An external thread length measuring device with adjustable coplanar reference

Abstract

The utility model belongs to length measurement technical field provides a kind of outer thread length measuring device with adjustable coplanar reference, including shell, axial displacement sensing unit and adjustable reference mechanism, adjustable reference mechanism includes fixed base, multiple linkage execution mechanism, driving ring and knob.Fixed base is fixed on shell, and the through-hole that is passed by the thread to be measured is equipped in the center.Each linkage execution mechanism is arranged around through-hole, and two ends are connected with fixed base and driving ring respectively;Driving ring is rotatably sleeved on fixed base, and is transmissionally connected with knob.When rotating knob, driving ring drives each linkage execution mechanism synchronous radial movement, so that its working end forms the annular reference surface of coplanar in closed state, while the central hole diameter enclosed by each linkage execution mechanism changes continuously, adapts the small diameter part of the thread segment end to be measured on the part to be measured.The measuring device is simple in structure, high in precision, does not need power supply, and is suitable for on-site rapid detection.

Description

Technical Field

[0001] This utility model belongs to the field of length measurement technology, and relates to a mechanical special measuring device for high-precision, non-destructive measurement of the effective length of external threads, specifically a device for measuring the length of external threads with an adjustable coplanar reference. Background Technology

[0002] The effective length of an external thread is a key parameter in mechanical manufacturing, assembly, and quality inspection, directly affecting connection strength and sealing performance. Currently, commonly used measurement methods mainly include the following categories: Manual measurement with vernier calipers or micrometers: The operator visually estimates the position of the thread termination point based on experience, and then measures the distance from the starting point to that point. This method is highly subjective, has poor repeatability, and is difficult to accurately locate the thread root (minor diameter). The measurement error is usually greater than ±0.3 mm, which cannot meet the requirements of precision assembly (such as aerospace and hydraulic joints) for ±0.05 mm or even higher precision.

[0003] Optical projectors or image measuring instruments: Although they can magnify and observe the thread profile, they are expensive, bulky, require professional operation, and are sensitive to reflections and oil stains on the thread surface, making them unsuitable for rapid on-site inspection in the workshop.

[0004] Coordinate measuring machine (CMM): High precision, but low efficiency and high cost. It is only suitable for laboratory sampling inspection and cannot be used for mass production process control.

[0005] Special thread gauges or no-go gauges: can only determine whether the length is up to standard, but cannot provide specific values ​​and do not have quantitative measurement functions.

[0006] More critically, existing tools generally lack the ability to automatically locate the minor diameter portion of the thread termination. Since chamfers, end teeth, or burrs often exist at the thread termination point, manual judgment of the reference surface is prone to deviation, leading to distorted measurement results. Furthermore, the minor diameter varies significantly between different thread specifications (such as M6–M30), requiring frequent replacement of parts with poorly versatile measuring tools, thus impacting efficiency.

[0007] Therefore, there is an urgent need for a special device that is simple in structure, easy to operate, can automatically form a coplanar reference surface, has a continuously adjustable center hole diameter, is compatible with various thread specifications, and can achieve high-precision measurement at the ±0.01 mm level in ordinary workshop environments. Utility Model Content

[0008] To address the technical problem that existing measuring tools lack the ability to automatically locate the minor diameter of the thread termination end, resulting in distorted measurement results, this utility model discloses an external thread length measuring device with an adjustable coplanar reference. This device can automatically form a coplanar annular reference surface that fits with the minor diameter of the thread termination end through a mechanical linkage mechanism, and simultaneously adjust the center hole diameter to adapt to different thread specifications, thereby achieving high-precision, non-destructive, and universal external thread length measurement.

[0009] Specifically, the external thread length measuring device includes a housing, one end of which is provided with an axial displacement sensing unit, and the other end is provided with an adjustable reference mechanism. The adjustable reference mechanism includes a fixed base, multiple linkage actuators, a drive ring, and a knob.

[0010] The fixed base is fixed to the housing, and its center has a through hole through which the threaded section of the part to be measured passes; each of the linkage actuators is arranged around the through hole, one end of which is rotatably connected to the fixed base, and the other end is rotatably connected to the drive ring; the drive ring is rotatably fitted on the fixed base and is connected to the knob in a transmission manner. When the knob is rotated, the drive ring drives each of the linkage actuators to move radially in sync, so that their working ends form a coplanar annular reference surface in the closed state. At the same time, the central aperture formed by the linkage actuators changes continuously to adapt to the small diameter part of the end of the thread segment being measured on the part to be measured.

[0011] Furthermore, the linkage actuator includes a blade and a connecting rod. The blade is rotatably connected to the positioning column of the fixed base. One end of the connecting rod is hinged to the blade, and the other end is inserted into the positioning hole circumferentially provided on the drive ring to form a rotatable connection.

[0012] Furthermore, each blade is provided with two light holes, one of which is fitted onto the positioning post of the fixed base, and the other light hole is fitted onto the cylindrical pin at one end of the connecting rod.

[0013] Furthermore, the number of positioning holes circumferentially arranged on the drive ring is equal to the number of connecting rods.

[0014] Furthermore, the blades are fan-shaped, and the number of blades is no less than 4. When all blades move synchronously to the closed position, the working end faces of each blade are on the same plane, and the sides of adjacent blades are in contact with each other, forming a polygonal channel with an adjustable central aperture. This channel is used to accommodate the threaded section on the part to be measured, and to make the minor diameter part of the thread termination contact with the working end face of each blade.

[0015] Furthermore, the adjustable reference mechanism also includes a knob cover, which is fastened to the knob by a standard fastener. The knob cover and the fixed base cooperate to form a rotation limiting structure to limit the rotation angle range of the knob.

[0016] Furthermore, the drive ring and the knob are connected by a plurality of fitting structures. The fitting structure includes a protrusion in the inner cavity of the knob and a semi-circular groove on the outer periphery of the drive ring, and the protrusion is embedded in the semi-circular groove.

[0017] Furthermore, the axial displacement sensing unit includes a dial indicator, a measuring rod, and a measuring head connected coaxially in sequence.

[0018] Furthermore, the probe has a stepped shaft structure, with its large end face abutting against the starting end face of the threaded section being measured on the part to be measured.

[0019] Furthermore, the side wall of the housing is provided with a viewing window, and the viewing window is provided with a transparent viewing cover.

[0020] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: 1. A linkage actuator is formed by multiple fan-shaped blades surrounding the through hole through which the workpiece is tested. All blades in the linkage actuator can move radially synchronously. In the closed state, their inner end faces naturally form a strictly coplanar annular reference surface, which accurately fits the small diameter part of the thread termination end, completely eliminating human judgment error, and the measurement repeatability is better than ±0.01 mm.

[0021] 2. The linkage actuator achieves stepless radial adjustment under the drive ring, so that the diameter of the through hole can be continuously varied within the range of Φ5–Φ28 mm to adapt to various specifications of test parts (such as standard external threads from M6 to M30) without the need to replace parts.

[0022] 3. The external thread length measuring device is a fully mechanical structure with no electronic components and no power supply required. It is oil-resistant, vibration-resistant, reliable, and durable, making it particularly suitable for harsh environments such as factory workshops and maintenance sites.

[0023] 4. The device is easy to operate and highly efficient, requiring only four steps: zeroing the dial indicator, inserting the thread, rotating the knob, and reading the dial indicator value. A single measurement takes less than 10 seconds, making it suitable for batch testing.

[0024] 5. The device has a dual limit protection function. On the one hand, the rotation angle is limited by the knob cover and the fixed base to prevent the blade from being overloaded and opening or closing excessively, which would cause deformation. On the other hand, the transparent viewing window makes it easy to observe the blade closing status in real time and avoid misoperation.

[0025] 6. The end faces of each blade in the linkage actuator are smooth planes, and the contact pressure is controlled by a manual knob. This will not damage the thread profile and is a non-destructive measurement method suitable for final inspection of finished parts.

[0026] 7. The device adopts a modular design, with blades, connecting rods, and drive rings all being independent and detachable parts, making it easy to maintain and replace them individually after wear, thus reducing operating costs. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of an external thread length measuring device with an adjustable coplanar reference. Figure 2 This is a schematic diagram of an adjustable reference mechanism; Figure 3 This is a schematic diagram showing the installation relationship between the adjustable reference mechanism, the knob, and the drive ring. Figure 4 This is a schematic diagram of the part to be measured; Figure 5 A schematic diagram showing the part to be measured assembled onto the external thread length measuring device; The components include: 1. Dial indicator; 2. Measuring rod; 3. Sealing cover; 4. Measuring head; 5. Housing; 6. Transparent viewing cover; 7. Knob; 71. Protruding post; 8. Connecting rod; 9. Drive ring; 91. Semi-circular groove; 10. Blade; 11. Fixing base; 12. Knob cover; 13. Standard fastener. Detailed Implementation

[0029] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0030] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0032] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0033] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] This utility model provides a device for measuring the length of an external thread with an adjustable coplanar reference. See [link to relevant documentation]. Figure 1 As shown, the external thread length measuring device includes a housing 5. One end of the housing 5 is provided with an axial displacement sensing unit, and the other end is provided with an adjustable reference mechanism. The adjustable reference mechanism includes a fixed base 11, multiple linkage actuators, a drive ring 9, and a knob 7.

[0035] like Figure 1 As shown, the fixed base 11 is fixed on the housing 5, and its center is provided with a through hole through which the threaded section of the part to be measured passes; each of the linkage actuators is arranged around the through hole, one end of which is rotatably connected to the fixed base 11, and the other end is rotatably connected to the drive ring 9; the drive ring 9 is rotatably fitted on the fixed base 11 and is connected to the knob 7 in a transmission connection. When the knob 7 is rotated, the drive ring 9 drives each of the linkage actuators to perform synchronous radial movement, so that their working ends form a coplanar annular reference surface in the closed state. At the same time, the central hole diameter formed by the linkage actuators changes continuously to adapt to the small diameter part of the end of the thread segment being measured on the part to be measured.

[0036] In one embodiment, such as Figure 1 As shown, the housing 5 has a viewing window on its side wall, and a transparent viewing cover 6 is provided on the viewing window. Specifically, the housing 5 can be configured as a cylinder, with a sealing cover 3 for fixing a percentage gauge and a threaded fixing base 11 at both ends, and a viewing window is engraved on its circumferential surface. The size of the viewing window is adapted to the transparent viewing cover 6. The transparent viewing cover 6 is arc-shaped and its size is consistent with the window on the circumferential surface of the housing 5.

[0037] In one embodiment, such as Figure 2 As shown, the linkage actuator includes a blade 10 and a connecting rod 8. The blade 10 is rotatably connected to the positioning post of the fixed base 11. One end of the connecting rod 8 is hinged to the blade 10, and the other end is inserted into the positioning hole circumferentially provided in the drive ring 9, forming a rotatable connection. In implementation, the connecting rod 8 can be configured as a thin-walled cylinder with a diameter of ΦQ at both ends, which are adapted to the drive ring 9 and the blade 10 respectively.

[0038] In one embodiment, such as Figure 2 As shown, each blade 10 is provided with two light holes, one of which is sleeved on the positioning post of the fixed base 11, and the other light hole is sleeved on the cylindrical pin at one end of the connecting rod 8.

[0039] In one embodiment, the number of circumferentially arranged positioning holes on the drive ring 9 is equal to the number of connecting rods. In specific implementations, such as... Figure 2 and Figure 3 As shown, the drive ring 9 is circular, with the same outer dimensions as the large hole in the center of the knob 7. A stepped hole is provided in the center, which is adapted to the shape of the fixed base 11. Five light holes that are adapted to the cylinder of the connecting rod 8 are evenly distributed on the end face.

[0040] In one embodiment, such as Figure 2 As shown, the blades 10 are fan-shaped, with no fewer than four blades. In this invention, five blades 10 are preferably used to form an adjustable reference mechanism. When the five blades 10 move synchronously to the closed position, the working end faces of each blade 10 are located on the same plane, and the sides of adjacent blades 10 are in contact with each other, forming a polygonal channel with an adjustable central aperture. This channel is used to accommodate the threaded section on the part to be measured, and to make the small diameter portion of the thread termination contact with the working end face of each blade 10.

[0041] like Figure 2As shown, in this utility model, five linkage actuators are preferably selected to form an adjustable reference mechanism, that is, five blades 10 are selected. The five blades 10 are tangentially combined in a circular shape. The selected fixed base 11 is a frustum structure with a through hole in the center and steps on the outside. The large end face is evenly distributed with cylinders that are adapted to the holes on the blades 10, and the small end face is provided with external threads that are adapted to the housing 5. The circumferential surface of the thread is provided with two symmetrical planes. The entire end face of the fixed base 11 is a left-right symmetrical structure.

[0042] In one embodiment, such as Figures 1 to 3 As shown, the adjustable reference mechanism also includes a knob cover 12, which is fastened to the knob 7 by a standard fastener 13. The knob cover 12 and the fixed base 11 cooperate to form a rotation limiting structure, which is used to limit the rotation angle range of the knob 7.

[0043] In one embodiment, such as Figure 3 As shown, the drive ring 9 and the knob 7 are connected by multiple interlocking structures. Each interlocking structure includes a protrusion 71 located within the inner cavity of the knob 7 and a semi-circular groove 91 located on the outer periphery of the drive ring 9. The protrusion 71 is embedded in the semi-circular groove 91. Specifically, the outer circumferential surface of the knob 7 is knurled, and a stepped hole is located in the center. The knob 7 has three protrusions 71 on its inner side, evenly distributed along the circumferential direction.

[0044] In one embodiment, such as Figure 1 As shown, the axial displacement sensing unit includes a dial indicator 1, a measuring rod 2, and a measuring head 4, which are coaxially connected in sequence. The dial indicator 1 can be fixed to the upper end of the housing 5 by a sealing cover 3. The sealing cover 3 is frustoconical, with a hole of diameter ΦD at its center that matches the outer diameter of the measuring rod 2. The smaller end has a thread Mc that matches the housing 5, and the larger end has the same outer diameter as the housing 5. The dial indicator 1 can be selected with the appropriate measurement accuracy according to the tolerance being measured. The measuring rod 2 has an outer diameter of D (cylindrical), with a hole of diameter Φd on one end face that matches the dial indicator needle, and a standard thread Ma on the other end face that matches the measuring head 4.

[0045] In one embodiment, the probe 4 is a stepped shaft structure, with its large end face abutting against the starting end face of the threaded segment being measured on the part to be measured. Specifically, the upper small end of the stepped shaft structure is screwed into the hole of the probe 2 and fixed to the probe 2; the lower large end is a plane, abutting against the starting end face of the threaded segment being measured on the part to be measured. More specifically, the upper small end is provided with an external thread MC adapted to the probe 2, and the lower large end has an outer diameter of Φx, which is used to increase the contact area between the end face and the object being measured.

[0046] Before measurement, different measurement reference surfaces can be selected to zero the dial indicator according to the different termination positions of the thread segment to be measured on the part to be measured. In this invention, the inner side of the blade 10 is selected as the measurement reference surface. Then, the knob 7 is rotated so that all the blades 10 are opened to be larger than the major diameter of the thread of the object to be measured. The thread of the object to be measured is inserted into the housing 5 through the hole of the blade 10, and the starting end of the thread is ensured to contact the probe 4 until all the threads have passed through the measurement reference surface. Then, the knob 7 is rotated to the limit position of the minor diameter of the thread to be measured so that the termination end of the thread is in contact with the blade 10. The final reading of the dial indicator 1 is the thread length.

[0047] Using an external thread length measuring device to measure, for example Figure 4 The process of measuring the external thread length on the part to be measured is as follows: First, install dial indicator 1, measuring rod 2 and measuring head 4 on the left end of housing 5, and install adjustable reference mechanism and external thread length measuring device on the right end.

[0048] First, select a reference surface to zero the dial indicator (i.e., zero the dial indicator after the probe contacts the reference surface) to initialize the state; then, turn knob 7 to the open position, and the five fan-shaped blades 10 unfold outwards. Insert the threaded section to be measured on the part to be measured from the right end until its starting end face abuts against the large end face of the probe 4.

[0049] Next, rotate the knob 7 clockwise. Its inner cavity protrusion 71 pushes the semi-circular groove 91 on the outer periphery of the drive ring 9, causing the drive ring 9 to rotate. This pulls the five connecting rods 8, causing the blade 10 to swing synchronously around the positioning post of the fixed base 11.

[0050] Finally, as Figure 5 As shown, when the working end of blade 10 is fully in contact with the minor diameter of the thread termination end, the five end faces are coplanar, forming a reference. At this time, the reading of dial indicator 1 is the effective length of the external thread. The inner protrusion of knob cover 12 cooperates with the two symmetrical planes on the outer periphery of fixed base 11, limiting the rotation angle of knob 7 within ±45°. The blade closure status can be easily observed through the transparent viewing cover 6.

[0051] The embodiments of this utility model achieve the following technical effects: 1. A linkage actuator is formed by multiple fan-shaped blades surrounding the through hole through which the workpiece is tested. All blades in the linkage actuator can move radially synchronously. In the closed state, their inner end faces naturally form a strictly coplanar annular reference surface, which accurately fits the small diameter part of the thread termination end, completely eliminating human judgment error, and the measurement repeatability is better than ±0.01 mm.

[0052] 2. The linkage actuator achieves stepless radial adjustment under the drive ring, so that the diameter of the through hole can be continuously varied within the range of Φ5–Φ28 mm to adapt to various specifications of test parts (such as standard external threads from M6 to M30) without the need to replace parts.

[0053] 3. The external thread length measuring device is a fully mechanical structure with no electronic components and no power supply required. It is oil-resistant, vibration-resistant, reliable, and durable, making it particularly suitable for harsh environments such as factory workshops and maintenance sites.

[0054] 4. The device is easy to operate and highly efficient, requiring only four steps: zeroing the dial indicator, inserting the thread, rotating the knob, and reading the dial indicator value. A single measurement takes less than 10 seconds, making it suitable for batch testing.

[0055] 5. The device has a dual limit protection function. On the one hand, the rotation angle is limited by the knob cover and the fixed base to prevent the blade from being overloaded and opening or closing excessively, which would cause deformation. On the other hand, the transparent viewing window makes it easy to observe the blade closing status in real time and avoid misoperation.

[0056] 6. The end faces of each blade in the linkage actuator are smooth planes, and the contact pressure is controlled by a manual knob. This will not damage the thread profile and is a non-destructive measurement method suitable for final inspection of finished parts.

[0057] 7. This device adopts a modular design; the blades, connecting rods, and drive rings are all independent and detachable components, making maintenance easy and allowing for individual replacement after wear, thus reducing operating costs.

[0058] Obviously, those skilled in the art should understand that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the embodiments of the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for measuring the length of an external thread with an adjustable coplanar reference, characterized in that, Includes a housing (5), one end of which is provided with an axial displacement sensing unit, and the other end is provided with an adjustable reference mechanism. The adjustable reference mechanism includes a fixed base (11), multiple linkage actuators, a drive ring (9), and a knob (7). The fixed base (11) is fixed on the housing (5), and its center is provided with a through hole through which the threaded section of the part to be measured passes; each of the linkage actuators is arranged around the through hole, one end of which is rotatably connected to the fixed base (11), and the other end is rotatably connected to the drive ring (9); the drive ring (9) is rotatably fitted on the fixed base (11) and is connected to the knob (7) in a transmission connection; When the knob (7) is rotated, the drive ring (9) drives each of the linkage actuators to perform synchronous radial movement, so that their working ends form a coplanar annular reference surface in the closed state. At the same time, the central hole diameter formed by the linkage actuators changes continuously to match the small diameter part of the end of the thread segment being measured on the part to be measured.

2. The external thread length measuring device with adjustable coplanar reference according to claim 1, characterized in that, The linkage actuator includes a blade (10) and a connecting rod (8). The blade (10) is rotatably connected to the positioning column of the fixed base (11). One end of the connecting rod (8) is hinged to the blade (10), and the other end is inserted into the positioning hole circumferentially provided on the drive ring (9) to form a rotatable connection.

3. The external thread length measuring device with adjustable coplanar reference according to claim 2, characterized in that, Each blade (10) is provided with two light holes, one of which is fitted on the positioning post of the fixed base (11), and the other light hole is fitted on the cylindrical pin at one end of the connecting rod (8).

4. The external thread length measuring device with adjustable coplanar reference according to claim 2, characterized in that, The number of positioning holes circumferentially set on the drive ring (9) is equal to the number of connecting rods.

5. The external thread length measuring device with an adjustable coplanar reference according to any one of claims 2 to 4, characterized in that, The blade (10) is fan-shaped and has no fewer than 4 blades; When all blades (10) move synchronously to the closed position, the working end faces of each blade (10) are on the same plane, and the sides of adjacent blades (10) are in contact with each other, forming a polygonal channel with an adjustable central aperture. This channel is used to accommodate the threaded section on the part to be measured, and to make the small diameter part of the thread termination end contact the working end face of each blade (10).

6. The external thread length measuring device with adjustable coplanar reference according to claim 1, characterized in that, The adjustable reference mechanism also includes a knob cover (12), which is fastened to the knob (7) by a standard fastener (13). The knob cover (12) and the fixed base (11) cooperate to form a rotation limiting structure to limit the rotation angle range of the knob (7).

7. The external thread length measuring device with adjustable coplanar reference according to claim 1, characterized in that, The drive ring (9) and the knob (7) are connected by a plurality of fitting structures. The fitting structure includes a protrusion (71) in the inner cavity of the knob (7) and a semi-circular groove (91) on the outer periphery of the drive ring (9). The protrusion (71) is embedded in the semi-circular groove (91).

8. The external thread length measuring device with adjustable coplanar reference according to claim 1, characterized in that, The axial displacement sensing unit includes a dial indicator (1), a measuring rod (2), and a measuring head (4) connected coaxially in sequence.

9. The external thread length measuring device with adjustable coplanar reference according to claim 8, characterized in that, The probe (4) has a stepped shaft structure, and its large end face abuts against the starting end face of the threaded section to be measured on the part to be measured.

10. The external thread length measuring device with adjustable coplanar reference according to claim 1, characterized in that, The housing (5) has a viewing window on its side wall, and a transparent viewing cover (6) is provided on the viewing window.

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