JGC - Calculation program for Gas springs

With this program, we would like to help you select an appropriate gas spring for your application.

The wizard/assistant has been developed to help users who are not familiar with gas springs in 8 easy steps to get the best possible results. The JGC yields basic instructions for every step of the calculation and there is also a help function with more detailed information for your assistance.

Users, which are familiar with the program, also have the possibility to switch directly to the full-mode.

To prevent misuse of the calculation program, details of the calculated gas spring extension force are not included in the internet version.

Only the manual force or the force that must be applied from the user at the point of manual force (grip) is shown. The drag and drop feature in the full mode allows an easy adjustment of the gas spring fixing points on the flap and frame. By clicking on them with the left mouse button and moving them to the desired position, the manual force diagram will be adjusted accordingly.

After you have completed the calculation, we ask you to e-mail or fax us your results. Shortly after we receive your inquiry, we will review your calculation, optimise it if needed and forward you a quotation.

In the theoretical stroke/extended length panel, the required stroke/extended length will constantly be updated depending on the selected flap/frame fixing points. Please note the following approximate values:

	Gas spring:	2 x stroke + 100mm
	Traction spring:	1 x stroke + 133mm

Specific information for length calculation can be found in our catalog or homepage.

Should you need help with a calculation, you can switch to the wizard mode by clicking on "File" and "New". Further information can be found under "Help" and "instructions".

If you should have any further questions, you can also contact us directly under:

JGCinfo@bansbach.de

	Tel:	+49 (0) 7172 - 9107 0
	Fax:	+49 (0) 7172 - 9107 44

Important: Calculations are normally based on various assumptions. We exclude any liability or guarantee for calculations.

Assistent/Wizard

Links zu Wizard Schritts:

Basics: Step 1/8
Handel position: Step 2/8
Center of Gravity and Weight: Step 3/8
Center of gravity end angle: Step 4/8
Mounting points on the flap: Step 5/8
Mounting points on frame: Step 6/8
Entered data check: Step 7/8
Animation: Step 8/8

Basics: Step 1/8

The data is entered in a coordinate system(X and Y axis). It is to be entered in millimeters and measured from the middle of the hinge or pivot, which is 0 in both axes. The position of the hinge/pivot is always X=0 / Y=0.

Important: When entering data, always note that the values are to be entered at the starting (closed) position of the application and the movement is always counter clockwise.

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Handel position: Step 2/8

In this step, the position of the handle is defined (HAP). This is the point at which the user will push or pull the flap/application manually.

For simplicity, in most cases the total length of the flap should be entered. If you require a more exact calculation, the distance from centre pivot/ hinge to the centre of the grip should be entered.

In case of a bended or angled flap, the exact position of the grip can be entered in X/Y coordinates (only available in full-mode). For this option, click on the menu "Options" and "Coordinates" and select "Decart. coord"

In the full-mode, we speak of negative and positive manual-force, which is nothing other than:

Positive manual -force: Amount of manual force in Newtons, which must be applied in the counter clockwise direction to open the flap.
Negative manual-force: Amount of manual force in Newtons which must be applied in the clockwise direction to closed the flap.

See below graphic for an explanation of the manual hand force diagram (red line).

In this example, the user needs 10N manual force to lift the flap from the starting position or 0° when pulling at the previously defined grip (HAP). When the flap reaches approx. 22° the gas spring is strong enough to lift it and hold it without any other external force.

To close the flap, the user must pull the flap from the open position (60°) with 10N manual force until approx. 22°. At this point the weight of the flap is greater than the extension force of the gas spring and the flap will close without any manual force.

The friction of the hinges and gas spring are not included in the calculation.

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Center of Gravity and Weight: Step 3/8

In this step, you will define the center of gravity (CoG) and effective weight. The effective weight must be entered in Newton (N). 1 Kilogram is approx. 10N (9.86N) or 1 kp.

When defining the center of gravity, it is necessary to enter the coordinates from the start position. In the below example the center of gravity is moved from the vertical position past the horizontal position for a total of 130°. The coordinates of the centre of gravity for the below example are X = 0 / Y = -500.

If the position of the center of gravity is unknown, a general rule of thumb is half of the length of the flap. Example: Flap length 1000mm, estimated center of gravity: 500mm.

The exact coordinates of the center of gravity can be defined in the full-mode. For this option, click on the menu "Options" and "Coordinates" and select "Decart coord".

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Center of gravity end angle: Step 4/8

The starting point of the swivel movement is the start position of the application.

From the closed position, the flap will swivel to the entered center of gravity end angle value in degrees. The below example of a floor cover swings from 0° or horizontal to approx. 70°. The entered value is 70°, which is also the end position.

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Mounting points on the flap: Step 5/8

The mounting points on the flap are always entered with the flap in the closed position. The below example flap length is 1000mm.

If for example the swivel movement is from 0° to 70°, the X-value on the flap should be approx. 60% - 80% of the entire flap length. The Y-value is normally just under the flap depending on the thickness of the flap or the fitting on which the gas spring is to be mounted on. Y = -70mm for example.

If the swivel movement is from -90° to 0°, the negative Y-value is normally approx. 15 - 30% of the entire flap length. Depending on the flap thickness, the X-value is fixed at -70mm for example.

Please note: Especially for unstable or heavy flaps, the above standard values may vary from the above.

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Mounting points on frame: Step 6/8

The starting point for selection of the mounting points on the frame is again when the flap is in the closed position.

If the swivel movement is from 0° to 70° as in the above example, the X-value of the mounting point on the frame should be approx. 20 - 30% of the total flap length. The Y-value should be approx. 100mm below the mounting point on the flap as in the above example.

If the swivel movement is from -90° to 0°, the negative Y-value of the mounting point on the frame should be about 70 - 80% of the entire flap length. The X-value may vary depending on the thickness of the flap and the manual hand force. Example -30mm.

Please note: Especially for unstable or heavy flaps, the above standard values may vary from the above.

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Entered data check: Step 7/8

Step 7 gives you the opportunity to recheck the entered data.

Check if the entered data is correct.

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Animation: Step 8/8

The last step gives you the opportunity to check the movement of flap according to the entered data.

By clicking the animation bar, the program will animate the movement of the application until opened. The program also shows you the required stroke during the swivel motion.

Unfortunately, due to technical reasons, we cannot manufacture all calculated strokes and extended lengths. The minimal extended length is always based on the stroke length.

Please see the following for approx. length calculation guides:

	Gas spring:	2 x Stroke + 100mm= Extended length
	Gas traction spring:	Stoke + 133mm=inserted length (piston rod retracted)

Detailed information on length calculation can be found in our latest catalogue or our Homepage.

Important: Calculations are normally based on various assumptions. Please note: we exclude any liability or guarantee for calculations.

Parameter - Further data:

There is a possibility to alter the following parameters in the full-mode, which cannot be changed in the wizard mode. Please note that they must only be changed on rare occasions.

Friction:
The calculated extension force and the displayed manual hand force are not influenced when the value is changed.

The default friction value is 40N but if the calculated force is over 1000N it can be changed to e.g. 100N.

Click on "View" and then "Friction" to review the increased required manual hand force.

Temperature:
The general setting is 20°C. The hand force displays the required manual hand force at 20°C or the entered value.

Depending on the settings for the max./min. temperature, the manual hand force curve will show the required manual hand force for these temperatures also. Click on the Menu "View" and then temperature to have these displayed.

Progressivity:
When gas springs are compressed, the pressure in the spring rises which in turn increases the extension force. The difference in force from the extended position or nominal force to the compressed position is the progressivity. It varies depending on piston rod and cylinder diameter. These values can be found in the below table and further values can be found on the Bansbach homepage or our latest catalogue.

Please note: progressivity values are calculated for standard stroke/extended length calculations.

Example: If the calculated stroke for a Ø10/22 series spring is 120mm, the extended length including hinge eyes should be 330mm. The progressivity is approx. 39% as listed below.

The nominal force for traction springs is measured when the piston rod is in the pulled in position. Progressivity takes place when the piston rod is extended.

Spring series selection depends on the calculated force. The default progressivity is 40%, which should be corrected after or during calculation. Please use standard gas spring values.

Series	6/15	8/19	10/22	14/28	10/40	20/40
Progressivity %	27	33	39	52	8	45

Please note: Gas springs with strong end damping may have a much higher progressivity percentage than normal and springs with a longer than usual cylinder length may have a much lower progressivity than normal.

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