Type F: with rubber stop, locking device in back, detach function
No. 1: Fastening using through-holes
Steel, zinc plated, blue passivated ZB
Roller bearing steel, hardened
Ball cage, outer slide
Ball cage, inner slide
Steel, zinc plated
Rubber stop and detach function
Plastic / Elastomer
Operating temperature -20 °C to 100 °C
Telescopic slides GN 1408 are installed vertically and in pairs. The stroke reaches ≈ 100 % of the nominal length l1 (full extension).
The telescopic slides are delivered in pairs. They can be installed on the extension on either the left or right side due to the mechanics. All mounting holes are easy to reach through auxiliary holes. Only the mounting holes are shown, but other production-related holes may be present.
For the said loading forces FS to be absorbed reliably in the surrounding structure, all available through-holes of the outer slide having a diameter (Ø) of 4.2 and of the inner slide having a diameter (Ø) of 4.4 must be used. The elongated holes, Ø 4.2 x 4.4 of the outer slide and Ø 4.4 x 4.6 of the inner slide, are used likewise for fastening and facilitate adjustment during mounting when needed. Failure to use fastening screws reduces the specified load capacity accordingly. The following screws can be used for mounting:
|Designation - standard||Outer slide||Inner slide|
|Hexagon socket button head screw ISO 7380||M 4||M 4|
|Pan head screw, Phillips ISO 7045||M 4||M 4|
|Pan head tapping screw, Phillips ISO 7049||ST 3.9 / 4.2||ST 3.9 / 4.2|
The rubber stops of type F dampen the impact of the slide in the respective end position. This feature minimizes noise development and increases the lifespan. Attached to the slides in a partially concealed, partially visible manner, the stops meet each of the requirements in regard to shape, material, and hardness.
In the back stop position, the rubber stop takes on additionally a locking function, which is noticeable through a slight resistance on opening and closing.
If larger static or dynamic loads occur in the direction of extension, they should be absorbed by external stop elements.
Type F has additionally a detach function through which the extension slides can be completely separated from one another in the area of the middle and inner slide. This feature not only facilitates mounting. It also allows the extension to be quickly removed, for example, when frequent maintenance work is performed on the components located behind.
The telescopic slide can be quickly and easily detached in the extracted position through activation of the release lever, allowing the inner slide to be removed from the front.
For reattaching the slides, the ball cages need to be moved to the front end position. Then the inner slide is inserted to the back end stop where it locks into place automatically.
The protected arrangement of the release mechanism prevents accidental detachment of the slide.
Telescopic slides offer smooth running, wear-free, and quiet linear motion. They are used in a very wide range of applications. The spectrum ranges from the most simple extensions and drawers to high-quality variants that are used in the industrial environment on machines, production systems, and equipment. The telescopic slides have a multitude of positive features and are still very interesting from an economic standpoint. Here are a few examples of use: sliding doors, protective hoods, keyboards and PC pullouts, vehicle equipment, storage shelves, battery boxes etc.
Telescopic slides can come with a number of component options. Some are available for one of the two stop positions and in combination, and they are defined by the type in the article number.
Telescopic slides consist of an outer and inner slide as well as additionally of one or two middle slides depending on design and/or required extension lengths. The slides are interconnected through appropriately shaped geometry and move by means of ball bearings. A ball cage keeps the bearings spaced and in position.
The slides are usually mounted through countersunk holes or through-holes. Other options, such as threaded bolts or support brackets, are available as an alternative.
In regard to the length of the extension, telescopic slides can be divided into three categories: partial extension, full extension, and over extension. The categories are defined by the achievable stroke l2, which is listed in relation to the nominal length l1.
|Type of extension||Extension diagram|
|Partial extension: l1 = 100 % -> l2 = min. 75 %|
|Full extension: l1 = 100 % -> l2 = min. 100 %|
|Over extension: l1 = 100 % -> l2 = min. 150 %|
All slides have internally constructed stops in the front and back end position. The stops prevent the slides from extending unintentionally. Depending on the available installation space and required stability, the stops are designed accordingly in a metallic form or with additional plastic or elastomer parts as a rubber stop to prevent the slides from hitting the end positions with too much force.
Also the telescopic slides can come with a variety of accessory functions. Examples include locking devices, latches, detach functions, and self-retracting mechanisms, some of which are dampened. Some additional functions are available, depending on slide variant, for the back or front stop position and in combination. Furthermore, customer-specific modifications regarding the fastening of the slides can be made.
|Standard||Type of extension||Load capacity||Basic length||Material||Fastening||-||-|
|Partial extension T||per pair at 10,000 cycles||retracted position||Steel ST||Through-holes||Countersunk holes||Outer slide, through-holes/ Inner slide, countersunk holes|
|Full extension |b bb|||in N||in mm||St. Steel NI||(Id. no. 1)||(Id. no. 2)||(Id. no. 3)|
|GN 1400||T||280||300 - 500||ST||X||-||-|
|GN 1404||T||780||300 - 700||ST||-||-||X|
|GN 1408||V||250||250 - 700||ST||X||-||-|
|GN 1410||V||510||250 - 800||ST||X||-||-|
|GN 1412||V||430||300 - 700||ST||X||-||-|
|GN 1414||V||360||300 - 650||ST||X||-||-|
|GN 1418||V||430||350 - 650||ST||X||-||-|
|GN 1420||V||1290||300 - 1200||ST||-||X||-|
|GN 1422||V||1290||300 - 800||ST||-||X||-|
|GN 1424||V||750||350 - 700||ST||-||X||-|
|GN 1426||V||1380||500 - 800||ST||-||X||-|
|GN 1430||V||2120||400 - 1200||ST||-||X||-|
|GN 1432||V||2300||400 - 800||ST||-||X||-|
|GN 1440 | Type B||V||3250||300 - 1500||ST||X||-||-|
|GN 1440 | Type M||V||3250||300 - 1500||ST||X||-||-|
|GN 1440 | Type K||V||3250||300 - 1500||ST||X||-||-|
|GN 1440 | Type Q||V||3250||300 - 1500||ST||X||-||-|
|GN 1450||V||510||300 - 600||NI||X||-||-|
|GN 1460||V||1050||250 - 800||NI||-||X||-|
|without rubber stop||with rubber stop, back-front||Locking device back||Locking device back, detach function||Latch back||Latch front||Latch back-front||Self-retracting mechanism, dampened / not dampened||Push to open - mechanism||Extension on both sides|
|Type |bbb|||Type F||Type M||Type K||Type Q|
|GN 1440 | Type B||-||X||-||-||-||-||-||-||-||-|
|GN 1440 | Type M||-||X||-||-||X||-||-||-||-||-|
|GN 1440 | Type K||-||X||-||-||-||X||-||-||-||-|
|GN 1440 | Type Q||-||X||-||-||-||-||X||-||-||-|
Follow the installation information below when mounting telescopic slides. Ideally this information should have already been taking into account in the design of the extensions. Doing so ensures smooth running, quiet, and low-wear operation of the slides over a long period of time and guarantees function in the long run.
In general use all holes intended for fastening when mounting telescopic slides. Doing so will ensure that the forces resulting from the maximum load capacity FS (nominal load) can be transferred safely from the telescopic slides from and to the surrounding structure. Failure to use fastening screws reduces the specified load capacity accordingly.
The outer and inner slides have other openings and auxiliary holes in addition to the holes intended for mounting. The catalog drawings and the CAD data available for download do not show these holes to exclude confusion and design faults. These holes are needed, among other things, for the fastening of type-dependent component features, such as the self-retracting mechanisms.
Some slide variants have fastening options for screws of various sizes. In this case, all positions of a size or type should be used. Auxiliary holes, which ensure that all mounting holes can be reached, are found accordingly in the CAD data, but are not pictured in the catalog drawings.
The type and specification of suitable screws can be found on the respective catalog pages. It is generally recommended to use screws of tensile strength class 8.8 under consideration of the specified tightening torque.
Telescopic slides are preferably installed arranged vertically and in pairs in a horizontal position. This ensures that the highest possible stability and torsional stiffness is reached in the smallest installation spaces and allows for absorption of the maximum load (nominal load). The performance features are optimum in this installation position, and wear is reduced to a minimum.
The horizontal or lying installation of the slide is likewise possible with certain restrictions. The maximum load in this case is only about 20 % to 25 % of the specified nominal load. The less favorable slide profile results, therefore, in considerably higher bending in the extended state. As a result, the ball cages may leave streaks on the heads of the fastening screws. In case of doubt, check the function under load in a test set-up.
Installing slides in a perpendicular position to the direction of extraction is not recommended because increased cage slip occurs in this case. This means that the upper and lower end position of the slide can be reached in some circumstances only with an increased amount of force after a few cycles since the force of gravity causes the ball cage to become dislocated from its correct position.
The following examples show possible installation positions of telescopic slides that are considered favorable or acceptable and some that are regarded as unfavorable and should, therefore, be avoided.
|favorable||vertically, both sides, favorable|
|acceptable||vertically shifted, on both sides, acceptable||vertically inclined, on both sides, acceptable|
|unfavorable||vertically, on one side, unfavorable||horizontally, on both sides, unfavorable|
The maximum load capacity of telescopic slides depends on the slide profile, the nominal length l1, and the resulting stroke l2. Furthermore, the extension width, the slide materials used, and the parts of the component options, such as the dampened self-retracting mechanism, have a considerable influence.
The information on the maximum load capacity of the telescopic slides was determined in fatigue tests under the following
Wear, performance, and maximum bending were assessed after every test segment.
Telescopic slides demonstrate elastic bending under load in the extended state. The bending is most noticeable at the far end of the inner slide. The general rule is that the extent of deformation may not be higher than 4.25 % of the stroke path. All slides are within this value on maximum load.
A telescopic slide having a nominal length of l1 = 500 mm is moved to the end position and stressed with the maximum load throughout the extension finish. The bending at the front-most point of the slide may now be a maximum of 21.25 mm.
All components of the telescopic slides are subject to manufacturing tolerances that ensure consistent quality and a long lifespan.
Since the stroke results from the interaction of all individual parts of the telescopic slides, the sum of all individual tolerances also has to be taken into account for the length tolerance of the stroke. In addition, slight deformation of any existing rubber stops should be mentioned. This results overall in proportionately large total tolerances that are listed on the respective catalog pages and can, therefore, be taken into account in the design layout of extensions.
The permissible extraction and retraction speeds of the telescopic slides are set at a maximum speed of 0.3 m/s. Shortly before the end of stroke, the speed should be reduced to less than 0.15 m/s so that the stops, rubber stops, dampened self-retracting mechanisms etc., do not have an excessive amount of impact stress.
The telescopic slides made by Elesa+Ganter are manufactured out of high-quality steel or stainless steel bands.
The stainless steel telescopic slides are generally delivered with mill-finish surfaces.
The steel telescopic slides are partly made out of a pre-zinc plated steel band and are subsequently batch zinc plated and blue passivated with 5 to 7 μm. Corrosion resistance in the salt spray test for at least 72 hours against white rust is ensured in this way.
To achieve higher corrosion resistance, finish refinements can be provided on request. Two processes are available:
All materials and finish refinements used are RoHS compliant.
Telescopic slides are permanently lubricated with high-quality, mineral-oil-based and lead-free bearing lubricants.
For stainless steel telescopic slides, special FDA-compliant lubricants are used that are tasteless and odorless. The lubricants comply with lubricant class H1, which allows them to be used in areas where it is technically infeasible to prevent occasional contact with food. Generally direct contact can be prevented by taking appropriate actions, such as optimum placement of slides or the use of covers.
Re-lubrication is generally not necessary under normal conditions of use since the ball cages and bearings “push out” small amounts of obtained dirt from the slides when the slides move. In applications where there is heavy contamination, the slides should be cleaned from time to time with a clean cloth and then re-lubricated. Acceptable lubricants for the steel variants are, for example, Shell Alvania EP 1 and Klüberplex BE 31-222.
In the event of quick changes of direction and high acceleration forces, cage slip can occur in the worst case, especially with long ball cages. In these cases, the cage does not move synchronously at half the speed of the middle and inner slides. Instead it loses its correct position gradually due to sliding. In such cases an “idle stroke” may need to be moved in the front and back stop position of the slide, at a moderate speed and under slight load to reposition the cage.
The temperature of use of telescopic slides is within the range of -20 °C to 100 °C and is determined primarily by the plastic and elastomer parts used in the slides. Depending on place of use and application, the user may have to check the function of the extensions if the temperature is at the limit.
Telescopic slides can be delivered with a number of component options. Some are available for one of the two stop positions and in combination, and they are defined by the „type“ in the article number.
The following overview shows examples of possible characteristics of the various types and component features. The components used and the employed mechanisms are adapted to match the available installation space, cross section, and structure of the selected slides and have accordingly different designs depending on slide variant. Functionality is comparable, however, and sometimes even identical.
The rubber stops used in almost all slide variants dampen the impact of the slide in the respective end position. This feature minimizes noise development and increases the lifespan. Attached to the slides in a partially concealed, partially visible manner, the stops meet each of the requirements in regard to shape, material, and hardness.
If larger static or dynamic loads occur in the direction of extension, they should be absorbed by external stop elements.
The locking function is noticeable by a slight resistance of the slides in the end positions, which has to be overcome on opening and closing. The locking device in the back stop position is usually integrated into the rubber stop function, making additional components unnecessary.
The locking device is frictionally engaged and, therefore, does not act as a positive locking latch.
Unlike locking devices, a latch secures the slides in the stop positions in a frictionally engaged way. Telescopic slides with latches are used when the slides need to be protected against independent extension or retraction, for example, due to a tilted position.
A mechanism found within the inner slide latches automatically spring-loaded by moving over a ramp on reaching the respective stop position. Pressing the release lever releases the latch, allowing the slide to move again.
If larger loads occur in the direction of extension in the latched position, they should be absorbed by external latch elements.
Telescopic slides can have an integrated self-retracting mechanism, which improves considerably the ease of use when closing the extensions.
In the version shown in the example, the slides are retracted and held in the back end position automatically by means of a retraction mechanism on the last 22 mm of stroke with a force of approximately 30 newtons for each slide pair. This force has to be overcome accordingly on opening the extension.
This variant is also designed in such a way that mechanism uncouples and will not be damaged when the extension is opened or closed in a jerky manner or too quickly. On the following stroke, the self-retracting mechanism clicks back into place automatically, ensuring that the function remains intact.
Dampened self-retracting mechanisms are also called “soft-close” and are divided into two main functions. They offer the best possible ease of use on closing the extension.
In the example shown, the self-retracting mechanism takes over the automatic retraction of the slides on the last 40 mm of stroke in the back stop position, where the slides are then held in place. The retraction force is about 35 newtons per slide pair. Also the dampening mechanism slows down to a considerably reduced speed the closing movement on the said stroke, while achieving a extremely gentle and smooth closing movement. This retraction force has to be overcome accordingly on opening the extension.
When dampened self-retracting mechanisms are used, the specified load values and stroke speeds may not be exceeded on reaching the retraction mechanism.
Telescopic slides with a detach function can be completely separated from one another in the area of the middle and inner slide. This feature not only facilitates mounting. It also allows the extension to be quickly removed, for example, when maintenance work is performed on the components located behind.
In the example shown, the telescopic slide can be quickly and easily detached in the extracted position through activation of a flat spring, allowing the inner slide to be removed from the front.
For reattaching the slides, the ball cages need to be moved basically to the front end position. Then the inner slide is inserted to the back end stop where it locks back into place automatically.
The protected arrangement of the various release mechanisms prevents accidental detachment of the slide.
Support brackets on the inner slide are available on request for some slide variants, even in small quantities. The support bracket is used for simple fastening, for example, of a drawer, if side mounting is not possible. Fastening occurs by means of through-holes that are arranged at a right angle in the bracket.
The fastening screws secure only the position of the drawer in this case. Additional reinforcement of the slides themselves, as with side mounting, is not possible. The drawers should therefore be designed as rigidly as possible so that the perpendicular load does not introduce any unnecessary tension through the support bracket into the slides.
Telescopic slides can be fitted with a “push to open” or “touch to open” mechanism. In addition to ease of opening, the system allows you to have drawers without a front handle. This makes it easy to achieve a sleek, high-end appearance.
The system is typically actuated by pressing your hand on the front of the slide-out shelf or drawer. In the example shown here, the required force to activate the opening mechanism is about 40 N per rail pair. The inner rail extends 5 mm in its home position and can be pressed in by about 8 mm in the closing direction. This should be taken into account in the design in order to prevent collisions. The pressure or release point is reached at about 3 mm, which causes the drawer to slide out smoothly to about 40 mm in the opening direction after being released.
When using telescopic slides with “push to open” actuation, the load values and travel speeds upon reaching the retraction mechanism as specified in the respective standard sheet may not be exceeded.
In addition to the standard fastening of telescopic slides, with through-holes or countersunk holes, other fastening variants can be provided on request. Possible fastening types can be implemented on the inner or outer slide and in combination depending on the requirement. Some examples are shown below. Other, customer-specific special fastenings are also possible after feasibility has been checked.
|Countersunk holes||Other fastening holes||Press nuts|
|Threaded studs / bolts||Mounting studs / bolts||Fastening clips|
|Mounting plates, spot-welded||Spacers, spot-welded||Support brackets, spot-welded|
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