CN219803804U - Delivery bag - Google Patents

Abstract

The utility model belongs to the technical field of delivery bags, and particularly relates to a delivery bag, which comprises a delivery box and further comprises: the two clapboards are arranged in total, the two clapboards are fixedly arranged in the delivery box, and a placing mechanism is arranged between the two clapboards; the placement machine constructs, placement machine constructs including the brace table, brace table fixed mounting is in the inside bottom of delivery box, the shrink chamber has all been seted up to the both sides in brace table top, the inside in both sides shrink chamber is equal fixedly connected with spring, both sides the equal fixedly connected with stopper of the other end of spring, the top activity of brace table has cup jointed the storing frame, the storing frame has all run through on the surface that is close to the bottom both sides and has offered the joint groove, for prior art, but the regular categorised depositing of delivery product has been reached to this utility model, the effect of follow-up taking of being convenient for.

Description

Delivery bag

Technical Field

The utility model belongs to the technical field of delivery bags, and particularly relates to a delivery bag.

Background

The delivery room is a room for women to deliver, the delivery bag is one of medical appliances needed by the delivery room, the delivery product is made of non-woven fabrics, and the delivery product is sterilized by ethylene oxide, and the components comprise surgical gowns, masks, examination gloves, hats, therapeutic towels, blood pads, medical gauze pieces, medical cotton swabs, middle sheets, infant care sheets, umbilical cord clamps, umbilical cords, bellyband, infant diapers, shoe covers, leg covers, wrapping cloths and the like.

The utility model discloses a delivery bag for delivery nursing, including the storage mechanism that can place the nursing apparatus that delivery used, storage mechanism bottom set firmly separating mechanism, separating mechanism bottom can install firm coupling mechanism with delivery bed or delivery chair, coupling mechanism inside slide and be equipped with the stop gear that can lock separating mechanism and coupling mechanism after installation, coupling mechanism front end in slide and be equipped with the release mechanism that can release stop gear locking function, this delivery bag for delivery nursing can be with the delivery bed or delivery chair connection firm, avoids the inclusion to be collided by external force, and then leads to the event emergence of nursing articles unrestrained ground, in addition, the device's inclusion can dismantle alone, the inclusion of being convenient for medical personnel to change the inclusion of new, ensured that the inclusion uses and makes the cleanliness, can, through the device in the utility model, ensured medical personnel's work progress. However, when the device is used, different instruments are difficult to store regularly, the subsequent convenient use is inconvenient, the instruments are easy to rub and damage, the volume of the delivery bag is increased, and a large storage space is occupied, so that improvement is necessary.

Disclosure of Invention

The utility model aims at solving the technical problems, and provides a delivery bag, which achieves the effects of regularly classifying and storing delivery products and facilitating subsequent taking.

In view of the above, the present utility model provides a delivery package, including a delivery box, further including:

the two clapboards are arranged in total, the two clapboards are fixedly arranged in the delivery box, and a placing mechanism is arranged between the two clapboards;

the placement mechanism comprises a supporting table, the supporting table is fixedly arranged at the bottom of the inside of the delivery box, contraction cavities are formed in two sides of the top end of the supporting table, springs are fixedly connected to the inside of the contraction cavities on two sides, limiting blocks are fixedly connected to the other ends of the springs on two sides, a storage frame is movably sleeved at the top end of the supporting table, clamping grooves are formed in the surfaces, close to the two sides of the bottom end, of the storage frame in a penetrating mode, and a plurality of storage grooves are uniformly formed in the surfaces of the other two sides of the storage frame in an equidistant mode;

the limiting blocks at two sides are respectively connected with the clamping grooves at two sides in a clamping mode.

In this technical scheme, divide into the triplex through the internal separation of two baffles with the delivery box, therefore can carry out regular classification to different article and deposit, take when being convenient for follow-up use, the practicality of device has been improved, be provided with placement mechanism between two baffles in addition, therefore can place the further classification of apparatus in different storage intracavity portion, and the storing frame can promote, so can rise it when using, be convenient for medical personnel more to take of article, and can descend it when not using, pack up it, avoid occupation in more spaces.

In the above technical solution, further, the method further includes:

the fixing mechanism comprises four supports and a barrel sleeve, the four supports are respectively and fixedly installed on the periphery of the lower surface of the receiving box, the bottoms of the four supports are respectively provided with a receiving cavity, the inside of each receiving cavity is respectively and slidably clamped with a sucker, the four barrel sleeves are respectively and fixedly installed on the periphery of the bottom of the receiving box, the upper surfaces of the four barrel sleeves are respectively and fixedly connected with threaded rods in a penetrating and connecting mode, the tops of the threaded rods are respectively and fixedly connected with a rotator, and the bottoms of the threaded rods are respectively and fixedly connected with a connecting rod;

the bottom of the connecting rod penetrates through the bottom of the inside of the birth control box and extends to the inside of the storage cavity, and the bottom of the connecting rod is fixedly connected with the surface of one side of the sucker.

In this technical scheme, drive the threaded rod through rotating the ware and rotate for the threaded rod reciprocates at the barrel casing, and the barrel casing removes and will drive the connecting rod and reciprocate, thereby adjusts the length of sucking disc extension support, makes when using the device, can utilize the sucking disc to carry out the actuation fixedly, reduces its and produces the possibility that removes to drop, and also can pack up it when it does not use, conveniently mentions to the birth control case, has increased the stability and the usability of device.

In the above technical solution, further, the method further includes:

the delivery box is provided with a sealing cover at the upper end;

the sealing cover comprises a cover plate and a mounting frame, wherein a rotating plate is fixedly connected to the surface of one side of the cover plate, two rotating plates and two mounting frames are respectively arranged on the surface of the outer part of the delivery box, two rotating plates and two mounting frames are connected through a rotating shaft, and a rubber pad is fixedly connected to the surface of one side of the cover plate, close to the delivery box.

In this technical scheme, through being provided with sealed lid, consequently can seal the upper end of receiving the birth control case, avoid dust impurity to fall into wherein and cause the pollution to it, increased the sanitation of device, and sealed lid comprises apron and rubber pad, and rubber is soft can be appropriate produce deformation, makes its and the sealed inseparabler of receiving the birth control case mouth, has improved sealed effect.

In the above technical solution, further, the method further includes:

the delivery box is characterized in that locking discs are fixedly connected to the periphery of the upper surface of the delivery box, and locking holes are formed in the upper surface of each locking disc in a penetrating manner;

the periphery of the upper surface of the sealing cover is provided with a locking mechanism;

the locking mechanism comprises a locking rod which is rotationally inserted on the surface of the cover plate, the top end of the locking rod is fixedly connected with a screwing device, and the bottom end of the locking rod is fixedly connected with a locking block;

the locking block is matched with the locking hole in shape and size, and is connected with the plug-in connector.

In this technical scheme, through together inserting the inside in locking hole with locking lever intercommunication locking hole, rethread twister drives the individual latch segment of locking lever and rotates for latch segment and locking dish block, thereby fix sealed lid, tightly fixed sealed lid and the delivery box through the mode of block and cartridge, open when being convenient for later stage use more.

In the above technical solution, further, the method further includes:

the surface of one side of the outer part of the delivery box is provided with a bearing mechanism, and the bearing mechanism is positioned on the same side of the mounting frame;

the knapsack mechanism comprises a backboard, the backboard is fixedly arranged on the surface of the delivery box, the surface of one side of the backboard, which is far away from the delivery box, is fixedly connected with braces, and the number of the braces is two.

In this technical scheme, through the setting of braces and backplate, can make things convenient for the birth control case to remove more, and the mode of bearing can liberate user's both hands, makes it can carry out other operations, has improved the usability of device.

In the above technical solution, further, the method further includes:

the upper surface of the sealing cover is fixedly provided with a lifting ring.

In the technical scheme, the whole mobile device can be easily moved by the lifting ring.

In the above technical solution, further, the method further includes:

the surface of the backboard, which is far away from one side of the birth receiving box, is provided with a curved surface which is concave inwards.

In this technical scheme, the backplate is close to one side of human body and sets up to the curved surface to the body of human body is laminated more, makes more comfortable when carrying.

The beneficial effects of the utility model are as follows:

1. the inside of the delivery box is divided into three parts by the two partition boards, so that different articles can be regularly classified and stored, the articles can be conveniently taken out during subsequent use, the practicability of the device is improved, in addition, the placement mechanism is arranged between the two partition boards, so that the instruments can be further classified and placed in different storage cavities, and the storage frame can be lifted, so that the articles can be lifted during use, the articles can be more conveniently taken out by medical staff, and the articles can be lowered and collected during non-use, and the occupation of more space is avoided;

2. the threaded rod is driven to rotate by the rotating device, so that the threaded rod moves up and down on the sleeve, the sleeve moves to drive the connecting rod to move up and down, the length of the sucker extension support is adjusted, the sucker can be used for sucking and fixing when the device is used, the possibility of moving and falling is reduced, the device can be folded when the device is not used, the lifting of the junction box is facilitated, and the stability and usability of the device are improved;

3. the sealing cover is arranged, so that the upper end of the delivery box can be sealed, dust and impurities are prevented from falling into the sealing cover to pollute the delivery box, the sanitation of the device is improved, the sealing cover consists of the cover plate and the rubber pad, the rubber texture is softer and can be deformed properly, the sealing between the sealing cover and the delivery box is tighter, and the sealing effect is improved;

4. through together inserting the inside in locking hole with locking lever intercommunication locking hole, rethread twister drives the individual latch segment of locking lever and rotates for latch segment and locking dish block, thereby fix sealed lid, tightly fix sealed lid and the joint case through block and the mode of inserting, open when being convenient for later stage use more.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the utility model, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

Fig. 1 is a schematic view of the overall first perspective structure of the present utility model.

Fig. 2 is a schematic view of the overall second perspective structure of the present utility model.

Fig. 3 is a schematic view of the overall third perspective structure of the present utility model.

Fig. 4 is a schematic view of a first perspective structure of the present utility model in an opened state.

Fig. 5 is a second perspective view illustrating an opened state of the present utility model.

FIG. 6 is a schematic view of the whole cross-sectional structure of the present utility model.

The label in the figure is:

the novel baby carrier comprises a delivery box 1, a sealing cover 2, a cover plate 201, a rubber pad 202, a rotating plate 203, a mounting frame 204, a locking mechanism 3, a locking rod 301, a screwing device 302, a locking block 303, a fixing mechanism 4, a support 401, a containing cavity 402, a sucker 403, a barrel 404, a connecting rod 405, a threaded rod 406, a rotator 407, a lifting ring 5, a carrying mechanism 6, a back plate 601, a carrying strap 602, a placing mechanism 7, a storage frame 701, a supporting table 702, a storage groove 703, a clamping groove 704, a limiting block 705, a spring 706, a partition plate 8, a locking disc 9 and a locking hole 10.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments in accordance with the present utility model. For ease of description, the dimensions of the various features shown in the drawings are not drawn to actual scale. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

It should be noted that the terms "first," "second," and the like in the description and in the claims are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present utility model may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

It should be noted that, in the description of the present utility model, the terms like "front, rear, upper, lower, left, right", "horizontal, vertical, horizontal", and "top, bottom", etc. generally refer to the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the present utility model and simplifying the description, and these orientation terms do not indicate and imply that the apparatus or elements referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the scope of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

It should be noted that, in the present utility model, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present utility model is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

Example 1:

the embodiment of the utility model provides a delivery package, which comprises a delivery box 1 and further comprises: the two clapboards 8 are arranged in total, the two clapboards 8 are fixedly arranged in the delivery box 1, and a placing mechanism 7 is arranged between the two clapboards 8; the placement mechanism 7 comprises a supporting table 702, wherein the supporting table 702 is fixedly arranged at the bottom of the inside of the delivery box 1, contraction cavities are formed in two sides of the top end of the supporting table 702, springs 706 are fixedly connected to the inside of the contraction cavities on two sides, limiting blocks 705 are fixedly connected to the other ends of the springs 706 on two sides, a storage frame 701 is movably sleeved at the top end of the supporting table 702, clamping grooves 704 are formed in the surfaces, close to the two sides of the bottom end, of the storage frame 701 in a penetrating mode, and a plurality of storage grooves 703 are uniformly formed in the surfaces of the other two sides of the storage frame 701 in an equidistant mode;

the two side limiting blocks 705 are respectively connected with the two side clamping grooves 704 in a clamping manner.

In this embodiment, divide into the triplex through the internal separation of two baffles with the delivery box, therefore can carry out regular classification to different article and deposit, take when being convenient for follow-up use, the practicality of device has been improved, be provided with placement mechanism between two baffles in addition, therefore can place the further classification of apparatus in different storage intracavity portion, and the storing frame can promote, so can rise it when using, be convenient for medical personnel more to take of article, and can descend it when not using, pack up it, avoid occupation in more spaces.

Example 2:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the fixing mechanism 4 comprises four supports 401 and sleeves 404, the four supports 401 and the sleeves 404 are respectively arranged, the four supports 401 are respectively and fixedly installed on the periphery of the lower surface of the reception box 1, the bottoms of the four supports 401 are respectively provided with a storage cavity 402, the inside of each storage cavity 402 is respectively and slidably clamped with a sucker 403, the four sleeves 404 are respectively and fixedly installed on the periphery of the bottom inside the reception box 1, the upper surfaces of the four sleeves 404 are respectively and fixedly connected with threaded rods 406 in a penetrating threaded insertion manner, the top ends of the four threaded rods 406 are respectively and fixedly connected with a rotator 407, and the bottom ends of the four threaded rods 406 are respectively and fixedly connected with a connecting rod 405;

the bottom end of the connecting rod 405 penetrates through the bottom of the inside of the incubator 1 and extends to the inside of the accommodating cavity 402, and the bottom end of the connecting rod 405 is fixedly connected with the surface of one side of the sucker 403.

In this embodiment, drive the threaded rod through rotating the ware and rotate for the threaded rod reciprocates at the barrel casing, and the barrel casing removes and will drive the connecting rod and reciprocate, thereby adjusts the length of sucking disc extension support, makes when using the device, can utilize the sucking disc to carry out actuation fixedly, reduces its and produces the possibility that removes and drop, and also can pack up it when it does not use, conveniently mentions the device's stability and usability to the birth control case.

Example 3:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the delivery box 1, the upper end of the delivery box 1 is provided with a sealing cover 2; the sealing cover 2, the sealing cover 2 includes apron 201 and mounting bracket 204, and the fixed surface of apron 201 one side is connected with the commentaries on classics board 203, and commentaries on classics board 203 and mounting bracket 204 are provided with two respectively, and two equal fixed mounting of mounting bracket 204 are on the surface of the external portion of the delivery box 1, and two commentaries on classics board 203 and two mounting brackets 204 are all connected through the pivot, and the apron 201 is close to the fixed surface of delivery box 1 one side and is connected with rubber pad 202.

In this embodiment, through being provided with sealed lid, consequently can seal the upper end of delivery box, avoid dust impurity to fall into wherein and cause the pollution to it, increased the sanitation of device, and sealed lid comprises apron and rubber pad, and rubber body is comparatively soft can be appropriate production deformation, makes its and the sealing of delivery box mouth inseparabler, has improved sealed effect.

Example 4:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the delivery box 1, the circumference of the upper surface of the delivery box 1 is fixedly connected with locking discs 9, and the upper surface of each locking disc 9 is provided with a locking hole 10 in a penetrating way; the periphery of the upper surface of the sealing cover 2 is provided with a locking mechanism 3; the locking mechanism 3, the locking mechanism 3 comprises a locking rod 301, the locking rod 301 is rotationally inserted on the surface of the cover plate 201, the top end of the locking rod 301 is fixedly connected with a twister 302, and the bottom end of the locking rod 301 is fixedly connected with a locking block 303;

the locking block 303 is matched with the shape and the size of the locking hole 10, and the locking blocks 303 and 304 are connected in an inserting way.

In this embodiment, through together inserting the inside in locking hole with locking lever intercommunication locking hole, rethread twister drives the individual latch segment of locking lever and rotates for latch segment and locking dish block, thereby fix sealed lid, tightly fix sealed lid and the reception case through the mode of block and cartridge, open when being convenient for later stage use more.

Example 5:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the surface of one side of the outer part of the delivery box 1 is provided with a carrying mechanism 6, and the carrying mechanism 6 is positioned on the same side of the mounting frame 204; the back carrying mechanism 6 comprises a back board 601, the back board 601 is fixedly arranged on the surface of the delivery box 1, the surface of one side of the back board 601 away from the delivery box 1 is fixedly connected with a back strap 602, and the back strap 602 is provided with two back straps.

In this embodiment, through the setting of braces and backplate, can make things convenient for more to the birth control case remove, and the mode of bearing can liberate user's both hands, makes it can carry out other operations, has improved the usability of device.

Example 6:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the upper surface of the sealing cover 2 is fixedly provided with a lifting ring 5.

In this embodiment, the whole mobile device can be easily moved by the lifting ring, so that the adoption of the encircling type taking mode is avoided.

Example 7:

the present embodiment provides a delivery package, which includes the following technical features in addition to the technical scheme of the foregoing embodiment, and further includes: the surface of the back plate 601 on the side away from the delivery box 1 is provided as a curved surface recessed inward.

In this embodiment, the backplate is close to the one side of human body and sets up to the curved surface to the body of human body is laminated more, makes to bear more comfortablely when carrying.

The embodiments of the present utility model have been described above with reference to the accompanying drawings, in which the embodiments of the present utility model and features of the embodiments may be combined with each other without conflict, the present utility model is not limited to the above-described embodiments, which are merely illustrative, not restrictive, of the present utility model, and many forms may be made by those of ordinary skill in the art without departing from the spirit of the present utility model and the scope of the claims, which are protected by the present utility model.

Claims (7)

1. The delivery bag comprises a delivery box (1), and is characterized by further comprising:

the two clapboards (8) are arranged in total, the two clapboards (8) are fixedly arranged in the delivery box (1), and a placing mechanism (7) is arranged between the two clapboards (8);

the placement mechanism (7), placement mechanism (7) includes brace table (702), brace table (702) fixed mounting is in the inside bottom of delivery box (1), shrink chamber has all been seted up on the both sides in brace table (702) top, and the inside in both sides shrink chamber all fixedly connected with spring (706), both sides the other end of spring (706) all fixedly connected with stopper (705), the activity of the top of brace table (702) has cup jointed storing frame (701), the clamping groove (704) has all been run through to the surface that storing frame (701) is close to the bottom both sides, a plurality of storing groove (703) have all been evenly offered to the surface of storing frame (701) both sides in addition equidistant;

the limiting blocks (705) on two sides are respectively connected with the clamping grooves (704) on two sides in a clamping mode.

2. The delivery package of claim 1, further comprising:

the fixing mechanism (4), the fixing mechanism (4) comprises four supports (401) and barrel sleeves (404), the four supports (401) and barrel sleeves (404) are respectively arranged, the four supports (401) are respectively fixedly installed around the lower surface of the delivery box (1), the bottom of each support (401) is provided with a containing cavity (402), each containing cavity (402) is internally and slidably clamped with a sucker (403), the four barrel sleeves (404) are respectively fixedly installed around the bottom of the interior of the delivery box (1), threaded rods (406) are respectively inserted through threads on the upper surfaces of the four barrel sleeves (404), a rotator (407) is fixedly connected to the top ends of the threaded rods (406), and connecting rods (405) are fixedly connected to the bottom ends of the threaded rods (406);

the bottom of the connecting rod (405) penetrates through the bottom of the inside of the birth control box (1) and extends to the inside of the storage cavity (402), and the bottom of the connecting rod (405) is fixedly connected with the surface of one side of the sucker (403).

3. The delivery package of claim 1, further comprising:

the delivery box (1), the upper end of the delivery box (1) is provided with a sealing cover (2);

sealing cover (2), sealing cover (2) include apron (201) and mounting bracket (204), the fixed surface of apron (201) one side is connected with changes board (203), it is provided with two respectively to change board (203) and mounting bracket (204) the equal fixed mounting of mounting bracket (204) is on the surface of the outside of delivery box (1), two change board (203) and two mounting bracket (204) are all connected through the pivot, apron (201) is close to the fixed surface of delivery box (1) one side and is connected with rubber pad (202).

4. A delivery package as set forth in claim 3, further comprising:

the delivery box (1), the locking discs (9) are fixedly connected to the periphery of the upper surface of the delivery box (1), and locking holes (10) are formed in the upper surface of each locking disc (9) in a penetrating manner;

the sealing cover (2), the upper surface of the sealing cover (2) is provided with locking mechanisms (3) all around;

the locking mechanism (3), the locking mechanism (3) comprises a locking rod (301), the locking rod (301) is rotationally inserted on the surface of the cover plate (201), a screwing device (302) is fixedly connected to the top end of the locking rod (301), and a locking block (303) is fixedly connected to the bottom end of the locking rod (301);

the locking block (303) is matched with the locking hole (10) in shape and size, and the locking block (303) is connected with the locking hole (304) in an inserting mode.

5. The delivery package of claim 1, further comprising:

the delivery box (1), the surface of one side of the outer part of the delivery box (1) is provided with a carrying mechanism (6), and the carrying mechanism (6) is positioned on the same side of the mounting frame (204);

the backpack mechanism (6), backpack mechanism (6) include backplate (601), backplate (601) fixed mounting is on the surface of delivery box (1), the fixed surface of backplate (601) one side of keeping away from delivery box (1) is connected with braces (602), braces (602) are provided with two altogether.

6. A delivery package as set forth in claim 3, further comprising:

the sealing cover (2), the upper surface of sealing cover (2) fixed mounting has pull ring (5).

7. The delivery package of claim 5, further comprising: and the surface of the back plate (601) far away from one side of the delivery box (1) is provided with a curved surface which is concave inwards.