WO2011106935A1

WO2011106935A1 - Screw support for securing a plurality of screws

Info

Publication number: WO2011106935A1
Application number: PCT/CN2010/070861
Authority: WO
Inventors: Olsson Fredrik
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2010-03-04
Filing date: 2010-03-04
Publication date: 2011-09-09
Also published as: CN102301535B; CN102301535A

Abstract

A screw support for securing a plurality of screws is provided, the screw support comprising: a first flat member(111) with a first recess(113) for accommodating a first screw, the first recess(113) being formed to prevent the first screw from slipping out of the first recess upon insertion; a second flat member(115) with a second recess(117) for accommodating a second screw, the second recess being formed to prevent the second screw from slipping out of the second recess upon insertion; and a joining member(118) for flexibly joining the first flat member(111) with the second flat member(115).

Description

A screw support for securing a plurality of screws

BACKGROUND OF THE INVENTION

The present invention relates to the field of electrical screw connectors.

In the installation of the remote radio units and other outdoor telecom units, problems have been reported that the screws to the grounding cable lug have been dropped or lost during the transportation or installation of the unit. The screws shall therefore be tightened carefully. Further, in some countries, also regulations exist which prescribe attaching the grounding cable with two

independent screws. The grounding contact and screw clamping force must be kept also when the unit has been installed in a site during long time, several years.

SUMMARY OF THE INVENTION

A goal to be achieved by the present invention is to provide a concept for efficiently securing screws, in particular grounding screws in telecommunication equipment.

According to an aspect, the invention relates to a screw support for securing a plurality of screws. The screw support comprises a first flat member with a first recess for accommodating a first screw, the first recess being formed to prevent slipping out of the first screw upon insertion, a second flat member with a second recess for accommodating a second screw, the second recess being formed to prevent slipping out of the second screw upon insertion, and a joining member for flexibly joining the first flat member with the second flat member. Preferably, the joining member is elastic in order to enable a flexible screw adjustment. According to an implementation form, the screw support further comprises a first washer rotatable arranged in the first recess, and a second washer rotatable arranged in the second recess, the first washer being formed for accommodating the first screw, the second washer being formed for accommodating the second screw. According to an implementation form, the first washer and the second washer respectively comprise a circular groove being formed in the respective outside wall of the respective first and second washer, and wherein the first recess and the second recess respectively comprise a circular elevation respectively engaging in the respective circular groove.

According to an implementation form, the washer may respectively have an inside thread, and wherein the screws are screwed or inserted into the washers. Thus, screws, e.g. captive screws, may be kept in the washers by the recess in the upper part of the thread. According to an implementation form, the flat members hold the washer, wherein the washer are adapted for holding the screws.

According to an implementation form, the first flat member and the second flat member respectively comprise radially extending cuts defining a plurality of resilient members for preventing slipping out of the first screw or of the second screw.

According to an implementation form, the joining member is U-formed, wherein a distance between the respective end of the joining member and the top of the joining member is greater than or equal to a distance between centers of the first and second recess. According to an implementation form, the joining member is U-formed, wherein the first flat member and the second flat member are arranged at the respective end of the joining member.

According to an implementation form, the first flat member, the second flat member and the joining member are integrally formed. According to an implementation form, the screw support further comprises a securing strap extending from the first flat member or from the second flat member, the securing strap comprising a recess for receiving a securing screw.

According to an implementation form, the first flat member, the second flat member and the joining member are made of an elastic material, in particular of silicone, rubber or plastic or spring steel. According to a further aspect, the invention relates to a grounding screw arrangement comprising the screw support, a first grounding screw being hold in the first recess of the first flat member, and a second grounding screw being hold in the second recess of the second flat member. According to a further aspect, the invention relates to an electric arrangement comprising a casing for accommodating an electric component; and a grounding cable comprising a cable lug, the cable lug being connected to the casing by the grounding screw arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

Further implementation forms will be described with reference to the following Figures, in which: Fig. 1 shows an implementation form of a grounding screw

arrangement;

Figs. 2a to 2c show an implementation form of a utilization of a grounding screw arrangement;

Fig. 3a to 3c show an implementation form of a grounding screw

arrangement;

Fig. 4 shows an implementation form of a grounding screw su

DETAILED DESCRIPTION

Fig. 1 shows an implementation form of a grounding screw arrangement comprising a screw support 101 , a first washer 103, a second washer 105, a first screw 107 and a second screw 109. The screws 107 and 109 may be captive screws, by way of example. The screw support 101 comprises a first flat member 111 having a first recess 113, and a second flat member 115 having a second recess 117. The flat members 111 and 113 are flexibly joined by a joining member 118, which may be U-shaped. The flat members 111 and 115 are respectively arranged to accommodate the respective washer 103 and 105. The washer 103 and 105 may, respectively comprise at least one circular, 360 degree groove 119, 121 being respectively formed in the outside walls of the respective washer 103 and 105. The washers 103 and 105 may have internal threads, wherein a thread dimension may

correspond to the screw's threads.

Optionally, the screw support 101 may comprise a securing strap 123 outwardly extending from e.g. the first flat member 111. At its end, the securing strap 123 comprises a flat member 125 with a recess 127 for receiving e.g. a securing screw.

The screw support 101 may be utilized to connect a cable lug 129 of a ground cable 131 to e.g. a casing of an electrical component which is not shown in Fig. 1.

Figs. 2a to 2c show a utilization of the grounding screw arrangement of Fig. 1. By way of example, the washers 103 and 105 are first inserted into the respective recess 113 and 117 of the screw support 101 as shown in Fig. 2a. The flexibility of screw support 101 , which may be formed as a flexible strap, enables to

respectively press the washers 103 and 105 into the respective recess 113 and 117. The washers 103 and 105 are then locked in axial direction by means of the grooves 119 and 121. However, the washers 103 and 105 are not locked for rotation of the washers 103 and 105 in the recesses 113 and 117. Thereafter, as shown in Fig. 2b, the screws 107 and 109 may be inserted or screwed into the washers. Fig. 2c shows the resulting assembly. Alternatively, the

screws 107, 109 may be inserted/screwed into the washers 105, 107 and then the washers 103 and 105 may be pressed/located in to respective recess 113, 117 of the respective flat member 111 , 115.

Figs. 3a to 3b show utilization of the grounding screw arrangement of Fig. 1. As shown in Fig. 3a, the grounding screw support 101 may be secured by a securing screw 301 fixing the securing strap 123 to a casing 303. Alternatively, a snap securing the grounding screw support 101 which may be integrated with the chassis, i.e. the casing 303 may be provided. The casing 303 may be provided with a machined surface element 305 of the casing 303 for receiving the screws 107 and 109. The surface element 305 may be integral with the casing 303 or form a plate which is attached to the casing. As shown in Figs. 3b and 3c, the cable lug 129 may be secured with the screws 107, 109 to the anti-drop assembly 305. The surface element 305 is the electrical contact surface for the lug 129.

Fig. 4 shows a screw support 401 which comprises a first flat member 403 having a first recess 405, and a second flat member 407 having a second recess 409. The flat members 403 and 407 are flexibly joined by a joining member 411 , which may be U-shaped and formed to hold captive screws which are not depicted in Fig. 4. Optionally, the screw support 401 may comprise a securing strap 413 outwardly extending from e.g. the first flat member 403. At its end, the securing strap 413 comprises a flat member 415 with a recess 417 for receiving e.g. a securing screw.

The flat members 403 and 407 may respectively be provided with radially

extending cuts 419 defining a plurality of resilient members 421 for preventing slipping out of the first screw or of the second screw.

The screw support 401 provides solution with captive screws which may be pressed in and hold by a thin stainless flexible sheet metal part forming, e.g. a spring steel screw support 401. Main function is to hold the screws together and allow individual screwing/-un-screwing. A flexible long enough spring steel strap could fulfill this at the same time as it is un-compressible between screw head and grounding lug. According to some implementations, also metal washers, e.g. not threaded, may be pressed on the screws. Furthermore, the shape of the rubber or metal strap forming a screw support can be made different. Furthermore, more than two screws, e.g. 4 screws, may be used. The screw support 101 , 401 enables retaining two or more screws in one common part. Furthermore, screws may be screwed in and out individually. According to some implementation forms, the screws may be secured from being dropped during the installation and handling by the screw support 101 , 401. According to some implementation forms, a friction between the respective screw head and the respective washer 119, 121 doesn't twist or rotate the screw support 101 being formed by e.g. a rubber strap.

According to some implementation forms, both grounding screws 107 and 109 may be kept upon the basis of a flexible silicon rubber strap, i.e. the screw support 101 with holes or recesses 113, 115 for two metal, e.g. stainless, washers 103, 105. The washer' outside may have a 360deg groove 119, 121. The metal washers 103, 105 may be mounted into the silicon strap 101 and fixed by the rubber around the groove 119, 121. The hole 113, 115 in the rubber shall allow the respective washer 103, 105 to rotate without also rotating or twisting the rubber strap. When the screw 107, 109 is tightened friction between screw head and washer may make the washer rotate with the screw 107, 109.

According to some implementation forms, both washers 103, 105 can be kept together in one common joining part, wherein the screws may be screwed and unscrewed individually. Further, the strap 123 can be attached to the chassis 303 with a separate screw or a "rubber-strap-in- keyhole" solution.

According to some implementation forms, the ground screws 107, 109 may be screwed through the respective washer 103, 105. Since the screws 107, 109 may have shoulders making the screws 107, 109 to be captive, the screws 107, 109 may be kept by the washers 103, 105 also when the screws 107, 109 are removed from the chassis 303.

Claims

CLAIMS:

1. A screw support for securing a plurality of screws, the screw support comprising: a first flat member (111 ) with a first recess (113) for accommodating a first screw, the first recess (113) being formed to prevent slipping out of the first screw upon insertion; a second flat member (115) with a second recess (117) for accommodating a second screw, the second recess being formed to prevent slipping out of the second screw upon insertion; and a joining member (118) for flexibly joining the first flat member (111 ) with the second flat member (115).

2. The screw support of claim 1 , further comprising a first washer (103) being rotatably arranged in the first recess (113), and a second washer (105) being rotatably arranged in the second recess (117), the first washer (103) being formed for accommodating the first screw, the second washer (105) being formed for accommodating the second screw.

3. The screw support of claim 2, wherein the first washer (103) and the second washer (105) respectively comprise a circular groove (119, 121 ) being formed in the respective outside wall of the respective first and second washer (103, 105), and wherein the first recess (113) and the second recess (115) respectively comprise a circular elevation respectively engaging in the respective circular groove (119, 121 ).

4. The screw support of claim 2 or 3, wherein the washer (103, 105) have an inside thread, and wherein the screws are screwed or inserted into the washers

(103, 105).

5. The screw support of claim 2 or 3 or 4, wherein the flat members (111 , 115) hold the washer (103, 105), and wherein the washer (103, 105) are adapted for holding the screws.

6. The screw support of claim 1 , wherein the first flat member (403, 407) and the second flat member respectively comprise radially extending cuts (419) defining a plurality of resilient members (421) for preventing slipping out of the first screw or of the second screw.

7. The screw support of any of the preceding claims, wherein the joining member (118) is U-formed, and wherein a distance between the respective end of the joining member (118) and the top of the joining member (118) is greater than or equal to a distance between centers of the first and the second recess (113, 115).

8. The screw support of any of the preceding claims, wherein the joining member (118) is U-formed, and wherein the first flat member (111 ) and the second flat member (115) are arranged at the respective end of the joining member (118).

9. The screw support of any of the preceding claims, wherein the first flat member (111 ), the second flat member (115) and the joining member (118) are integrally formed.

10. The screw support of any of the preceding claims, further comprising a securing strap (123) extending from the first flat member (111 ) or from the second flat member (115), the securing strap (123) comprising a recess (127) for receiving a securing screw.

11. The screw support of any of the preceding claims, wherein the first flat member (111 ), the second flat member (115) and the joining member (118) are made of an elastic material, in particular of silicone, rubber, plastic or spring steel.

12. A grounding screw arrangement, comprising: the screw support of any of the claims 1 to 10; a first grounding screw (107) being hold in the first recess (113) of the first flat member (111 ); and a second grounding screw (109) being hold in the second recess (117) of the second flat member (115).

13. An electric arrangement, comprising: a casing (303) for an electric component; and a grounding cable (131 ) comprising a cable lug (129), the cable being (129) connected to the casing (303) by the grounding screw arrangement of claim 10.