DESCRIPTION

CONTACT WITH LATCH RELEASE

The invention relates to a contact for contacting a contact according to the preamble of claim 1. A contact which has a latch release with a locking surface is known from EP 0

821 438 Al. The contact is inserted into a contact housing, the latch release swinging upwards in the inserted position, reaching a position on a retaining surface of the contact housing. The latch release prevents unintentional removal of the contact from the contact housing. The latch release is constructed in the form of a rectangular plate which is connected to the contact body via a bent edge.

A contact with a latch release is known from EP 0 547 396 Bl. The latch release is substantially constructed as a rectangular plate, which is connected to a contact body via a forming edge. The latch release is also embossed, which makes it difficult for the latch release to buckle inwards. When the contact is assembled the latch release is held against a positioning surface of a contact housing, so that it is more difficult to remove the contact from the contact housing unintentionally through the locking effect of the latch release.

A tube socket contact is known from the US patent US 2,071,699 that discloses a combination of an open ended housing made of insulating material and having a smooth continuous inner wall, a gripping finger extending longitudinally within the housing and secured to the closed end thereof . Abutments on said finger adjacent to the ends thereof and in direct engagement with the wall of the housing are disposed, and a pair of contact points spaced longitudinally on said finger intermediate of said abutments for engaging and gripping an inserted object. The outer abutments are in a sliding engagement with the inner wall of the housing. The fingers are made from strips.

Furthermore, a German patent DE 21 43 456 discloses a contact spring made of a metal stripe with a first broad end for wiring a wire wrap and a second smaller end, wherein between the smaller end and the broader end a fanfold section is disposed. Two of these contact springs are disposed to contact a printed circuit board with the fanfold section.

The German patent application DE 22 49 705 discloses an electrical socket contact in one piece. The socket contact comprises contact stripes that are arranged in a contact sleeve, whereby the contact stripes are bent in a middle section to a middle axis of the contact sleeve.

The US patent US 6,672,910 B2 discloses a contact having a contact spring, with a contact housing with contact springs having resilient contacts. The contact springs comprise double contact arms that extend from a frame. Each contact arm is symmetrical

with respect to a mirror axis arranged between the contact arms. The contact arms have a wave-like structure for containing contact pins.

The object of the invention is to provide a contact with spring contacts that enables better contacting.

The object of the invention is achieved by the contact according to claim 1.

Further advantageous embodiments of the invention are stated in the dependent claims.

One advantage of the contact according to the invention is that four spring contacts are arranged, two spring contacts being arranged opposite each contact region. In this way the contact region is encompassed on four sides by spring contacts. Furthermore each spring contact has two contact points, the contact points of the spring contacts being arranged in two contact planes one behind the other. Thus improved contact is established with eight contact points in two contact planes on four sides of the contact region. The spring contacts have a plate-shaped, extended tongue shape. The spring contacts abut the contact region with one lateral face, the width of the lateral face of the spring contacts between two contact points varying and being greater than in the region of the contact points. Thus increased spring rigidity is achieved, the contact points also having a smaller distance between them. It is thus possible to form small contact regions which can be reliably contacted with the contact points and also there is a relatively high degree of spring contact rigidity.

In one embodiment the contact points are constructed in the form of bent sections leaning inwards. The construction of the contact points in the form of bent sections enables a cost-effective and simple manufacture of the contact points. In another preferred embodiment the width of the lateral face of a spring contact increases symmetrically on both sides of a contact point. This also supports the function of the spring contacts, which is to closely abut a contact region from four sides and also provide an adequate spring rigidity.

The invention is described in more detail below with reference to the drawings, in which:

Fig. 1 is a perspective illustration of a contact,

Fig. 2 is a side view of a contact arrangement,

Fig. 3 is a front view of the contact arrangement,

Fig. 4 is a plan view of the contact arrangement, Fig. 5 is a stamping of a contact arrangement,

Fig. 6 is a side view of the contact,

Fig. 7 is a contact inside a contact housing,

Fig. 8 is a cross-section through the contact,

Fig. 9 is a cross-section through a contact plane,

Fig. 10 is a cross-section through another contact plane, Fig. 11 is a cross-section through another contact, Fig. 12 is a side view of the other contact, Fig. 13 is a plan view of two stampings, from which a contact of Figs. 11 and 12 can be made, and

Fig. 14 is a cross-section through the other contact.

Fig. 1 shows a contact 1 drawn in perspective, which consists substantially of a contact body 2 and a contact arrangement 3. The contact arrangement 3 is inserted between two side walls 14, 16 of the contact body 2. An upper face of the contact 1 is covered by a latch release 9. The latch release 9 is arranged between the two side walls 14, 16 and serves to lock the contact inside a contact housing 17 (Fig. 7). The latch release 9 is fixed to an aperture frame 6, which is positioned on front faces of the contact body 2. The aperture frame 6 forms an insertion aperture for a plug connection, which is to be electrically connected to the contact.

Opposite the aperture frame 6 the contact body 2 has first mounting lugs 25 and second mounting lugs 26. The contact body 2 and the contact arrangement 3 are made from metallic conductive material. The first mounting lugs 25 serve to clamp a conductor insulation of a conductor cable. The second mounting lugs 26 serve to clamp and to electrically contact the conductive wires of the conductor cable. Thus an electrically conductive connection is established between a conductor cable, the contact body 2 and the contact arrangement 3.

The contact arrangement 3 and the contact body 2 are attached to each other rigidly by welding points. The first side wall 14 has an aperture 13 in the region of the latch release 9, in which a first retaining lug 10 engages. The first retaining lug 10 and the latch release 9 are constructed as one piece. The first retaining lug 10 is preferably positioned on an upper edge 33 of the aperture 13. A second retaining lug 7 is constructed on the latch release 9, opposite the first retaining lug 10, and engages in a recess 15 (Fig. 6). The aperture 13 has a right side edge 32 which is assigned to a rear side edge of the first retaining lug 10. Because the first retaining lug 10 engages in the aperture 13 the latch release 9 is secured and clamped onto a locking surface 29 by the first retaining lug 10, preventing displacement through an effect of force. Furthermore the aperture 13 has the upper side edge 33, which restricts a maximum upwards deflection of the latch release. The aperture 13 furthermore has a lower side edge 34 on which the first retaining lug 10 is positioned upon maximum deflection of the latch release 9 towards the contact body 2. The aperture 13 and the first retaining lug 10, the recess 15 and the second retaining lug 7 are preferably arranged in relation to one another so that when the latch release 9 is at a fixed maximum deflection towards the contact body 2, the first retaining

- A - lug 10 and the second retaining lug 7 are positioned at the same time on the lower side edge 34 of the aperture 13 and the lower edge 30 is positioned on the recess 15 (Fig. 6). Thus the deflection of the latch release 9 is restricted symmetrically towards the contact body 2, i.e. towards the assembly position. Fig. 2 is a side view of the contact arrangement 3. The contact arrangement 3 consists substantially of four first, second, third and fourth spring contacts 4, 5, 43, 44 arranged symmetrically about a centre axis. The spring contacts 4, 5, 43, 44 are wave- shaped in construction and configured symmetrically about the centre axis of a contact region 45. Tips of the spring contacts 4, 5, 43, 44 are fixed on four sides of the square aperture frame 6. Furthermore the spring contacts 4, 5, 43, 44 are bent inwards from the aperture frame 6 in a first section 53 towards the centre axis of the contact region 45. The first section 53 extends from the aperture frame 6 up to a first contact section 57 inside which the first contact point 47 is constructed. From the first contact section 57 the spring contact is constructed to bend outwards again in a second section 54. The second section 54 ends in a region of a maximum width 48 of the spring contact. From the maximum width 48 the spring contact is again bent in the direction of the centre axis of the contact region 45 and merges with a second contact section 58, in which the second contact point 49 is constructed. The first and the second contact point 47, 49 are constructed in the form of bent sections bent inwards towards the centre axis of the contact region 45. The spring contact bends outwards slightly in a third section 55 connecting to the second contact section 58 and has a rectangular, plane tip 50. A free end 51 of the tip 50 bends inwards towards the centre axis of the contact region 45. This can be seen clearly in Fig. 2 looking at the first spring contact 4. The second, third and fourth spring contacts 5, 43, 44 are constructed identically to the first spring contact 4 and arranged on the four sides of the contact region 45. Thus the first and the second contact point 47, 49 of each spring contact are constructed in the form of bent sections bent inwards. The spring contacts substantially have a plate-shaped, extended tongue shape, the width of the lateral faces of the spring contacts between two contact points varying and being larger between the contact points than in the region of the contact points. In another embodiment the width of the lateral faces of the spring contacts increases symmetrically on both sides of a contact point 47, 48 and a contact section 57, 58. The spring contacts 4, 5, 43, 44 provide a four-sided contacting of a plug connection, which is inserted through the aperture frame 6 in the contact 1 into the contact region 45. The latch release 9 is fixed on an upper side of the aperture frame 6 at a first end region. Starting at the first end region the latch release 9 is arranged almost parallel to the aperture frame 6. The latch release 9 bends upwards at a predetermined distance from the aperture frame 6 and merges with a sliding section 27. The sliding section 27 in turn merges with a second tip 28, which is arranged almost parallel to the aperture frame 6. A locking surface 29 is constructed on the second tip 28 on a front face opposite the aperture frame 6.

The first and the second retaining lugs 10, 7 are moulded onto opposite longitudinal sides of the second tip 28. The first, the second, the third and the fourth spring contacts 4, 5, 43, 44 reach beyond the tip of the latch release 9. The second retaining lug 7 goes downwards from the second tip 28 towards the first spring contact 4. The second retaining surface 7 has a step 8 extending from its side at a predetermined distance from the second tip 28. The step 8 widens the second retaining lug 7. The step 8 projects beyond the second tip 28 in the longitudinal direction of the latch release 9.

Fig. 3 shows the contact arrangement 3 from the front, i.e. from the side of the locking surface 29. It can be seen that the first retaining lug 10 is constructed level with the second tip 28. The second retaining lug 7 also comes out of the side of the second tip 28 and is bent downwards by 90°. The four spring contacts 4, 5, 43, 44 encompass the contact region 45 on four sides, two sides respectively being arranged parallel to each other and two sides respectively perpendicular to the other two sides.

Fig. 4 shows the contact arrangement 3 from above. The latch release 9 is connected to the upper face of the aperture frame 6 via fixing points 12. The fixing points 12 are welding points for example. The latch release 9 has an embossing 42 which increases the rigidity of the latch release 9.

The first and the second retaining lugs 7, 10 come out of the second tip 28 at the same height on opposite long sides. Furthermore it can be seen clearly that the step 8 projects forward beyond the locking surface 29.

Fig. 5 shows a stamping of a contact arrangement 3 with a first, a second, a third and a fourth spring contact 4, 5, 43, 44 and a latch release 9 connected thereto. The first, second, third and fourth spring contacts 4, 5, 43, 44 are constructed identically. From an end region 46 the width of the spring contacts tapers symmetrically up to the first contact section 57, in which the first contact point 47 is constructed. The lateral face of the spring contact widens again symmetrically from the first contact section 57 towards a free end of the spring contact up to the maximum width 48. The width of the lateral face of the spring contact tapers symmetrically from the maximum width 48 towards the free end of the spring contact up to the second contact section 58, in which the second contact point 49 is constructed. The width of the lateral face of the spring contact increases symmetrically again from the second contact section 58 up to a tip 50. The tip 50 extends to just before the free end 51 of the spring contact, the free end 51 having a section tapering symmetrically to the end.

Each spring contact 4, 5, 43, 44 is plate shaped in one piece and has an extended tongue shape.

The spring contacts 4, 5, 43, 44 are configured symmetrically to a central longitudinal axis 52. Thus the spring contacts 4, 5, 43, 44 have an identical form along the longitudinal axis 52.

A contact arrangement 3 according to Fig. 2 is achieved by the stamping illustrated in Fig. 5, in that the stamping is bent and pressed into the corresponding shape.

Fig. 6 is a view of the contact 1 from the side of the second side wall 16. The second side wall 16 has the recess 15 in the region of the second retaining lug 7. The recess 15 is formed so that the second retaining lug 7 can spring into the recess 15 when the latch release 9 is pressed down. The second retaining lug 7 can thus be arranged above the second side wall 16 without preventing a permissible movement of the latch release 9.

The recess 15 has a lower edge 30 which serves as a stop for the second retaining lug 7.

The lower edge 30 restricts the maximum deflection of the latch release 9 downwards towards the first spring contact 4 (Fig. 2). Furthermore the recess 15 has a left side edge 31 which is associated with a left side edge of the second retaining lug 7. The second retaining lug 7 preferably goes partially into the recess 15 already when the latch release 9 is locked, hi this position the left side edge 31 of the recess 15 limits a longitudinal movement of the latch release 9. The latch release 9 is thus held fast by the left side edge 31 of the recess 15 against an effect of pressure onto the locking surface 29 and a displacement or buckling of the latch release 9 is prevented up to an increased force.

Fig. 7 is a cross-section of a contact housing 17 into which the contact 1 is inserted. The contact housing 17 has a contact aperture 18 on a left side. The contact aperture 18 serves to insert the plug connection into the aperture frame 6 to contact the plug connection to the spring contacts 4, 5, 43, 44. The contact housing 17 has an insertion aperture 19 opposite the contact aperture 18. During assembly the contact 1 is first inserted with the aperture frame 6 into the contact housing 17 via the insertion aperture 19. The contact housing 17 has a first reception cavity 35 next to the insertion aperture 19, which leads into an intermediate region 36 via a tapered chamfer 23. The tapered chamfer 23 projects from the upper side of the contact housing 17 into the reception cavity 35. The intermediate region 36 has a lower height than the first reception cavity 35. The intermediate region 36 widens via a second step 37 to a second reception cavity 38. The second reception cavity has a greater height than the intermediate region 36. The upper side of the contact housing 17 has an assembly aperture 39 above the second reception cavity 38. The second reception cavity 38 tapers over a further step to a contact cavity 40. The contact cavity 40 is connected to the contact aperture 18.

When assembled the aperture frame 6 and part of the contact body 2 are arranged inside the contact cavity 40. The contact cavity 40 has substantially the same cross- section as the inserted contact 1. The sliding section 27 and the second tip 28 of the latch release 9 are arranged inside the second reception cavity 38. The front end of the locking surface 29 of the latch release 9 is associated with the second step 37. The step 8 is positioned on a lower side of a retaining block 41 which has the tapered chamfer 23.

To assemble the contact 1 the contact 1 and the aperture frame 6 are pushed into the insertion aperture 19 of the contact housing 17. The cross-section of the first reception cavity 35 is designed so that the contact 1 can be pushed into the reception cavity 35 as

far as the sliding section 27. If the contact 1 is pushed further into the insertion aperture 19 then the sliding section 27 of the latch release 9 slides along the tapered chamfer 23. The latch release 9 is pushed down towards the contact body 2 in the process so that the contact 1 can be pushed further through the intermediate region 36 up to the stop at the end of the contact cavity 40. If the locking surface 29 reaches the second reception cavity 38 then the latch release 9 springs upwards, the step 8 of the second retaining lug 7 being positioned on a lower positioning surface 21 of the retaining block 41. Furthermore the front end of the locking surface 29 is positioned front end on the second step 37. During the whole insertion procedure the first retaining lug 10 remains in the aperture 13. The height of the aperture 13 is designed such that the latch release 9 can be pressed so far down that the latch release 9 can be pushed through underneath the retaining block 41.

If the contact 1 is now pulled backwards by a cable, which is rigidly connected to the contact 1 via the first and the second mounting lugs 25, 26, then the locking surface 29, which is arranged parallel to the step 37, is pressed against the step 37. In this position a longitudinal force is exerted onto the latch release 9 along the second tip 28 of the latch release 9. There is a danger that the latch release 9 could buckle. The latch release 9 is held in the locked position by the second retaining lug 7, which is supported against the left side edge 31 of the recess 15, and by the first retaining lug 10, which is stretched against the right side edge 32 of the aperture 13. The second tip 28 is thus braced on both sides with the contact body 2 and the latch release 9 can hardly be bent. By positioning the step 8 on the underneath of the retaining block 41 the position of the latch release 9 is adjusted furthermore in relation to the retaining block 41. It is hardly possible for the contact 1 to tilt in the process in relation to the retaining block 41. The latch release 9 is furthermore retained in the aperture 13 by the first retaining lug 10, preventing it bending upwards. This makes it harder to unintentionally pull the contact 1 out of the insertion aperture 19.

If the contact 1 is to be removed from the contact housing 17 again then the latch release 9 is pressed down towards the contact body 2 via the assembly aperture 39 with an assembly tool until the upper face of the second tip 28 is positioned underneath the positioning surface 21 of the retaining block 41. Then the contact 1 is pulled out of the insertion aperture 19 by the cable fixed to the contact 1.

Fig. 8 is a cross-section through the longitudinal centre axis of the contact 1. In it the arrangement of the first and the second contact planes in the region of the first and second contact sections 57, 58 with the first and second contact points 47 and 49 can be seen clearly. Furthermore it is clearly shown that the spring contacts 4, 5, 43, 44 are of tapered construction in the region of the contact points 47, 49 and encompass the contact region 45 tightly.

Fig. 9 is a cross-section through a second contact plane of the second contact points 49 of the contact 1. The four second contact points 49 of the four spring contacts 4, 5, 43, 44 abut the contact region 45 on four lateral faces of the contact region 45. The

second contact points 49 also have rounded inner surfaces 56 which abut the contact region and are curved towards the centre axis of the contact region 45. Every other contact point 49 of the spring contacts is preferably rounded on the inner side 56. The contact region 45 is thus enclosed even more tightly on the four sides. Fig. 10 is a cross-section through the first contact plane, which is enclosed by four first contact points 47 of the four spring contacts. The first contact points 47 also project inwards and are rounded on one inner side 56. Thus a tight enclosure of the contact region 45 in the first contact plane is achieved.

Fig. 11 is a cross-section through another contact 59 which in contrast to the contact 1 of Fig. 1 is constructed in one piece. The other contact 59 has a housing 75 with four further spring contacts 60, 61, 62 leading from housing sides 64 via bent sections 65 into the housing. The bent sections 65 are arranged on four side edges of a square insertion aperture 66. The insertion aperture 66 serves to receive a plug connection. The further spring contacts 60, 61, 62, 63 are of substantially identical construction and abut four sides of a contact region 45. The further first spring contact 60 has a first further section 67 in which the further first spring contact 60 is bent towards a centre axis of the contact region 45. The further first section 67 merges with a first further contact point 71. Starting from the first further contact point 71 the further first spring contact 60 in a further second section 68 goes from the centre axis of the contact region 45 upwards back to a cusp 72. Starting from the cusp 72 the further first spring contact 60 goes in a further third section 69 to a further second contact point 73 towards the centre axis of the contact region 45. Starting from the further second contact point 73 the further first spring contact 60 goes away in a further fourth section 70 upwards from the centre axis of the contact region 45. In a further end region 74 the further first spring contact 60 is positioned on a housing side 64 of the further contact 59.

The further second, third and fourth spring contacts 61, 62, 63 are of identical construction to the further first spring contact 60, every other respective further spring contact being arranged mirror-symmetrically to the centre axis of the contact region 45 and the four further spring contacts 60, 61, 62, 63 abutting the contact region 45 on four sides. In this way a contact region 45 is established, which has two contact planes, in which four further first contact points 71 and four further contact points 73 are respectively arranged.

Fig. 12 is a side view of the other contact 59, a further latch release 76 projecting upwards beyond an upper housing side. A protecting edge 77 is formed on a lateral housing side and goes beyond the upper housing side and protects and covers the side of the further latch release 76. The protecting edge 77 preferably has the same length as the lateral housing side and starting from the lateral housing side goes up to a height at which the further latch release 76 finishes. The further latch release 76 is thus covered laterally by the protecting edge 77 along its full height and width.

Fig. 13 shows another stamping 78 from which another contact 59 of Figs. 11 and 12 can be produced with the help of bending processes. The other stamping 78 has a housing section 80 to which a first mounting section 81 is connected. A second mounting section 82 connects to the first mounting section 81. The second mounting section 82 has the basic form of first mounting lugs 25. The first mounting section 81 has the basic form of second mounting lugs 26.

Four contact lugs 83, 84, 85, 86 are arranged on an opposite end of the housing section 80. The first, second, third and fourth contact lugs are constructed identically. From an end region the width of the contact lug tapers symmetrically up to the first contact section, in which the first contact point will be constructed. The lateral face of the contact lug widens again symmetrically from the first contact section towards a free end of the contact lug up to the maximum width. The width of the lateral face of the contact lug tapers symmetrically from the maximum width towards the free end of the contact lug up to the second contact section, in which the second contact point will be constructed. The width of the lateral face of the contact lug increases symmetrically again from the second contact section up to a tip. The tip extends to just before the free end of the contact lug, the free end having a section tapering symmetrically to the end. Thus, the contact lugs may have the same shape as the spring contacts of figure 5. The four contact lugs are bent back in corresponding bending processes, to construct the further first, second, third and fourth spring contacts 60, 61, 62, 63.

Two grooves 87, 88 are introduced inside the housing section 80 and are arranged parallel to the longitudinal direction of the contact lugs 83, 84, 85, 86. The first groove 87 is arranged between the first and the second contact lugs 83, 84 from a longitudinal aspect. The second groove 88 is between the second and third contact lugs 84, 85 from a longitudinal aspect. Furthermore the housing section 80 has a moulded part 89 for the further latch release 76.

To produce the other contact 59 the contact lugs 83, 84, 85, 86 are bent into the form illustrated in Fig. 11. The further sections 76, 78, 79, 70 are produced in the process with the further first and second contact points 79, 73. Then the housing section 80 is bent around a first, second and third bent edge 90, 91, 92, the first bent edge 90 being constructed along a centre axis of the first groove 87. and the second bent edge 91 along a centre axis of the second groove 88, to produce the housing 75 with the further spring contacts 60, 61, 62, 63 inside. The third bent edge 92 is arranged parallel to the longitudinal direction of the contact lugs 83, 84, 85, 86 and constructed in the centre between the third and fourth contact lugs 85, 86. Thus a housing 75 is achieved that has a substantially rectangular form, as illustrated in Fig. 14. Fig. 14 is a cross-section through a first contact plane with the housing section 75 and the further first contact points 71. Furthermore the moulded part 89 is embossed according to Fig. 11 to the further latch release 76.