A highway guardrail auxiliary support device
By designing an auxiliary support device for highway guardrails, using clamps and support legs to fix the posts, and combining a level and positioning unit, the problem of post displacement during construction was solved, improving installation efficiency and convenience.
Patent Information
- Application Number
- CN202522248421.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-24
- Publication Date
- 2026-11-06
- Estimated Expiration
- 2035-10-24
AI Technical Summary
In the existing highway guardrail installation process, the posts are prone to shifting due to construction disturbances after being adjusted to a vertical position, requiring construction workers to make multiple adjustments, increasing labor intensity and reducing installation efficiency.
An auxiliary support device for highway guardrails was designed, including a clamping component, a level, support legs, and a positioning unit. The clamping component fixes the column, the support legs are connected to the foundation, the level ensures the column is vertical, and the positioning unit stabilizes the position of the column.
It effectively maintains the verticality of the columns, reduces the number of adjustments required by construction workers, and improves installation efficiency and ease of construction.
Smart Images

Figure CN224943069U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of highway guardrail installation technology, and in particular to an auxiliary support device for highway guardrails. Background Technology
[0002] Highway guardrails are crucial facilities for ensuring road traffic safety. They mainly consist of five core components: guardrail panels, posts, anti-collision blocks, end caps, and fasteners. The wavy guardrail panels serve as the primary energy-absorbing and guiding surface; the posts act as a supporting framework, transferring impact force to the foundation; the anti-collision blocks in the middle effectively buffer and prevent wheel obstruction; the end caps at both ends eliminate the risk of punctures, ensuring a safe finish; and finally, high-strength fasteners securely connect all components, working together to play a crucial role in buffering, guiding, and protecting, thus ensuring road traffic safety.
[0003] During the construction of highway guardrails, in order to ensure that the posts can effectively resist impact, they must be strictly buried vertically. However, during the installation of the posts, after the construction workers adjust the posts to be vertical, due to the lack of effective temporary fixing measures, they are very prone to displacement when backfilling or when disturbed by surrounding construction. This displacement forces the workers to make repeated adjustments, which not only significantly increases the labor intensity, but also seriously slows down the overall installation efficiency of the guardrail. Utility Model Content
[0004] Therefore, the technical problem to be solved by this utility model is that it is not easy to ensure the verticality of the existing highway guardrail installation, which requires construction personnel to make repeated adjustments, which is time-consuming and labor-intensive.
[0005] The above-mentioned technical problems are solved by the following technical solution: This utility model proposes an auxiliary support device for highway guardrails, which includes a clamping member, the clamping member covering the outside of the column; A level is fixedly installed on the upper surface of the clamping member; The support legs are provided in multiple sets, and the multiple sets of support legs are equidistantly distributed around the outer wall of the clamping member. The positioning unit includes a connecting sleeve fixedly installed on the outside of the support leg, a set of semi-threaded sleeves arranged opposite each other on the inside of the connecting sleeve, a button for pushing the set of semi-threaded sleeves closer to each other, and a pressure rod for pushing the set of semi-threaded sleeves further apart. The screw is threadedly engaged with the semi-threaded sleeve; The inner wall of the support plate abuts against the outer wall of the column.
[0006] In a preferred embodiment of the highway guardrail auxiliary support device of this utility model: the number of connecting sleeves includes a first kit and a second kit, the first kit and the second kit are arranged opposite to each other and connected by bolts; The axis of the semi-threaded sleeve is perpendicular to the axis of the support leg.
[0007] In a preferred embodiment of the auxiliary support device for highway guardrails described in this utility model: the semi-threaded sleeve includes a slider, a baffle fixedly connected to the slider, and a guide post coaxially arranged with the support leg; The first and second kits cooperate to form a limiting groove that is compatible with the slider; A set of the semi-threaded sleeves can be positioned along the axis of the support leg.
[0008] In a preferred embodiment of the auxiliary support device for highway guardrails of this utility model: a positioning sleeve is provided on the outer side of the button, and the positioning sleeve is fixedly connected to the connecting sleeve; The button includes a guide plate and a spring disposed inside the button; One end of the spring is connected to the button, and the other end abuts against the outer wall of the connecting sleeve.
[0009] In a preferred embodiment of the auxiliary support device for highway guardrails of this utility model: a first pressure block is provided on one side of the baffle, and the first pressure block is fixedly connected to the baffle; A second pressure block is provided on the inner side of the guide plate, and the second pressure block is fixedly connected to the guide plate. The second pressure block abuts against the first pressure block, which can push a set of the semi-threaded sleeves to abut against each other.
[0010] In a preferred embodiment of the highway guardrail auxiliary support device of this utility model: the pressure rod is fixedly connected to the button, and the pressure rod moves synchronously with the button; The pressure bar includes a pressing portion disposed at its end; The second pressure block is offset from the first pressure block, and the bottom of the pressure rod abuts against the top of the baffle.
[0011] In a preferred embodiment of the highway guardrail auxiliary support device of this utility model: the pressing part abuts against the side wall of the baffle, and the downward movement of the pressure rod can push a group of semi-threaded sleeves away from each other; The screw is disengaged from the semi-threaded sleeve, allowing the screw to be fed in quickly.
[0012] In a preferred embodiment of the auxiliary support device for highway guardrails described in this utility model: the bottom of the support leg is connected to a ground nail via a universal joint.
[0013] In a preferred embodiment of the auxiliary support device for highway guardrails described in this utility model: the clamping member includes a first clamp and a second clamp, which are hinged together.
[0014] In a preferred embodiment of the auxiliary support device for highway guardrails described in this utility model, the length of the support leg is adjustable.
[0015] The beneficial effects of this utility model are as follows: by fixing the clamping part to the outside of the column and then adjusting the position of the support leg, the bottom of the support leg is fixed in the foundation, thereby ensuring that the column can be stably kept vertical; and the level instrument set up makes it easy for construction personnel to observe whether the surface of the clamping part is horizontal. If the clamping surface is kept horizontal, it proves that the column is in a vertical state, which can better facilitate the workers to adjust the position of the column. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments of this utility model will be briefly introduced below; obviously, the drawings described below only involve some embodiments of this utility model, and are not intended to limit this utility model.
[0017] Figure 1 A three-dimensional structural schematic diagram of the auxiliary support device is shown; Figure 2 A schematic diagram of the connection structure between the screw and the positioning unit is shown; Figure 3 A schematic diagram of the positioning unit is shown; Figure 4 A schematic diagram of the exploded structure of the positioning unit is shown; Figure 5 A top view of the connecting sleeve is shown; Figure 6 It shows Figure 5 Sectional view at point AA; Figure 7 It shows Figure 6 A magnified view of section B; Figure 8 A schematic diagram of the clamping component structure is shown. Detailed Implementation
[0018] To enable those skilled in the art to better understand this utility model, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0019] The terminology used in this invention refers to those general terms currently widely used in the art in consideration of the functionality of this invention; however, these terms may vary according to the intent, precedent, or new technology of those skilled in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of this invention. Therefore, the terminology used in this specification should not be construed as simple names, but rather based on the meaning of the terms and the overall description of this invention.
[0020] Reference Figures 1-5 This embodiment provides a highway guardrail auxiliary support device, including... Clamping component 1, which covers the outside of the column; Level 2, which is fixedly installed on the upper surface of clamping component 1; Supporting legs 3, which are multiple sets, and the multiple sets of supporting legs 3 are equidistantly distributed around the outer wall of clamping component 1.
[0021] It should be noted that the clamping component 1 can be composed of a set of semi-circular interlocking clamps, which can be fixed to the outside of the column by bolts; and the edge of the clamping component 1 is provided with a platform extending outward through sheet metal bending; the extended surface of the clamping component 1 can provide a suitable installation position for the level 2.
[0022] The level 2 consists of a transparent hollow tube and a colored liquid inside the hollow tube; the liquid does not completely fill the inside of the tube; when the air inside the tube is in the center position of the tube, it indicates that the plane where the level 2 is located is in a horizontal position; the level 2 can be used to intuitively and accurately determine whether the upper surface of the clamp 1 is horizontal.
[0023] Furthermore, the clamping member 1 is fixed to the column. When the upper surface of the clamping member 1 is kept horizontal, the column will be in a vertical state. Therefore, the verticality of the column can be determined by judging whether the upper surface of the clamping member 1 is horizontal.
[0024] The number of support legs 3 is at least three sets, and the three sets of support legs 3 are arranged in a circular array along the axis of the clamping member 1; and the support legs 3 are hinged to the clamping member 1. The cooperation of the support legs 3 can ensure that the clamping member 1 is fixed in a suitable position and prevent the column inside the clamping member 1 from tilting.
[0025] Furthermore, the positioning unit 4 includes a connecting sleeve 41 fixedly installed on the outside of the support leg 3, a set of semi-threaded sleeves 42 arranged opposite each other on the inside of the connecting sleeve 41, a button 43 for pushing the set of semi-threaded sleeves 42 closer to each other, and a pressure rod 44 for pushing the set of semi-threaded sleeves 42 away from each other; a screw 5, which is threadedly engaged with the semi-threaded sleeves 42; and a support plate 6, whose inner wall abuts against the outer wall of the column.
[0026] To further improve the stability of the column support, a positioning unit 4 is provided on the outside of the support leg 3. The semi-threaded sleeve 42 contained inside the positioning unit 4 is threadedly engaged with the screw 5. The screw 5 is threaded in, which can push the support plate 6 connected to its end to abut against the side wall of the column, thereby supporting the column from the bottom. With the help of the clamping member 1, the stability of the column can be guaranteed.
[0027] It should be noted that the end of the screw 5 is provided with a movable sleeve, and the movable sleeve is connected to the screw 5; when the screw 5 moves along a straight line along its axis, it can drive the movable sleeve to move synchronously, and the movable sleeve is hinged to the support plate 6 to ensure that the inner wall of the support plate 6 can abut against the outer wall of the column.
[0028] Specifically, to further facilitate the support plate 6 to quickly contact the outer wall of the column, the pressure rod 44 can be pressed down to push a set of semi-threaded sleeves 42 away from each other, thereby creating a larger gap between the semi-threaded sleeves 42 and the screw 5. At this time, the screw 5 can be pushed to move quickly. After the support plate 6 moves to the appropriate position, the button 43 is used to drive the set of semi-threaded sleeves 42 to move closer to each other. The semi-threaded sleeves 42 and the screw 5 form a threaded engagement. At this time, rotating the screw 5 can push the support plate 6 to move closer to the column, so that the inner wall of the support plate 6 can contact the outer wall of the column.
[0029] When installing the columns, clamp 1 is fitted onto the outside of the column, and then clamp 1 is fixedly connected to the column using bolts; then the support leg 3 is flipped so that it touches the ground and supports the column; when adjusting the angle of the support leg 3, it is necessary to ensure that the column is as vertical as possible; then the pressure rod 44 is pressed down to drive the two sets of semi-threaded sleeves 42 away from each other, and there is a large gap between the semi-threaded sleeves 42 and the screw 5, so the screw 5 can move quickly along the axis of the semi-threaded sleeves 42; the movement of the screw 5 can then drive the support plate 6 to touch the outer wall of the column; then through Button 43 drives two sets of semi-threaded sleeves 42 to move closer together, thereby forming a threaded engagement between the semi-threaded sleeves 42 and the screw 5. Then, the screw 5 can be rotated to drive the support plate 6 to contact the column, and the self-locking characteristic of the thread ensures the fixed position of the support plate 6. Multiple sets of support plates 6 cooperate with the clamping parts 1, which are located at the upper and lower positions of the column to clamp the column, further improving the stability of the column. At the same time, the construction personnel can also observe the air state inside the level 2 and adjust the distance between each set of support plates 6 and the column accordingly to ensure that the column is in a vertical state.
[0030] Reference Figures 1 to 8 As an optional embodiment, the number of connecting sleeves 41 includes a first sleeve 411 and a second sleeve 412, the first sleeve 411 and the second sleeve 412 are arranged opposite to each other and connected by bolts; the axis of the semi-threaded sleeve 42 is perpendicular to the axis of the support leg 3.
[0031] It should be noted that the first kit 411 and the second kit 412 cooperate to form a connecting sleeve 41, and the first kit 411 and the second kit 412 are fixed by bolts; the two ends of the connecting sleeve 41 cooperate to form a hollow sleeve, which is fitted inside the support leg 3; and the hollow sleeve is connected to the support leg 3 by bolts.
[0032] Specifically, the axis of the connecting sleeve 41 coincides with that of the support leg 3. When the support leg 3 rotates, the connecting sleeve 41 also rotates synchronously with the support leg 3. When the angle of rotation of the support leg 3 is large, the screw 5 set inside the connecting sleeve 41 will be far away from the column.
[0033] Furthermore, the semi-threaded sleeve 42 includes a slider 421, a baffle 422 fixedly connected to the slider 421, and a guide post 423 coaxially arranged with the support leg 3; the first kit 411 and the second kit 412 cooperate to form a limiting groove that is compatible with the slider 421; a set of semi-threaded sleeves 42 can move along the axis of the support leg 3.
[0034] It should be noted that the slider 421 and the connecting sleeve 41 are connected by welding. When a set of semi-threaded sleeves 42 are fitted together, the slider 421 forms a rectangular structure. The slider 421 can slide along the limiting groove of the connecting sleeve 41. The limiting groove can limit the slider 421 and also restrict the installation position of the semi-threaded sleeve 42, making it easier for workers to assemble the semi-threaded sleeve 42 and the connecting sleeve 41.
[0035] Specifically, the guide post 423 and the semi-threaded sleeve 42 are connected by welding. The axis of the guide post 423 coincides with the axis of the support leg 3, and the guide post 423 passes through the connecting sleeve 41 and extends to its outer side. A through hole is opened inside the connecting sleeve 41, and the guide post 423 slides along the inside of the through hole. The movement trajectory of the semi-threaded sleeve 42 can be restricted by the cooperation between the guide post 423 and the through hole, so that the semi-threaded sleeve 42 can only move in a straight line along the long axis of the support leg 3.
[0036] Furthermore, a positioning sleeve 45 is fitted on the outside of the button 43, and the positioning sleeve 45 is fixedly connected to the connecting sleeve 41; the button 43 includes a guide plate 431 and a spring 432 disposed inside the button 43; one end of the spring 432 is connected to the button 43, and the other end abuts against the outer wall of the connecting sleeve 41.
[0037] It should be noted that the positioning sleeve 45 is coaxially arranged with the button 43, and the positioning sleeve 45 is fixedly connected with the connecting sleeve 41. The positioning sleeve 45 has a limit hole inside that cooperates with the limit block on the outer wall of the button 43, thereby effectively preventing the button 43 from completely separating from the positioning sleeve 45.
[0038] A guide plate 431 is fixedly connected to the end of the button 43, and a spring 432 is provided inside the button 43. One end of the spring 432 is fixedly connected to the button 43, and the other end abuts against the side wall of the connecting sleeve 41. By releasing the elastic potential energy through the spring 432, the button 43 can be pushed to move away from the positioning sleeve 45.
[0039] Furthermore, a first pressing block 4221 is provided on one side of the baffle 422, and the first pressing block 4221 is fixedly connected to the baffle 422; a second pressing block 4311 is provided on the inner side of the guide plate 431, and the second pressing block 4311 is fixedly connected to the guide plate 431; the second pressing block 4311 abuts against the first pressing block 4221, which can push a set of semi-threaded sleeves 42 to abut against each other.
[0040] It should be noted that the first pressure block 4221 is located on the side of the slider 421 near the guide post 423, and the first pressure block 4221 is fixedly connected to the baffle 422 by screws; after a set of semi-threaded sleeves 42 are engaged, there is a certain gap between the set of baffles 422.
[0041] Specifically, the second pressure block 4311 is located on the side near the center of the guide plate 431 and the button 43, and the second pressure block 4311 is fixedly connected to the guide plate 431. When the second pressure block 4311 abuts against the first pressure block 4221, the second pressure block 4311 will squeeze a set of semi-threaded sleeves 42 closer to each other, thereby making the set of semi-threaded sleeves 42 fit together. After the semi-threaded sleeves 42 are engaged, they can be threadedly connected to the screw 5, thereby driving the screw 5 to rotate and causing the support plate 6 to abut against the outer wall of the column.
[0042] Furthermore, the pressure rod 44 is fixedly connected to the button 43, and the pressure rod 44 moves synchronously with the button 43; the pressure rod 44 includes a pressing part 441 disposed at its end; the second pressure block 4311 is offset from the first pressure block 4221, and the bottom of the pressure rod 44 abuts against the top of the baffle 422.
[0043] It should be noted that the pressure rod 44 is fixedly connected to the button 43. Under normal conditions, the spring 432 releases elastic potential energy, which can push the second pressure block 4311 to abut the first pressure block 4221. The two sets of second pressure blocks 4311 can drive a set of semi-threaded sleeves 42 to approach each other, so that the set of semi-threaded sleeves 42 can form a threaded sleeve with a circular cross-section.
[0044] By pressing down button 43, the second pressure block 4311 moves synchronously away from the pressure rod 44. During the movement, the second pressure block 4311 is offset from the first pressure block 4221. Then, the pressure rod 44 is pushed down further. The surface of the pressing part 441 abuts against a set of baffles 422. As button 43 is pressed down further, a set of semi-threaded sleeves 42 can be pushed away from each other. This disengages the semi-threaded sleeves 42 from the screw rod 5. At this time, the screw rod 5 can be quickly pushed closer to or away from the column, making it easier for construction personnel to adjust the position of the support plate 6.
[0045] Furthermore, the bottom of the support leg 3 is connected to a ground nail via a universal joint; the ground nail connection at the bottom of the support leg 3 makes it easier for workers to insert the ground nail into the foundation to maintain the stability of the column structure.
[0046] Specifically, the 3rd anchor point is connected to the ground stake via a universal joint, which better ensures that the stake can be inserted into the ground at the appropriate angle and fixed in place.
[0047] Furthermore, the clamping member 1 includes a first clamp 11 and a second clamp 12, which are hinged together.
[0048] It should be noted that there are two sets of second clamps 12, with the two sets of second clamps 12 located at both ends of the first clamp 11, and the second clamps 12 and the first clamp 11 are hinged together by hinges.
[0049] Specifically, the first clamp 11 and the two sets of second clamps 12 can be fitted together to cover the outside of the column, thereby ensuring that the clamping member 1 is fixed to the column.
[0050] It should be noted that the length of the support leg 3 is adjustable, and after the support leg 3 is stretched to a suitable length, the length of the support leg 3 can be fixed by a fixing device so that the support leg 3 can fix the column on uneven ground and keep the column in a vertical state.
[0051] When construction workers need to ensure the column is vertical, they press the first clamp 11 tightly against the side wall of the column, then flip the two sets of second clamps 12 so that they are also pressed tightly against the side wall of the column. The ends of the two second clamps 12 are then connected with bolts to ensure the position of the clamp 1 and the column is fixed. The column is then placed in a suitable position to ensure it is vertical. The support legs 3 are then flipped according to the column's position, and the lengths of each set of support legs 3 are adjusted accordingly. Ground nails are then inserted into the ground to maintain the stability of the entire support structure. After fixing, the level of the upper surface of the clamp 1 can be observed using a level 2 mounted on its upper surface. If the upper surface of the clamp 1 tilts, the tilt of the column can be adjusted by changing the direction of the support plate 6 against the column. To facilitate quick adjustment of the support plate 6... When the support plate 6 contacts the side wall of the column, the button 43 can be pressed down, causing the pressure rod 44 to push a set of semi-threaded sleeves 42 away from each other, so as to ensure that there is sufficient gap between the semi-threaded sleeves 42 and the screw 5. Then, the screw 5 is pushed to drive the support plate 6 to quickly contact the side wall of the column. After the support plate 6 contacts the column, the button 43 can be released, the spring 432 releases its elastic potential energy, and the button 43 can be pushed back to its original position, so as to ensure that the second pressure block 4311 and the first pressure block 4221 are aligned. The second pressure block 4311 pushes a set of semi-threaded sleeves 42 closer to each other, so that the semi-threaded sleeves 42 cooperate with the screw 5. At this time, rotating the screw 5 can drive the support plate 6 to further compress the side wall of the column. If the upper surface of the clamping part 1 is not flat, the bottom of the column can also be moved by the support plate 6, so that the column is in a vertical state.
[0052] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of this utility model.
[0053] Importantly, the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A highway guard rail auxiliary support device, characterized by: include, Clamping member (1), the clamping member (1) covers the outside of the column; A level (2) is fixedly installed on the upper surface of the clamping member (1); Support legs (3), the number of support legs (3) is multiple sets, and the multiple sets of support legs (3) are equidistantly distributed around the outer wall of the clamping member (1); The positioning unit (4) includes a connecting sleeve (41) fixedly installed on the outside of the support leg (3), a set of semi-threaded sleeves (42) arranged opposite to each other on the inside of the connecting sleeve (41), a button (43) for pushing the set of semi-threaded sleeves (42) closer to each other, and a pressure rod (44) for pushing the set of semi-threaded sleeves (42) further away from each other. The screw (5) is threadedly engaged with the semi-threaded sleeve (42); The inner wall of the support plate (6) abuts against the outer wall of the column.
2. The auxiliary support device for highway guardrails according to claim 1, characterized in that: The number of connecting sleeves (41) includes a first sleeve (411) and a second sleeve (412), the first sleeve (411) and the second sleeve (412) being arranged opposite to each other and connected by bolts; The axis of the semi-threaded sleeve (42) is perpendicular to the axis of the support leg (3).
3. The auxiliary support device for highway guardrails according to claim 2, characterized in that: The semi-threaded sleeve (42) includes a slider (421), a baffle (422) fixedly connected to the slider (421), and a guide post (423) coaxially arranged with the support leg (3). The first kit (411) and the second kit (412) cooperate to form a limiting groove that is compatible with the slider (421); A set of the semi-threaded sleeves (42) can be aligned along the axis of the support leg (3).
4. The auxiliary support device for highway guardrails according to claim 3, characterized in that: The button (43) is fitted with a positioning sleeve (45) on its outer side, and the positioning sleeve (45) is fixedly connected to the connecting sleeve (41); The button (43) includes a guide plate (431) and a spring (432) disposed inside the button (43). One end of the spring (432) is connected to the button (43), and the other end abuts against the outer wall of the connecting sleeve (41).
5. The auxiliary support device for highway guardrails according to claim 4, characterized in that: A first pressing block (4221) is provided on one side of the baffle (422), and the first pressing block (4221) is fixedly connected to the baffle (422); A second pressure block (4311) is provided on the inner side of the guide plate (431), and the second pressure block (4311) is fixedly connected to the guide plate (431); The second pressure block (4311) abuts against the first pressure block (4221) and can push a set of the semi-threaded sleeves (42) to abut against each other.
6. The auxiliary support device for highway guardrails according to claim 5, characterized in that: The pressure rod (44) is fixedly connected to the button (43), and the pressure rod (44) moves synchronously with the button (43); The pressure bar (44) includes a pressing part (441) disposed at its end. The second pressure block (4311) is offset from the first pressure block (4221), and the bottom of the pressure rod (44) abuts against the top of the baffle (422).
7. The auxiliary support device for highway guardrails according to claim 6, characterized in that: The extrusion section (441) abuts against the side wall of the baffle (422), and the downward movement of the pressure rod (44) can push a set of semi-threaded sleeves (42) away from each other; The screw (5) is disengaged from the semi-threaded sleeve (42), and the screw (5) can be fed in quickly.
8. The auxiliary support device for highway guardrails according to claim 7, characterized in that: The bottom of the support leg (3) is connected to a ground nail via a universal joint.
9. The auxiliary support device for highway guardrails according to claim 8, characterized in that: The clamping member (1) includes a first clamp (11) and a second clamp (12), which are hinged together.
10. The auxiliary support device for highway guardrails according to any one of claims 1 to 9, characterized in that: The length of the support leg (3) can be adjusted by telescoping.
