A waterproof floating connector and connector assembly

Abstract

The application discloses a waterproof floating connector and a connector assembly, and belongs to the technical field of connector manufacturing. The waterproof floating connector comprises a first shell, a metal shell, an insulator, a fixed center pin and a floating conductor. One end of the fixed center pin is provided with a protruding part, the floating conductor is provided with a floating accommodating cavity and a floating window, the protruding part is accommodated in the floating window and has a gap with the side and the lower part of the window when not matched, and axial and radial floating is realized. The connector assembly comprises the waterproof floating connector as a first connector, and a second connector matched with the first connector, and the second connector comprises an inner conductor, an outer conductor and a second insulator. The application realizes matching tolerance through the floating structure, simplifies the traditional three-piece structure into a two-piece structure, reduces the overall height, optimizes impedance matching, improves high-frequency signal transmission performance, and is suitable for compact installation and high-frequency signal transmission scenes such as vehicle-mounted cameras.

Description

Technical Field

[0001] This invention relates to the field of connector manufacturing, and more particularly to a waterproof floating connector and connector assembly. Background Technology

[0002] The vehicle camera connector is used to connect the camera installed on the outside of the vehicle to the host system inside the vehicle (usually the central control screen or a dedicated image processing unit). It collects environmental data outside the car through the external camera, providing essential functions such as reversing, driving recording, and parking detection.

[0003] like Figure 13 As shown, existing automotive camera connectors typically consist of three parts: a head-end connector 1' that connects to an external camera, a board-end connector 2' that connects to the vehicle's infotainment system, and an intermediate adapter connector 3' that connects the head-end connector 1' and the board-end connector 2'. This structure requires a high board spacing, which cannot meet the space requirements of small products. Furthermore, the signal passing through the intermediate adapter can affect the stability and reliability of signal transmission to some extent. It also has a low application frequency and cannot meet the high-performance requirements at higher frequencies.

[0004] Meanwhile, in actual mating and use, because the board-end connector is fixedly soldered to the PCB board of the vehicle's infotainment system, when the intermediate adapter connector is first connected to the board-end connector and then the head connector is inserted into the intermediate adapter connector, axial or radial misalignment may occur during the mating process. In the limited operating space, it is not convenient to accurately perform the mating operation. The presence of the intermediate adapter connector further exacerbates the alignment problem during the mating process. Summary of the Invention

[0005] To address the above problems, this invention proposes a waterproof floating connector and a connector assembly.

[0006] The main contents of this invention include:

[0007] A waterproof floating connector includes a first housing and a metal outer shell disposed within the first housing; a fixing center pin is disposed within the metal outer shell via an insulator; a first sealing portion is disposed between the metal outer shell and the first housing; and a second sealing portion is disposed within the metal outer shell at the end of the insulator facing the mating connector.

[0008] The fixed center pin includes a first fixed section and a second fixed section; the second fixed section is floatingly connected to one end of the floating conductor; the other end of the floating conductor is electrically connected to the mating connector; the second fixed section includes a second main body and protrusions on both sides of the second main body; the floating conductor includes a floating main body and a floating contact part; the floating contact part is electrically connected to the mating connector.

[0009] The floating main body includes a floating receiving cavity surrounded by a floating wall. A floating window is provided on the floating wall. The second fixed section is disposed in the floating receiving cavity and the protrusion is disposed in the floating window. When not mated with the mating connector, there is a gap between the protrusion and the side and bottom of the floating window.

[0010] Preferably, each of the protrusions includes two contact planes disposed opposite to each other and a guide side; the guide side includes an arc-shaped guide surface and a planar limiting surface; the floating window is elongated.

[0011] Preferably, the upper surface of the floating wall is provided with a plurality of circumferentially arranged openings, and the openings extend axially; the plurality of openings divide the floating wall into a plurality of floating spring units, and the two floating windows are opened on two oppositely arranged floating spring units.

[0012] Preferably, at least two oppositely arranged floating spring units have their upper ends bent in the opposite direction to the floating receiving cavity and connected to a first spring arm, the first spring arm extending axially and in electrical contact with the second main body;

[0013] The first elastic arm includes a first contact segment A and a first contact segment B; one end of the first contact segment A is bent in the opposite direction and connected to the upper end face of the floating elastic piece; the first contact segment B is connected to the other end of the first contact segment A.

[0014] Preferably, auxiliary contact portions are formed on the upper sides of the second main body portion, and floating flanges are formed on the upper surface of the floating wall portion that extend radially outward.

[0015] Preferably, the first fixing segment includes a first main body and barbs formed on the first main body, and the insulator covers the barbs and part of the auxiliary contact portion by an overmolding process.

[0016] The present invention also proposes a connector assembly, including a mating first connector and a second connector, wherein the first connector is a waterproof floating connector as described above; the second connector includes a second insulator, an inner conductor is disposed within the second insulator, and an outer conductor is covered outside the second insulator; when the first connector and the second connector are mated, the outer conductor is in electrical contact with the metal shell; the floating contact portion is in electrical contact with the inner conductor.

[0017] Preferably, the second insulator includes a second insulating body and mounting through holes formed on the upper and lower end faces of the second insulating body. The mounting through holes include a mounting section for mounting the inner conductor and a funnel-shaped guide section formed above the mounting section. A clearance step is provided on the lower end face of the second insulating body.

[0018] The inner conductor includes a cylindrical second contact portion and a weld portion extending outward from the wall portion of the second contact portion; the second contact portion is disposed within the mounting section; the weld portion extends outward along the clearance step.

[0019] Preferably, the outer conductor includes a cylindrical fixing portion and a plurality of second elastic arms connected above the fixing portion; the plurality of second elastic arms have second contact protrusions that are in electrical contact with the metal casing;

[0020] The second insulating body has a plurality of protrusions spaced apart on the lower outer peripheral surface; the lower end surface of the fixing part includes a plurality of spaced welding feet and a plurality of spaced pressing feet; the protrusions separate the welding feet and the pressing feet.

[0021] Compared with the prior art, the advantages of the waterproof floating connector and connector assembly of the present invention are as follows:

[0022] (1) By configuring a floating conductor at one end of the fixed center pin, the male connector can adapt to and correct the corresponding mating deviation when mating with the mating connector, thus avoiding possible damage to the connector itself and the mating connector.

[0023] (2) The first spring arm built into the floating conductor ensures a reliable connection between the fixed center pin and the floating conductor, thus improving the reliability of this male connector;

[0024] (3) The connector assembly of the present invention adopts a two-piece structure, which has fewer parts and lower height compared with the existing vehicle camera connector, and can meet the space requirements of dense wiring in automobiles. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the waterproof floating connector of the present invention;

[0026] Figure 2 This is a cross-sectional view of the waterproof floating connector of the present invention from one perspective;

[0027] Figure 3 This is a cross-sectional view of the waterproof floating connector of the present invention from another perspective;

[0028] Figure 4 This is a schematic diagram of the waterproof floating connector of the present invention with the first housing removed;

[0029] Figure 5 Assembly diagram of the fixed center pin and floating conductor;

[0030] Figure 6 This is a schematic diagram of the structure for fixing the center pin;

[0031] Figure 7 This is a schematic diagram of a floating conductor.

[0032] Figure 8 A schematic diagram of the overall structure from one perspective of the second connector;

[0033] Figure 9 A schematic diagram of the overall structure of the second connector from another perspective;

[0034] Figure 10 This is a cross-sectional view of the second connector;

[0035] Figure 11 This is an overall cross-sectional view of the connector assembly of the present invention;

[0036] Figure 12 This is a schematic diagram of the mating process of the connector assembly of the present invention;

[0037] Figure 13 This is a structural schematic diagram of an existing vehicle-mounted camera connector;

[0038] Figure label:

[0039] 1' - Head connector; 2' - Board connector; 3' - Intermediate adapter connector;

[0040] 1-First connector; 10-First housing; 11-Metal shell; 12-Insulator; 13-Fixing center pin; 13-1-First fixing section; 13-2-Second fixing section; 130-First main body; 1300-Barb; 131-Second main body; 132-Protrusion; 1320-Contact plane; 1321-Guide side; 1321-1-Guiding surface; 1321-2-Limiting surface; 133-Auxiliary contact; 134-Auxiliary skirt; 14-Floating conductor; 140-Floating main body; 1401-Floating wall; 1402-Opening slot; 1403-Floating flange; 141-Floating contact; 142-Floating window; 143-First spring arm; 1431-First contact section A; 1432-First contact section B; 15-Second sealing part; 16-First sealing part;

[0041] 2-Second connector; 21-Second insulator; 210-Second insulating body; 2100-Mounting through hole; 2100-1-Mounting section; 2100-2-Guide section; 211-Leaning step; 212-Protrusion; 22-Outer conductor; 220-Fixing part; 221-Second spring arm part; 222-Second contact protrusion; 223-Solder foot; 224-Pressure foot; 23-Inner conductor; 230-Second contact part; 231-Solder part. Detailed Implementation

[0042] The technical solution protected by this invention will be described in detail below with reference to the accompanying drawings.

[0043] This invention proposes a waterproof floating connector and connector assembly. The waterproof floating connector is interoperable with existing board-end connectors in vehicles. Through the floating conductor, the connector exhibits a large mating tolerance in both the radial and axial directions during mating, facilitating operation in compact spaces and avoiding potential damage to the connector and board-end connector caused by hard mating. Furthermore, the connector assembly proposed in this invention eliminates the intermediate adapter connector compared to existing automotive camera connectors. It uses the waterproof floating connector and a corresponding second connector for interoperability, reducing the overall height and the signal transmission path, thereby reducing signal transmission loss and reflection, and facilitating the transmission of high-frequency signals.

[0044] Please refer to the following first. Figures 1 to 7 Specifically, the present invention proposes a waterproof floating connector, comprising a first housing 10 and a metal outer shell 11 disposed within the first housing 10; as shown Figure 2 and Figure 3As shown, in order to ensure the overall sealing and waterproofing of the connector, a stepped structure is provided inside the metal housing 11. The fixed center pin 13 is first wrapped in the insulator 12 by an encapsulation process, and then the insulator 12 is installed to the corresponding step of the metal housing 11. Next, a sealing structure is configured in the corresponding position, and finally the floating conductor 14 is configured at the end of the fixed center pin 13 facing the mating connection.

[0045] In this embodiment, a first sealing portion 16 is disposed between the metal outer shell 11 and the first housing 10. The metal outer shell 11 has a flared opening at one end near the mating connector. Correspondingly, a tail groove is provided at a corresponding position on the inner wall of the first housing 10. The first sealing portion 16 is formed between the tail groove and the outer peripheral wall of the opening of the metal outer shell 11. At the same time, a second sealing portion 15 is disposed inside the metal outer shell 11 at the end of the insulator 12 facing the mating connector. The first sealing portion 16 and the second sealing portion 15 can be sealing rings or structures formed by filling the corresponding spaces with sealant.

[0046] This invention features a floating conductor 14 at one end of the fixed center pin 13, enabling floating mating during mating with the mating connector. Please refer to... Figures 2 to 7 The following section will detail how the fixed center pin, the floating conductor, and their combination achieve floating mating.

[0047] like Figure 5 and Figure 6 As shown, the fixed center pin 13 includes a first fixed section 13-1 and a second fixed section 13-2; wherein, the first fixed section 13-1 is partially fixedly disposed within the insulator 12 and extends partially through the insulator 12 toward the end connected to the external camera. The first fixed section 13-1 includes a first main body 130 and barbs 1300 formed on the first main body. The barbs 1300 enable the fixed center pin 13 to be stably assembled with the insulator 12. The overmolding process adopts injection molding, thereby stably configuring it within the metal shell 11.

[0048] The second fixed section 13-2 is used to achieve electrical connection and floating connection with the floating conductor 14. The second fixed section 13-2 includes a second main body 131 and protrusions 132 protruding on both sides of the second main body 131. Through the protrusions 132, the fixed center pin 13 can be connected to the floating conductor 14, ensuring that the floating conductor 14 achieves floating mating while ensuring that the floating conductor 14 will not fall off the fixed center pin 13, thus ensuring a reliable connection between the two.

[0049] Specifically, such as Figure 4 and Figure 5As shown, the floating conductor 14 includes a floating body portion 140 and a floating contact portion 141. The floating body portion 140 is connected to the protrusion 132 of the fixed center pin 13, while the floating contact portion 141 extends towards the mating connector to achieve direct electrical connection with the mating connector. More specifically, the floating body portion 140 includes a floating receiving cavity surrounded by a floating wall portion 1401. A floating window 142 is provided on the floating wall portion 1401. The second fixed segment 13-2 of the fixed center pin 13 extends and is disposed within the floating receiving cavity. The connection between the two is achieved by distributing the protrusion 132 within the floating window 142. To achieve the floating effect, when not mated with the mating connector, there is a gap between the protrusion 132 and the sides and bottom of the floating window 142, so that during mating, the floating conductor 14 can float radially and axially relative to the fixed center pin 13 and the fixed mating connector. Please refer to [link to relevant documentation]. Figure 12 , Figure 12 The state change of the floating conductor 14 when a misalignment occurs during the matching process is given.

[0050] Furthermore, to ensure convenient assembly of the fixed center pin 13 and the floating conductor 14, several circumferentially arranged openings 1402 are provided on the upper end surface of the floating wall 1401, so that when the fixed center pin 13 is inserted into the floating receiving cavity from above, the floating receiving cavity has a certain elastic deformation; such as Figure 5 As shown, the opening slot 1402 extends axially; a plurality of opening slots 1402 divide the floating wall portion 1401 into a plurality of floating spring units, and floating windows 142 are provided on two opposite floating spring units, that is, the included angle between the two floating windows 142 on the circumference is 180°, so that the fixed center pin 13 can be installed in the middle position of the floating receiving cavity.

[0051] To further ensure the smooth insertion of the center pin 13, such as Figure 6 As shown, a single protrusion 132 includes two contact planes 1320 and a guide side 1321 disposed opposite to each other; the guide side 1321 includes an arc-shaped guide surface 1321-1 and a planar limiting surface 1321-2; the floating window 142 is elongated, such that the width of the floating window 142 is greater than the thickness of the protrusion 132, and its length is greater than the height of the protrusion 132, which ensures the degree of freedom of the floating conductor 14.

[0052] Furthermore, to ensure a more reliable connection between the fixed center pin 13 and the floating conductor 14, first spring arms 143 are bent in the opposite direction to the floating receiving cavity at the upper ends of at least two oppositely arranged floating spring units; the first spring arms 143 extend axially to maintain electrical contact with the second main body 131; specifically, as shown... Figure 7 As shown, two first spring arms 143 are bent in opposite directions and connected to the upper end surfaces of two floating spring units spaced 180° apart on the circumference; and the two first spring arms 143 are disposed opposite to the contact plane 1320 of the protrusion; the first spring arm 143 includes a first contact segment A1431 and a first contact segment B1432; one end of the first contact segment A1431 is bent in opposite directions and connected to the floating spring unit, and the other end is connected to one end of the first contact segment B1432, and the first contact segment B1432 extends towards the mating connector as a free end.

[0053] In addition, please refer to again Figure 5 and Figure 6 The upper sides of the second main body 131 extend outward to form auxiliary contact portions 133, and the upper end face of the floating wall portion 1401 extends radially outward to form a floating flange 1403. When the floating conductor 14 is assembled to the second fixing section 13-2 of the fixed center pin 13, the fixed center pin 13 is inserted from above the floating receiving cavity of the floating conductor 14. The floating flange 1403 and the first contact section A1431 of the first spring arm 143 can guide the insertion of the fixed center pin 13 to a certain extent. After assembly, when the connector is mated with the mating connector, that is, when the two are concentrically mated without deviation, while the first contact section B1432 of the first spring arm 143 is reliably connected to the fixed center pin 13, the auxiliary contact portion 133 can also make electrical contact with the inner wall of the floating wall portion. However, when deviation occurs during the mating process, causing the floating conductor 14 to deflect relative to the fixed center pin 13, such as Figure 12 As shown, not only may the auxiliary contact portion 133 and the floating flange 1403 be in electrical contact, but the first contact segment A1431 of the first spring arm will also be electrically connected to the contact plane 1320 of the second main body portion 131, so that the fixed center pin 13 and the floating conductor 14 can be reliably connected at multiple points during the mating process regardless of the size of the offset.

[0054] Furthermore, an auxiliary skirt 134 protrudes from the lower part of the first main body 130. The longitudinal section of the auxiliary skirt 134 is frustoconical. The upper part of the auxiliary skirt 134 is covered with glue inside the insulator 12. The second sealing part 15 is disposed between the outer peripheral wall of the auxiliary skirt 134 and the inner wall of the metal shell 11. When the fixed center pin 13 and the floating conductor 14 are concentrically assembled, there is a certain gap between the lower end face of the auxiliary skirt 134 and the floating flange 1403. When the floating conductor 14 deflects, the lower end face of the auxiliary skirt 134 may make electrical contact with the floating flange 1403, which to a certain extent ensures the connection stability between the fixed center pin 13 and the floating conductor 14 under any condition.

[0055] To reduce the overall structure of the vehicle camera connector, this application also proposes a new connector assembly, please refer to [link / reference needed]. Figures 8 to 12 The present invention proposes a connector assembly including a mating first connector 1 and a second connector 2, wherein the first connector 1 is a waterproof floating connector as described above, the first connector serving as a male connector, and the second connector 2 is fixedly soldered to the PCB board of the vehicle system as a female connector; the present invention eliminates the intermediate adapter connector 3' in the prior art, and enables the floating conductor 14 of the first connector 1 to be directly electrically connected to the second connector 2, thereby simplifying the signal transmission path to avoid loss and reflection, and improving high-frequency transmission capability.

[0056] Specifically, such as Figures 8 to 10 As shown, the second connector 2 includes a second insulator 21, an inner conductor 23 is disposed inside the second insulator 21, and an outer conductor 22 is covered outside the second insulator 21; when the first connector 1 and the second connector 2 are mated, the outer conductor 22 is in electrical contact with the metal shell 11; the floating contact portion 141 of the floating conductor 14 is in electrical contact with the inner conductor 23.

[0057] More specifically, the second insulator 21 includes a second insulating body 210 and mounting through holes 2100 extending through the upper and lower end faces of the second insulating body 210. The mounting through hole 2100 includes a mounting section 2100-1 for mounting the inner conductor and a funnel-shaped guide section 2100-2 formed above the mounting section 2100-1. Through the setting of the guide section 2100-2, the floating contact 141 is guided to smoothly mate into the mounting section 2100-1 and electrically connect with the inner conductor 23.

[0058] like Figure 9As shown, the inner conductor 23 includes a cylindrical second contact portion 230 and a welding portion 231 extending outward from the wall of the second contact portion 230; wherein, the second contact portion 230 is disposed within the mounting section 2100-1; and a clearance step 211 is provided on the lower end face of the second insulating body 210; the welding portion 231 fits against the clearance step and extends outward along the clearance step 211, that is, the welding portion 231 adopts a bending design to reduce the bottom contact area of ​​the inner conductor, optimize the coplanarity with the outer conductor 22, and also prevent solder paste from flowing back into the mounting through hole 2100 along the bottom during soldering with the PCB board, thus affecting the mating.

[0059] Please combine Figure 8 and Figure 9 The outer conductor 22 includes a cylindrical fixing part 220 and a plurality of second elastic arms 221 connected above the fixing part 220; the plurality of second elastic arms 221 have second contact protrusions 222 that are electrically in contact with the metal shell 11; by providing a plurality of second elastic arms 221, during the mating process, when the second elastic arms 221 contact the inclined inner wall of the metal shell 11, they can retract as the mating is initiated, which to a certain extent plays a role in mating guidance, ensuring that the floating conductor 14 can smoothly abut against the guide section 2100-2 of the second insulator 21.

[0060] To ensure stable assembly of the outer conductor 22 and the second insulator 21, a plurality of protrusions 212 are spaced apart below the outer peripheral surface of the second insulating body 210. The lower end face of the fixing part 220 includes a plurality of spaced solder feet 223 and a plurality of spaced pressure feet 224. The solder feet 223 and pressure feet 224 are separated by the protrusions 212. First, the inner conductor 23 is pressed into the second insulator 21. By forming a barb structure on the outer circumference of the inner conductor, it is press-fitted into the second insulator 21, ensuring reliable installation of both. Then, the second insulator 21 is installed into the outer conductor 22. By riveting and fixing the pressure feet 224 of the outer conductor to the bottom end face of the second insulator 21, the second connector 2 is obtained.

[0061] like Figure 11 and Figure 12 As shown, when the first connector 1 and the second connector 2 are mated, the fixed center pin 13 is electrically connected to the inner conductor 23 through the floating conductor 14, while the metal shell 11 is electrically connected to the outer conductor 22. This not only simplifies the overall structure but also enables floating connection during mating. By simplifying the signal transmission path, it facilitates the transmission of high-frequency signals and reduces signal transmission loss and reflection.

[0062] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A waterproof floating connector, characterized in that, The device includes a first housing and a metal outer shell disposed within the first housing; a fixing center pin is disposed within the metal outer shell via an insulator; a first sealing portion is disposed between the metal outer shell and the first housing; and a second sealing portion is disposed within the metal outer shell at the end of the insulator facing the mating connector. The fixed center pin includes a first fixed section and a second fixed section; the second fixed section is floatingly connected to one end of the floating conductor; the other end of the floating conductor is electrically connected to the mating connector; the second fixed section includes a second main body and protrusions on both sides of the second main body; the floating conductor includes a floating main body and a floating contact part; the floating contact part is electrically connected to the mating connector. The floating main body includes a floating receiving cavity surrounded by a floating wall. A floating window is provided on the floating wall. The second fixed section is disposed in the floating receiving cavity and the protrusion is disposed in the floating window. When not mated with the mating connector, there is a gap between the protrusion and the side and bottom of the floating window.

2. The waterproof floating connector according to claim 1, characterized in that, Each protrusion includes two opposing contact planes and a guide side; the guide side includes an arc-shaped guide surface and a planar limiting surface; the floating window is elongated.

3. A waterproof floating connector according to claim 2, characterized in that, The upper surface of the floating wall is provided with a plurality of circumferentially arranged openings and grooves that extend axially; the plurality of openings and grooves divide the floating wall into a plurality of floating spring units, and two floating windows are provided on two opposite floating spring units.

4. A waterproof floating connector according to claim 3, characterized in that, At least two opposing floating spring units have their upper ends bent in the opposite direction to the floating receiving cavity and connected to a first spring arm; the first spring arm extends axially and is in electrical contact with the second main body; The first elastic arm includes a first contact segment A and a first contact segment B. One end of the first contact segment A is bent in the opposite direction and connected to the upper end face of the floating elastic piece, and the first contact segment B is connected to the other end of the first contact segment A.

5. A waterproof floating connector according to claim 3, characterized in that, Auxiliary contact portions are formed on the upper sides of the second main body portion, and the auxiliary contact portions are electrically connected to the inner wall of the floating wall portion; The upper end face of the floating wall extends radially outward to form a floating flange.

6. A waterproof floating connector according to claim 5, characterized in that, The first fixing segment includes a first main body and barbs formed on the first main body, and the insulator is coated with the barbs by an overlay process.

7. A connector assembly, characterized in that, The device includes a first connector and a second connector for mating. The first connector is a waterproof floating connector as described in any one of claims 1 to 6. The second connector includes a second insulator, in which an inner conductor is disposed, and an outer conductor is covered on the outside of the second insulator. When the first connector and the second connector are mated, the outer conductor is in electrical contact with the metal shell. The floating contact portion makes electrical contact with the inner conductor.

8. A connector assembly according to claim 7, characterized in that, The second insulator includes a second insulating body and mounting through holes formed on the upper and lower end faces of the second insulating body. The mounting through holes include a mounting section for mounting the inner conductor and a funnel-shaped guide section formed above the mounting section. A clearance step is provided on the lower end face of the second insulating body. The inner conductor includes a cylindrical second contact portion and a weld portion extending outward from the wall portion of the second contact portion; the second contact portion is disposed within the mounting section; the weld portion extends outward along the clearance step.

9. A connector assembly according to claim 8, characterized in that, The outer conductor includes a cylindrical fixing part and a plurality of second spring arms connected above the fixing part; the plurality of second spring arms have second contact protrusions that are in electrical contact with the metal housing; the metal housing has an inclined inner wall at the opening facing the second connector.

10. A connector assembly according to claim 9, characterized in that, The second insulating body has a plurality of protrusions spaced apart on the lower outer peripheral surface; the lower end surface of the fixing part includes a plurality of spaced welding feet and a plurality of spaced pressing feet; the protrusions separate the welding feet and the pressing feet.

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