309,409: abutting-side surface13: upper portion (first side surface)13a: upper edge (peripheral edge)13b: base end13e: front end13d: lower edge14: intermediate portion (intermediate side surface)14a: intermediate edge (lower edge of the upper portion)15,115,315,415: lower portion (second side surface)15a,115a,415a: protruding edge (peripheral edge)15b,115b,415b: base end15e,115e,415e: front end23: shutter device60,160: horizontal portion62: upper slope portion63: vertical portion64,164: lower slope portion80,180,380: front surface162: vertical portionD: outer skin material (food dough)DE: peripheral portionF: inner materialP: enveloped food productS, SS1, SS4: ceiling spaceS1, SS11, SS41: first spaceS2, SS14, SS42: second spaceS3, SS13, SS43: third space