EP3559500A1

EP3559500A1 - Gas spring with a lock

Info

Publication number: EP3559500A1
Application number: EP17884087.2A
Authority: EP
Inventors: Arunvel Thangamani; Srikanth GANNE; Robin C JAYARAM
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS
Priority date: 2016-12-21
Filing date: 2017-12-06
Publication date: 2019-10-30
Also published as: BR112019009667A2; EP3559500A4; WO2018116317A1; CN110023645A

Abstract

A locking device [100] including a gas spring and locking element is disclosed. The gas spring further includes a gas compressed cylinder [102] and a piston rod [104]. A locking element is attached on the piston rod [104] of the gas spring. The locking element includes a key hole [108], a locking lever [110], an enclosure unit [122] and a pin [112]. The key hole [108] and the locking lever [110] is attached in the enclosure unit [122]. The pin [112] is attached to the cylinder [102] of the gas spring. The key hole [108] enables the rotation of the locking lever [110]. This rotation enables the engagement and disengagement of the locking lever [110] with the pin [112], which therein results in locking and unlocking the locking device [100].

Description

GAS SPRING WITH A LOCK

Technical Field

[0001] The present disclosure relates generally to a gas spring with a locking device, and in particularly, to a locking device for an automobile tailgate.

Background

[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Tailgate is a door or an opening of a vehicle that may be hinged at the top, side, or bottom. Gas springs are particularly used in motor vehicles as lifting aids for tailgates. The gas spring typically includes a cylinder which preferably contains a gas charged under pressure.

[0004] Earlier all the cars in the market were not fully glazed and had a metal frame to support the glass all along the edges as shown in FIG. 1. The trending line of automotive glazing design has brought in the idea of a complete glass tailgate or fully glazed tailgate, as shown in FIG. 2. A fully glazed tailgate is provided to cater three functional mechanisms such as locking, opening/holding and hinging. Typically, three separate components are required to perform these three functional mechanisms. The existing fully glazed tailgates has four or more holes on the it to fix the components that enable the above mentioned functional mechanisms. Preferably, two holes for hinging, one hole for locking and one hole for lifting is required. Such holes drilled on to the fully glazed tailgate reduces the reliability and durability of the glazing and further increases the processing cost and time. Drilling more number of holes weakens the glazing and makes it more prone to shattering.

[0005] Further, the locking component for locking the tailgate is located away from the opening/holding component which is mainly a gas spring. This results in additional holes on the fully glazed tailgate. Due to the fact as stated above, to eliminate number of holes it would be preferable to integrate some functional mechanisms in same components. Eventually it is proposed to integrate the locking component in the gas spring to reduce the number of holes. The gas spring with locking mechanism can eliminate at least one hole which along with increasing the durability and reliability of the glass would also save the processing time and cost by at least 25% for the manufacturing the glass for tailgate.

[0006] US4623132 discloses a gas spring assisted counterbalance system which is basis for many of the current hatchback mechanism in vehicles and other similar closure devices in window doors, cabinets, machines, cold storage freezers etc. However, the above mentioned patent does not disclose about locking mechanism for the gas spring.

[0007] US4309027 and US3789742 discloses pneumatic and hydraulic spring systems for locking in closed or compressed position. Both the mechanisms have the limitation of inaccessibility from outside for locking or unlocking once fixed to the tailgate, window door etc. Additionally, since the locking plane is non- perpendicular to piston rod movement the locking and/or unlocking of the gas spring mechanism by means of an external key is not possible. Similarly, many mechanisms exist for locking at the open or extended position of the gas spring.

[0008] Hence, there is a need for an improved aesthetically pleasing fully glazed openable tailgate which minimises the processing steps involving in drilling holes on the glass by combining one or more functional mechanisms and further accommodates more glazing area. Further, there is a need to provide a locking mechanism along with the gas spring mechanism with a simplified design wherein the locking and unlocking can be done by an external source.

Summary of the Disclosure

[0009] One aspect of the present disclosure provides a locking device which includes a gas spring and a locking element. The gas spring further includes a gas compressed cylinder and a piston rod. A locking element is attached on the piston rod of the gas spring. The locking element includes a key hole, a locking lever, an enclosure unit and a pin. The key hole and the locking lever is attached in the enclosure unit. The pin is attached to the cylinder of the gas spring. The key hole enables the rotation of the locking lever. This rotation enables the engagement and disengagement of the locking lever with the pin, which therein results in locking and unlocking the locking device.

[0010] In yet another aspect of the present disclosure, a locking device for a tailgate of a vehicle is provided. The locking device includes a gas spring and a locking element. The gas spring further includes a gas compressed cylinder and a piston rod. A locking element is attached or fixed on the piston rod of the gas spring. The locking element includes a key hole, a locking lever, an enclosure unit and a pin. The key hole and the locking lever is attached in the enclosure unit. The pin is attached to the cylinder of the gas spring. The key hole enables the rotation of the locking lever. This rotation enables the engagement and disengagement of the locking lever with the pin, which therein results in locking and unlocking the locking device.

[0011] In yet another aspect of the present disclosure is to provide a fully glazed tailgate having minimized number of drill holes on the tailgate glass by reducing the number of modules, or combination of two or all three functional mechanisms (locking, lifting/holding and hinging).

[0012] In yet another aspect of the present disclosure is to provide a fully glazed openable tailgate which is more cost effective.

[0013] In yet another aspect of the present disclosure is to provide a fully glazed openable tailgate with a simplified mechanism.

[0014] In yet another aspect of the present disclosure is to provide a fully glazed openable tailgate with better reliability and durability.

[0015] In yet another aspect of the present disclosure is to provide a fully glazed openable tailgate which is aesthetically pleasing and robust.

[0016] In yet another aspect of the present disclosure is to provide a fully glazed openable tailgate which is easy to open, operate and maintain.

[0017] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. Brief Description of the Drawings

[0018] Embodiments are illustrated by way of example and are not limited in the accompanying figures.

[0019] FIG. 1 illustrates a conventional prior art showing metal frame tailgate of a vehicle;

[0020] FIG. 2 illustrates a conventional prior art showing fully glazed tailgate of a vehicle; prior art

[0021] FIG. 3 illustrates (A) cross-sectional (B) isometric view of a locking device in an unlock position; according to an embodiment of the present disclosure;

[0022] FIG. 4 illustrates (A) cross-sectional (B) isometric view of a locking device in a lock position; according to an embodiment of the present disclosure;

[0023] FIG. 5 illustrates an exploded view of a locking element of the locking device; according to an embodiment of the present disclosure;

[0024] FIG. 6 illustrates a vehicle with a tailgate in (A) unlocking (B) locking positions; according to an embodiment of the present disclosure;

[0025] FIG. 7 illustrates process flow diagram showing various steps involved in locking and unlocking of the tailgate using the locking device; according to an embodiment of the present disclosure;

[0026] FIG. 8 illustrates a facade in (A) unlocking (B) locking positions; according to an embodiment of the present disclosure;

[0027] Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.

Detailed Description

[0028] The present invention is now discussed in more detail referring to the drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numbers. [0029] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. FIG. 3 illustrates the (A) isometric (B) cross-sectional view of a locking device 100 in an unlock position. FIG. 4 illustrates the (A) isometric (B) cross-sectional view of a locking device 100 in a lock position. The opening or unlocking and closing or locking can be used interchangeably in the present disclosure. The locking device 100 is provided with a gas spring and a locking element. The gas spring comprises of a gas compressed cylinder 102 and a piston rod 104. The gas spring includes a cylinder 102 which preferably contains a gas under pressure. The cylinder 102 includes a base on its one end and a seal-guide unit 118 on its other end. The gas spring also includes a piston rod 104 which is displaced axially and is positioned by the seal- guide unit 118 concentric to the cylinder 102, and a piston 106 on the piston rod 104 which divides the cylinder 102 into two working chambers. Additionally, the seal-guide unit 118 prevents leakage of gas or oil (for damped gas spring systems) within the working chambers. Optionally, the seal-guide unit 118 can have an additional function by providing sufficient clearance to allow free movement of the piston rod 104 while maintaining the concentricity and allowing flow of air. The gas spring has a piston 106 mounted on the piston rod 104 that can slide back and forth inside a cylinder 102 which is filled with pressurized gas and is completely sealed up. Preferably, nitrogen gas is used in the gas spring as it is inert, cheap and environmentally safe. Alternatively, a hydraulic spring can be used. In hydarualic spring the piston 106 movement is produced by the compression of a fluid. The fluid commonly used in such springs are water, water based solutions, mineral oil, natural oils and silicon oils. Alternatively, a mechanical spring can also be used. In a mechanical spring, the mechanism is without an internal pressure and/or with a frictional sliding between piston rod 104 and cylinder 102.

[0030] The locking element comprises of a key hole 108, a locking lever 110, an enclosure unit 122 and a pin 112. An enclosure unit 122 is provided which is attached on the piston rod 104 of the gas spring. The enclosure unit 122 is either welded or bolted to the piston rod 104 of the gas spring. The key hole 108 and the locking lever 110 are attached in the enclosure unit 122. The locking lever 110 is attached in such a way that it rotates freely inside the enclosure unit 122 without detaching from the enclosure unit 122. The key 114 engages with the key hole 108. The key 114 is rotated which in turn enables the rotation of the key hole which in turn results in rotation of the locking lever 110 inside the enclosure unit 122. A pin 112 is provided which is attached to the cylinder 102 of the gas spring for engaging and disengaging the locking lever 110. The locking lever 110 has a wedge shaped head complementing the curved surface of the pin 112 which provided on the cylinder 102. The pin 112 is wedged shape. The pin 112 is welded to the cylinder 102 opening side that is towards the seal-guide side 118 of the cylinder 102.

[0031] FIG. 5 illustrates an exploded view of a locking element of the locking device 100. The locking element comprises of a key hole 108, a locking lever 110, an enclosure unit 122 and a pin 112. The locking lever 110 inserts in the enclosure unit 122 such that the locking lever 110 can rotate freely in the enclosure unit 122. The torsional spring 120 is fixed inside the locking lever 110. The torsional spring 120 holds the locking lever 110 in the locked position. The locking lever 110 has a wedge shaped head complementing the curved surface of the pin 112 which provided on the cylinder 102. For locking device 100 in locked position, the key 114 is inserted in the key hole 108 and is rotated which therein rotates the torsional spring 120. Simultaneously the locking lever 110 slides over the pin 112, therein engaging the locking lever 110 with the pin 112 for locking the locking device 100. For unlocking the locking device 100, the key is inserted in the key hole 108 and key hole 108 is rotated against the force of the torsional spring 120. Simultaneously, the locking lever 110 is also rotated which results in disengaging of the locking lever 110 to the pin 112, therein disengaging the locking lever 110 with the pin 112.

[0032] In an embodiment, alternatively, the torsional spring 120 can be replaced by compression spring. In these cases, the locking lever 110 moves radially to the cylinder 102. The compression spring resist the radial motion of the locking lever 110. Alternatively, the locking lever 110 wedge shaped head can also be aligned radially to the cylinder 102. The radial motion is achieved by a wedge within the enclosure unit 122 which pushes the whole locking lever 110 radially outwards during the key hole 108 rotation. The pin 112 on the cylinder 102 may also be a collar to allow more area for the wedge shaped locking lever 110 head to slide easily and engage during the locking motion at the end of closing position.

[0033] In an embodiment, the actuation of locking device 100 can be either by manually or automatically. When actuation is manually it is done by using a physical key 114. Furthermore, alternatively the locking device 100 can also be actuated automatically. This is possible if the locking lever 110 is provided with electromagnetic mechanism. The locking lever 110 would be actuated by the magnetic force generated by an electromagnet powered by the power source (in case of vehicle it is car battery). The locking lever 110 can rotate and thereby unlock the locking device 100 allowing the piston rod 104 to extend. The same magnetic force can be utilized to return the locking lever 110 to the locking position when the piston rod 104 is in compressed state. The electromagnetic system can be controlled by means of a switch. The switch can communicate to the electromagnetic system by wired or wireless communication.

[0034] FIG. 6 A and FIG. 6B illustrates a locking device 100 which is attached to the body frame of the tailgate of the vehicle in an open (unlocking) and closed (locking) position respectively. Alternatively, the locking device 100 is attached to the glass of the tailgate of the vehicle. The locking device 100 is typically used to connect a motor vehicle tailgate with the C or D pillar of the motor vehicle. The gas spring on one hand is fastened rotationally to a vehicle body, and on the other hand is fastened to a vehicle tailgate which can be opened and closed. The gas spring is provided to act as a lifting mechanism for an opening range of the tailgate. The piston rod 104 end of the locking device 100 is attached to the tailgate, such that the key hole 108 is aligned with the hole in the frame / glass of the tailgate of the vehicle and the cylinder 102 end of the locking device 100 is attached to the car frame. When the tailgate is in open position the locking device is in extended position as shown in FIG. 6A. The gas pressure in the gas spring assists the tailgate to rest at this position. While closing of the tailgate, the tailgate is lowered manually and the gas spring compresses to its closed position and allows the locking lever 110 in the piston rod 104 to engage with the pin 112 in the cylinder 102, thereby, locking the tailgate. The tailgate of the vehicle is provided with at least one snap fit 116 to enable proper closure of the tailgate with the frame. The snap fit 116 is a form of interference fit provided in many equipment and utensils to enable closing of the same. Generally, the snap fit 116 consists of a slot/hole 116A on the car frame and a spherical or disc shaped pin 116B attached to the glass/frame holding the glass with a semi- flexible material. This semi-flexible joint allows the pin 116B to be pushed into the slot 116A with manual pressure created during the closing of the tailgate. The snap fit 116 is provided at the bottom of the tailgate to enable proper closure of the tailgate with the frame and improve the rigidity of the gas spring locking mechanism. The snap fit 116 can be present either in middle of the tailgate or on the side opposite of the locking device 100. Preferably, snap fit 116 is added to the opposite side of the locking device 100 to ensure the tailgate is properly closed and avoiding any imbalance created because of the locking device 100 which is positioned on one end of the tailgate rather than in centre. Alternatively, a magnetic fit is used. The magnetic fit consists of a metallic strip/plate on the glass/frame of the tailgate and a magnet or electromagnet is provided on the vehicle body. When the tailgate is closed the magnetic force between the metallic strip/plate and the magnet/electromagnet ensures the proper closure of the tailgate similar to the snap fit.

[0035] FIG. 7 illustrates a method of locking and unlocking the tailgate with locking device 100 provided with the gas spring integrated with locking element, the method includes following steps. Firstly, engaging the key 114 to the key hole 108 to rotate and disengage the locking lever 110 from the pin 112. Secondly lifting the tailgate to allow the piston rod 104 for moving out of the cylinder 102 and holding the tailgate in open position by the cylinder 102 gas pressure. Thirdly lowering the tailgate to move the piston rod 104 inside the cylinder 102 for compressing the gas, closing the tailgate and engaging the key 114 to rotate and engage the locking lever 110 to the pin 112. If lowering/pressing force is released, the pressure of the gas pushes the piston 106 back out again leading to opening of tailgate. Finally, pressing the tailgate against the frame of the car to ensure proper closing by the snap fit 116. [0036] In an embodiment, a locking device 100 can be attached to the facade of the building as illustrated in FIG. 8 A and 8B. A locking device 100 which is attached to the facade 126, window door, skylight door of the building for access from inside or outside. The facade 126 locking device 100 includes a gas spring and a locking element. The gas spring on one hand is fastened rotationally to a facade frame 124, and on the other hand is fastened to a facade 126 which can be opened and closed. The gas spring is provided to act as a lifting mechanism for an opening the facade 126. The piston rod end of the locking device is attached to the facade 126, such that the key hole 108 is aligned with the hole in the facade 126 of the building and the cylinder end of the locking device 100 is attached to the facade frame 124. The gas spring further includes a gas compressed cylinder and a piston rod. A locking element is attached/fixed on the piston rod of the gas spring. The locking element includes a key hole and a locking lever. A pin is attached to the cylinder of the gas spring for engaging and disengaging the locking lever of the locking element. The locking device 100 provides safety for any unauthorized opening of the doors or facades. The mechanism provides a means of opening the facades or doors in sealed environments to allow fresh air and/or sunlight to enter in case of AHU malfunction. Optionally, for emergency window doors, the locking mechanism can be automatic by means of electromagnetically controlled locking lever.

[0037] In an embodiment, a locking device 100 can be attached to the movable door of a luggage box. A locking device 100 which is attached to the body of the luggage box. The gas spring on one hand is fastened rotationally to the box edge, and on the other hand is fastened to a cover of the box which can be opened and closed. The gas spring is provided to act as a lifting mechanism for an opening the cover or lid of the box. The piston rod end of the locking device is attached to the cover, such that the key hole is aligned with the hole in the cover of the box and the cylinder end of the locking device 100 is attached to the box edge. The door locking device includes a gas spring. The gas spring further includes a gas compressed cylinder and a piston rod. A locking element is attached/fixed on the piston rod of the gas spring. The locking element includes a key hole and a locking lever. A pin is attached to the cylinder of the gas spring for engaging and disengaging the locking lever of the locking element.

[0038] The present disclosure has following advantages: reduced number of holes in glass, lock & lifting is combine and easy assembly using standardized parts.

[0039] Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

[0040] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

[0041] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Certain features, that are for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in a sub combination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive. [0042] The description in combination with the figures is provided to assist in understanding the teachings disclosed herein, is provided to assist in describing the teachings, and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

[0043] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0044] Also, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts.

[0046] While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

List of Elements TITLE: GAS SPRING WITH A LOCK

100 Locking Device

102 Cylinder

104 Piston Rod

106 Piston

108 Key Hole

110 Locking Lever

112 Pin

114 Key

116 Snap /Magnetic Fit

116A Slot of Snap Fit

116B Pin of Snap Fit

118 Seal-Guide Unit

120 Torsional Spring

122 Enclosure Unit

124 Facade Frame

126 Facade

Claims

We claim,

1. A locking device [100] comprising: a gas spring comprising a gas compressed cylinder [102] and a piston rod [104]; and a locking element attached on the piston rod [104] of the gas spring, wherein the locking element comprising:

a key hole [108], a locking lever [110], an enclosure unit [122] and a pin [112]; wherein

the pin [112] attached to the cylinder [102] of the gas spring; wherein the key hole [108] enables the rotation of the locking lever [110] and enables the engagement and disengagement of the locking lever [110] with the pin [112], which therein results in locking and unlocking the locking device [100].

1. The locking device [100] as claimed in claim 1, wherein the key hole

[108] and the locking lever [110] are attached in the enclosure unit [122].

2. The locking device [100] as claimed in claim 1, wherein the key hole

[108] enables the rotation of the locking lever [110] inside the enclosure unit [122].

3. The locking device [100] as claimed in claim 1, wherein a torsional spring

[120] is inserted in the locking lever [110] to hold the locking lever [110].

4. The locking device [100] as claimed in claim 1, wherein the pin [112] is wedged shape.

5. The locking device [100] as claimed in claim 1, wherein the locking device [100] can be actuated manually, automatically or combination thereof.

6. A locking device [100] for a tailgate of a vehicle comprising: a gas spring comprising a gas compressed cylinder [102] and a piston rod [104]; and a locking element attached on the piston rod [104] of the gas spring, wherein the locking element comprising:

7. The locking device [100] for a tailgate of a vehicle as claimed in claim 1, wherein the key hole [108] and the locking lever [110] are attached in the enclosure unit [122].

8. The locking device [100] for a tailgate of a vehicle as claimed in claim 6, wherein the key hole [108] enables the rotation of the locking lever [110] inside the enclosure unit [122].

9. The locking device [100] for a tailgate of a vehicle as claimed in claim 6, wherein a torsional spring [120] is inserted in the locking lever [110] to hold the locking lever [110].

10. The locking device [100] as for a tailgate of a vehicle as claimed in claim 6, wherein the pin [112] is wedged shape.

11. The locking device [100] for a tailgate of a vehicle as claimed in claim 6, wherein a hole on the tailgate is provided such that the key hole [108] is aligned with the hole of the tailgate.

12. The locking device [100] for a tailgate of a vehicle as claimed in claim 7, wherein the cylinder [102] end is attached to the body frame of the tailgate of the vehicle.

13. The locking device [100] for a tailgate of a vehicle as claimed in claim 7, wherein the piston rod [104] end is attached to the glass of the tailgate of the vehicle.

14. The locking device [100] for a tailgate of a vehicle as claimed in claim 7, wherein the locking device [100] can be actuated manually, automatically or combination thereof.

15. The locking device [100] for a tailgate of a vehicle as claimed in claim 7, wherein the tailgate is provided with at least a snap fit [116] or a magnetic fit [116] to enable proper closure of the tailgate with the frame.

16. A method of locking and unlocking the tailgate with the locking device

[100] as claimed in claim 1, the method comprising:

rotating the key hole [108] and disengaging the locking lever [110] from the pin [112];

lifting the tailgate to allow the piston rod [104] for moving out of the cylinder [102] ; holding the tailgate in open position by the cylinder [102] gas pressure; lowering the tailgate to move the piston rod [104] inside the cylinder [102] for compressing the gas;

closing the tailgate;

rotating the key hole [108] and engage the locking lever [110] to the pin [112]; and

pressing the glass against the frame at the tailgate to ensure proper closing by using the snap fit or magnetic fit [116].