Transmission structure of centerless indentation cutting device

Abstract

The utility model relates to the technical field of paperboard processing equipment, in particular to a transmission structure of a centerless creasing and cutting device, which comprises a mounting support, a creasing mechanism and a cutting mechanism, the creasing mechanism and the cutting mechanism are respectively arranged on the mounting support, the creasing mechanism comprises a connecting plate and a creasing rotating wheel, and the connecting plate is connected with the creasing rotating wheel. The creasing rotating wheel is arranged outside the connecting plate, one end of the connecting plate is hinged to the mounting support, a supporting cross beam is arranged at the bottom of the mounting support, a first pushing air cylinder is arranged on the supporting cross beam, the power output end of the first pushing air cylinder is hinged to the other end of the connecting plate, and a second pushing air cylinder is arranged at the top of the connecting plate. The cutting mechanism is arranged at the bottom of the connecting plate, and the power output end of the second pushing and pressing air cylinder is hinged to the cutting mechanism, so that integration of creasing and cutting is effectively achieved, transmission stability and stress uniformity are guaranteed, and the conditions that creases are shallow and a cutter is broken are prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of cardboard processing equipment, in particular to a transmission structure of a centerless indentation cutting device. Background Art

[0002] Cartons are the most widely used packaging products, and packaging cartons are an indispensable part of modern logistics. Commonly used packaging cartons are mainly corrugated boxes and single-layer cardboard boxes. Both corrugated boxes and single-layer cardboard boxes are made by cutting and creasing cardboard, then folding and gluing them into the box shape.

[0003] In the existing cardboard processing, the cutting and creasing of cardboard are related to the quality of carton production. In the existing cutting process, a cutting blade is mostly used to cut the cardboard into a certain size, and in the existing creasing process, an indentation is made on the surface of the cardboard to facilitate the cardboard to be folded into a carton along the indentation. If the cardboard is cut and creasing manually, it is easy to cause high labor costs and low work efficiency. Although the existing cardboard processing equipment can improve work efficiency compared with manual cutting and creasing, the existing cardboard processing equipment can only perform cutting and creasing actions on the cardboard separately, and cannot perform cutting and creasing actions at the same time. In the cutting process, the cutting blade is prone to blade shaking due to uneven force and excessive transmission load, resulting in blade breakage. If the creasing blade is unevenly stressed during the creasing process, the carton fold will be shallow, affecting the subsequent carton folding and affecting the carton production efficiency.

[0004] Reference patent publication number is "CN206493624U", and the patent name is "A cutting and creasing integrated device for a carton customization machine". The technical solution discloses "A cutting and creasing integrated device for a carton customization machine, comprising a connecting frame, the bottom of the connecting frame is horizontally connected to a horizontal support plate, one end of the horizontal support plate is vertically connected to a vertical support plate, the inner sides of the horizontal support plate and the vertical support plate together constitute an installation interval, and the installation interval is provided with a creasing cylinder, a cutting cylinder, two creasing wheel rims and a cutting blade, one end of the creasing cylinder is connected to the other end of the horizontal support plate, and the other end of the vertical support plate is vertically connected to the vertical support plate. The end of the wheel is movably connected to an auxiliary pressing arm, the other end of the auxiliary pressing arm is connected to the other end of the creasing cylinder, the auxiliary pressing arm is rotatably connected to a swing block, the other end of the cutting cylinder is rotatably connected to one end of the swing block, the cutting blade is installed at the other end of the swing block, and the cutting blade partially extends into the creasing groove. Although this technical solution can realize the integration of the cutting and creasing processes of the carton through the integrated cutting and creasing device, it cannot overcome the problem that when the cylinder transmission drives the creasing wheel rim and the cutting blade during creasing and cutting of the cardboard, the load is too large, resulting in uneven force and unstable transmission, and the accuracy of cardboard cutting and creasing cannot be ensured.

[0005] Therefore, how to achieve transmission stability and force uniformity during automatic cutting and creasing is the main technical problem currently faced by technicians. Utility Model Content

[0006] The purpose of the present invention is to provide a transmission structure of a centerless indentation cutting device, which solves the problems raised in the above background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A transmission structure of a centerless indentation cutting device, comprising:

[0009] Mounting bracket, creasing mechanism and cutting mechanism;

[0010] The mounting bracket is provided with an indentation mechanism and a cutting mechanism, respectively, and the indentation mechanism includes a connecting plate and an indentation wheel, the indentation wheel is provided on the outside of the connecting plate, one end of the connecting plate is hinged to the mounting bracket, and a supporting beam is provided at the bottom of the mounting bracket, the supporting beam is provided with a first pushing cylinder, and the power output end of the first pushing cylinder is hinged to the other end of the connecting plate;

[0011] A second pushing cylinder is provided on the top of the connecting plate, and the cutting mechanism is provided on the bottom of the connecting plate. The power output end of the second pushing cylinder is hinged on the cutting mechanism. The first pushing cylinder is used to control the range of movement of the indentation mechanism, and the second pushing cylinder is used to control the range of movement of the cutting mechanism.

[0012] Preferably, both ends of the bottom of the connecting plate are provided with downward pressure rollers, the top of the connecting plate is provided with a support plate, the top of the support plate is provided with a limiting roller, the bottom of the support plate is abutted against the top of the connecting plate, and the downward pressure roller and the limiting roller are both located inside the indentation wheel.

[0013] Preferably, the power output end of the first pushing cylinder and the power output end of the second pushing cylinder are both provided with a ball shaft, and the connecting plate and the cutting mechanism are both provided with an arc groove for the ball shaft to be placed in.

[0014] Preferably, the cutting mechanism includes a movable plate, one end of the movable plate is hinged to the bottom of the connecting plate, the power output end of the second pushing cylinder is hinged to the other end of the movable plate, and a cutting saw blade is provided on the outside of the movable plate.

[0015] Preferably, the pressing roller is symmetrically arranged at the bottom of the connecting plate, and the two pressing rollers and the limiting roller are distributed in a triangular array inside the indentation wheel, and the outer walls of the two pressing rollers and the limiting roller are tangent to the inner wall of the indentation wheel.

[0016] Preferably, the creasing wheel includes two annular plates, the two annular plates are arranged to overlap each other, and the cutting saw blade is located between the two annular plates.

[0017] Preferably, the supporting beam is further provided with a mounting opening, the mounting opening is aligned with the supporting plate, and the supporting plate is passed through the interior of the mounting opening.

[0018] Compared with the prior art, the present technical solution provides a transmission structure of a centerless creasing and cutting device: by providing a mounting bracket, a connecting plate, a creasing mechanism and a cutting mechanism, by respectively providing a creasing mechanism and a cutting mechanism on the mounting bracket, by the creasing mechanism including a connecting plate and a creasing wheel, the creasing wheel is provided on the outside of the connecting plate, and one end of the connecting plate is hinged on the mounting bracket, by providing a supporting crossbeam at the bottom of the mounting bracket, and by providing a first pushing cylinder on the supporting crossbeam, the power output end of the first pushing cylinder is hinged to the other end of the connecting plate, so that the first pushing cylinder drives the connecting plate to move, and the connecting plate drives the creasing wheel to press down, and the creasing wheel performs a rolling creasing action on the cardboard, and by providing a second pushing cylinder on the top of the connecting plate, The cutting mechanism is also arranged at the bottom of the connecting plate and is hinged to the cutting mechanism through the power output end of the second pushing cylinder, so that the second pushing cylinder drives the cutting mechanism. The first pushing cylinder can be used to control the range of motion of the indentation mechanism, and the second pushing cylinder can also be used to control the range of motion of the cutting mechanism. Moreover, since the power output end of the first pushing cylinder and the power output end of the second pushing cylinder are both driven by an articulated connection, the axial motion can be converted into a curved motion. Therefore, the transmission stability can be improved during the downward pressing process, and the articulated transmission can play a role of parallel axial force to achieve uniform force, thereby reducing the load of axial movement, effectively realizing the integration of indentation and cutting, and ensuring the stability of transmission and uniform force, preventing shallow creases and chipping. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0021] Figure 2 This is a schematic diagram of the overall structure of the utility model from another perspective

[0022] Figure 3 It is a structural schematic diagram of the connecting plate and the cutting mechanism in the utility model.

[0023] Figure 4 It is a schematic diagram of the structure of the ball head shaft in the utility model.

[0024] Figure 5 It is a schematic diagram of the structure of the indentation wheel in the utility model.

[0025] As shown in the figure: 1. Mounting bracket; 2. Indentation mechanism; 3. Cutting mechanism; 4. Support plate; 10. Support beam; 21. Connecting plate; 22. Indentation wheel; 31. Movable plate; 32. Cutting saw blade; 41. Limiting roller; 99. Ball head shaft; 100. Arc groove; 101. First pushing cylinder; 102. Mounting opening; 210. Second pushing cylinder; 211. Pressing roller; 221. Annular plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary persons in this field without making creative work are within the scope of protection of the present invention. The preferred embodiments of the present invention will be described in more detail below with reference to the drawings. Although the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described here. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0027] The terms used in this utility model are for the purpose of describing specific embodiments only and are not intended to limit the utility model. As used in this utility model and the appended claims, the singular forms "a," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0028] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0029] In the description of the present invention, it should be understood that the terms "thickness", "up", "down", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0031] It should be understood that although the terms "first", "second", "third", etc. may be used to describe various components in the present invention, this information should not be limited to these terms. These terms are only used to distinguish components of the same type from each other. For example, without departing from the scope of the present invention, the first component may also be referred to as the second component, and similarly, the second component may also be referred to as the first component. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0032] The technical solutions of the embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0033] refer to Figures 1 to 5 , a transmission structure of a centerless indentation cutting device, comprising:

[0034] Install the bracket 1, the indentation mechanism 2 and the cutting mechanism 3;

[0035] The mounting bracket 1 is provided with a creasing mechanism 2 and a cutting mechanism 3, respectively, and the creasing mechanism 2 includes a connecting plate 21 and a creasing wheel 22, the creasing wheel 22 is provided on the outside of the connecting plate 21, one end of the connecting plate 21 is hinged to the mounting bracket 1, and a supporting beam 10 is provided at the bottom of the mounting bracket 1, and a first pushing cylinder 101 is provided on the supporting beam 10, and the power output end of the first pushing cylinder 101 is hinged to the other end of the connecting plate 21;

[0036] A second pushing cylinder 210 is provided at the top of the connecting plate 21, and the cutting mechanism 3 is provided at the bottom of the connecting plate 21. The power output end of the second pushing cylinder 210 is hinged on the cutting mechanism 3. The first pushing cylinder 101 is used to control the range of movement of the creasing mechanism 2, and the second pushing cylinder 210 is used to control the range of movement of the cutting mechanism 3.

[0037] Specifically, both ends of the bottom of the connecting plate 21 are provided with downward pressure rollers 211, the top of the connecting plate 21 is provided with a support plate 4, and the top of the support plate 4 is provided with a limiting roller 41. The bottom of the support plate 4 is in contact with the top of the connecting plate 21, and the downward pressure roller 211 and the limiting roller 41 are both located inside the indentation wheel 22.

[0038] Specifically, the power output ends of the first pushing cylinder 101 and the second pushing cylinder 210 are both provided with ball shafts 99 , and the connecting plate 21 and the cutting mechanism 3 are both provided with arc grooves for the ball shafts 99 to be placed in.

[0039] Specifically, the cutting mechanism 3 includes a movable plate 31, one end of the movable plate 31 is hinged to the bottom of the connecting plate 21, the power output end of the second pushing cylinder 210 is hinged to the other end of the movable plate 31, and a cutting saw blade 32 is provided on the outside of the movable plate 31.

[0040] Specifically, the pressing roller 211 is symmetrically arranged at the bottom of the connecting plate 21, and the two pressing rollers 211 and the limiting roller 41 are distributed in a triangular array inside the indentation wheel 22, and the outer walls of the two pressing rollers 211 and the limiting roller 41 are tangent to the inner wall of the indentation wheel 22.

[0041] Specifically, the creasing wheel 22 includes two annular plates 221 . The two annular plates 221 are overlapped with each other, and the cutting saw blade 32 is located between the two annular plates 221 .

[0042] Specifically, the support beam 10 is further provided with a mounting opening 102 , the mounting opening 102 is aligned with the support plate 4 , and the support plate 4 is passed through the interior of the mounting opening 102 .

[0043] Example 1

[0044] In order to realize the automatic creasing action on the cardboard, the cardboard needs to be creasing during the cardboard processing process, and the cardboard surface needs to be creasing to form creases, so that the cardboard can be folded along the folding groove to form a carton. During the creasing process of the cardboard, the force is ensured to be uniform so that the depth of the crease is uniform. This embodiment includes: by providing a mounting bracket 1, a creasing mechanism 2 and a cutting mechanism 3, and by respectively providing a creasing mechanism 2 and a cutting mechanism 3 on the mounting bracket 1; wherein the creasing mechanism 2 includes a connecting plate 21 and a creasing wheel 22, and the creasing wheel 22 is provided on the outside of the connecting plate 21, and one end of the connecting plate 21 is hinged to the mounting bracket 1, and by providing a supporting beam 10 at the bottom of the mounting bracket 1, and by providing a supporting beam 10 on the supporting beam 10 A first pushing cylinder 101 is provided on it. By hingedly connecting the power output end of the first pushing cylinder 101 to the other end of the connecting plate 21, the first pushing cylinder 101 is used to control the range of motion of the indentation mechanism 2. The first pushing cylinder 101 drives the clamping mechanism to perform indentation on the cardboard. When the first pushing cylinder 101 drives the indentation mechanism 2, smooth transmission is achieved, thereby reducing the transmission load. Therefore, the downward pressing axial force of the first pushing cylinder 101 is converted into a curved motion force, thereby reducing the force load and achieving a smooth transmission effect, preventing the transmission force load from being too large, resulting in uneven force on the indentation mechanism 2 and the cutting mechanism 3, resulting in position offset or shaking, affecting the accuracy of the cardboard during indentation and cutting.

[0045] It should be noted that, in this embodiment, in order to realize that the mounting bracket 1 supports the indentation wheel 22 and has the effect of uniform force on the indentation wheel 22, a mounting bracket 1, an indentation mechanism 2 and a cutting mechanism 3 are provided, an indentation mechanism 2 and a cutting mechanism 3 are respectively provided on the mounting bracket 1, a pressing roller 211 is provided at both ends of the bottom of the connecting plate 21, a supporting plate 4 is provided on the top of the connecting plate 21, and a limiting roller 41 is provided on the top of the supporting plate 4, the bottom of the supporting plate 4 is abutted against the top of the connecting plate 21, and the pressing roller 211 and the limiting roller 41 are both located inside the indentation wheel 22; wherein, by symmetrically arranging the pressing roller 211 on the connecting plate 2 1, and the two pressing rollers 211 and the limiting roller 41 are distributed in a triangular array inside the indentation wheel 22, and the outer walls of the two pressing rollers 211 and the limiting roller 41 are tangent to the inner wall of the indentation wheel 22, so that the pressing roller 211 and the limiting roller 41 support the indentation wheel 22, and the triangular array is distributed inside the indentation wheel 22 to achieve the effect of uniform force, thereby achieving that when the first pushing mechanism drives the connecting plate 21 to press down, the two pressing rollers 211 at the bottom of the connecting plate 21 drive the indentation wheel 22 to press down, and because the two pressing rollers 211 and the limiting roller 41 are tangent to the inner wall of the indentation wheel 22, the indentation wheel 22 rotates and indents.

[0046] It is particularly noted that by providing an installation opening 102 on the support beam 10, aligning the installation opening 102 with the support plate 4, and inserting the support plate 4 into the interior of the installation opening 102, it is facilitated to install the support plate 4, and the limiting roller 41 of the support plate 4 plays a role of limiting support for the top of the indentation wheel 22.

[0047] Example 2

[0048] In order to realize automatic cutting of cardboard, in the process of processing cardboard into carton, cardboard needs to be cut to a certain size, and when the cutting saw blade 32 presses down to cut the cardboard, it is necessary to ensure that the force load on the cutting saw blade 32 is not overloaded to prevent the cutting saw blade 32 from shaking and breaking. This embodiment includes: a second pushing cylinder 210 is provided on the top of the connecting plate 21, the cutting mechanism 3 is provided at the bottom of the connecting plate 21, and the power output end of the second pushing cylinder 210 is hinged to the cutting mechanism 3, and the cutting mechanism 3 includes a movable plate 31, and one end of the movable plate 31 is hinged to the bottom of the connecting plate 21. The second pushing cylinder 210 is hinged to the other end of the movable plate 31 by the power output end of the second pushing cylinder 210. The cutting saw blade 32 is provided on the outside of the movable plate 31. Therefore, when the second pushing cylinder 210 drives the other end of the movable plate 31, the other end of the movable plate 31 moves downward, so that the movable plate 31 drives the cutting saw blade 32 to press down, thereby realizing the cutting saw blade 32 to cut the cardboard. Since one end of the movable plate 31 is hinged to the bottom of the connecting plate 21, the connecting plate 21 can play a connecting and supporting role for the movable plate 31, so that the cutting saw blade 32 can be tangent to the surface of the cardboard for cutting.

[0049] It should be noted that, with respect to this embodiment, further supplementary explanation is required. To further ensure that the cutting saw blade 32 does not shake, the indentation wheel 22 includes two annular plates 221, and the two annular plates 221 are arranged to overlap each other, and the cutting saw blade 32 is located between the two annular plates 221. Therefore, the two annular plates 221 can be used to clamp and limit the cutting saw blade 32, ensuring that the cutting saw blade 32 does not shake to a large extent and cause chipping. When the movable plate 31 is lowered, the cutting saw blade 32 can be extended from between the two annular plates 221 to cut the cardboard.

[0050] In combination with the above embodiments, it is further supplemented that the first pushing cylinder 101 and the second pushing cylinder 210 can be respectively connected to the indentation mechanism 2 and the cutting mechanism 3 in the following hinged manner, and the power output end of the first pushing cylinder 101 and the power output end of the second pushing cylinder 210 can be provided with a ball head shaft 99, and the connecting plate 21 and the cutting mechanism 3 are provided with an arc groove 100 for the ball head shaft 99 to be placed. Therefore, when the first pushing cylinder 101 is pressed down, the ball head shaft 99 drives the connecting plate 21, and when the second pushing cylinder 210 is pressed down, the ball head shaft 99 drives the cutting mechanism 3, and rotates along the ball head shaft 99 through the arc groove 100, thereby achieving uniform force, realizing the conversion of axial motion into curved motion, improving transmission smoothness, and preventing the uneven force on the indentation wheel 22 due to excessive transmission load, affecting the depth of the fold, and preventing the cutting saw blade 32 from shaking due to uneven force and causing the knife to break.

[0051] The scheme of the present invention has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have their own emphases. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for the present invention. In addition, it can be understood that the steps in the method of the embodiment of the present invention can be adjusted in sequence, merged and deleted according to actual needs, and the structures in the device of the embodiment of the present invention can be merged, divided and deleted according to actual needs.

[0052] While various embodiments of the present invention have been described above, the above descriptions are illustrative and non-exhaustive, and are not intended to be limiting of the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A transmission structure of a centerless creasing cutting device, characterized in that: include: Install the bracket, creasing mechanism and cutting mechanism; The mounting bracket is provided with an indentation mechanism and a cutting mechanism respectively, and the indentation mechanism includes a connecting plate and an indentation wheel, the indentation wheel is arranged outside the connecting plate, one end of the connecting plate is hinged on the mounting bracket, and a supporting crossbeam is arranged at the bottom of the mounting bracket, a first pushing cylinder is arranged on the supporting crossbeam, and a power output end of the first pushing cylinder is hinged on the other end of the connecting plate; A second pushing cylinder is arranged on the top of the connecting plate, and the cutting mechanism is arranged on the bottom of the connecting plate, the power output end of the second pushing cylinder is hinged on the cutting mechanism, the first pushing cylinder is used to control the movable range of the creasing mechanism, and the second pushing cylinder is used to control the movable range of the cutting mechanism.

2. The transmission structure of the centerless creasing cutting device according to claim 1, characterized in that: Both ends of the bottom of the connecting plate are provided with pressing rollers, the top of the connecting plate is provided with a supporting plate, the top of the supporting plate is provided with a limiting roller, the bottom of the supporting plate is abutted against the top of the connecting plate, and the pressing roller and the limiting roller are both located inside the indentation wheel.

3. The transmission structure of the centerless creasing cutting device according to claim 1, characterized in that: The power output ends of the first pushing cylinder and the second pushing cylinder are both provided with ball head shafts, and the connecting plate and the cutting mechanism are both provided with arc grooves for the ball head shafts to be placed in.

4. The transmission structure of the centerless creasing cutting device according to claim 1, characterized in that: The cutting mechanism comprises a movable plate, one end of which is hinged to the bottom of the connecting plate, the power output end of the second pushing cylinder is hinged to the other end of the movable plate, and a cutting saw blade is arranged outside the movable plate.

5. The transmission structure of the centerless creasing cutting device according to claim 2, characterized in that: The pressing rollers are symmetrically arranged at the bottom of the connecting plate, and the two pressing rollers and the limiting rollers are distributed in a triangular array inside the indentation wheel, and the outer walls of the two pressing rollers and the limiting rollers are tangent to the inner wall of the indentation wheel.

6. The transmission structure of the centerless creasing cutting device according to claim 4, characterized in that: The creasing wheel comprises two annular plates, the two annular plates are arranged to overlap each other, and the cutting saw blade is located between the two annular plates.

7. The transmission structure of the centerless creasing cutting device according to claim 2, characterized in that: The supporting crossbeam is also provided with a mounting opening, the mounting opening is aligned with the supporting plate, and the supporting plate is passed through the interior of the mounting opening.

Images