阅读说明：本技术 天线安装装置 (Antenna mounting device ) 是由 刘茂生 苏瑞鑫 刘朝辉 唐普亮 于 2019-04-08 设计创作，主要内容包括：本发明涉及一种天线安装装置,所述天线安装装置构造成用于将多个基站天线共同地安装在同一根抱杆上,所述天线安装装置包括：支架(1),所述支架在安装状态下限定中央凹部(4),所述中央凹部构造成,使得所述中央凹部(4)松动地接纳抱杆(3)；紧固装置(2),所述紧固装置构造成用于将所述支架(1)紧固在抱杆(3)上；和多个连接构件(5),每个连接构件构造成用于与所述多个基站天线(6)之中的至少一个基站天线连接,各连接构件在支架上具有预定的相对位置。通过所述天线安装装置,多个基站天线能以较精确的彼此相对位置安装在同一根抱杆上。(The present invention relates to an antenna mounting device configured to mount a plurality of base station antennas on the same mast in common, the antenna mounting device including: a bracket (1) which in the mounted state defines a central recess (4) which is configured such that the central recess (4) loosely receives a pole (3); -a fastening device (2) configured for fastening the bracket (1) on a pole (3); and a plurality of connection members (5), each configured for connection with at least one base station antenna among the plurality of base station antennas (6), each connection member having a predetermined relative position on the support. Through antenna installation device, a plurality of base station antennas can be installed on same holding pole with relative position each other more accurately.)

1. An antenna mounting apparatus configured for mounting a plurality of base station antennas collectively on the same mast, the antenna mounting apparatus comprising:

a bracket (1) which in the mounted state defines a central recess (4) which is configured such that the central recess (4) loosely receives a pole (3);

-a fastening device (2) configured for fastening the bracket (1) on a pole (3); and

a plurality of connection members (5), each configured for connection with at least one base station antenna among the plurality of base station antennas (6), each connection member having a predetermined relative position on the support.

2. The antenna mounting arrangement according to claim 1, characterized in that the bracket (1) comprises a bracket plate;

preferably, the carrier (1) comprises an upper carrier plate (11) and a lower carrier plate (12), each having a central recess, the central recesses of the carrier plates jointly defining the central recess (4) of the carrier;

preferably, the upper bracket plate (11) and the lower bracket plate (12) are one integrally connected component or two separate components;

preferably, the central recesses of the upper support plate (11) and of the lower support plate (12) each have a lateral opening, which is configured to be accessible by a holding pole (3).

3. The antenna mounting arrangement according to claim 1 or 2, characterized in that the carrier (1) comprises a plurality of carrier plates (14, 15) which are directly or indirectly connected to each other in circumferential direction.

4. An antenna mounting arrangement according to any of claims 1-3, characterized in that each connecting member (5) is fixed as a separate part to the bracket;

preferably, the support (1) has a plurality of prefabricated holes, each connecting element (5) being fastened to the support (1) by means of a fastening element (7) which passes through one of the holes in each case;

preferably, the single connecting element (5) is configured as a U-shaped part having one bottom edge (5a) and two side edges (5b, 5 c);

preferably, the U-shaped part has a connecting element (5d) projecting from the bottom edge (5a) in a direction away from the two side edges (5b, 5c) for connection to the at least one base station antenna.

5. The antenna mounting arrangement according to any of claims 1-4, characterized in that the fastening arrangement (2) comprises a plurality of separate fastening components (20);

preferably, the single fastening assembly (20) comprises an engaging element (21) and a pressing element (22) configured for pressing the engaging element (21) against the holding pole (3);

preferably, the engagement element (21) is configured as a U-shaped part having a base (21a) and two side edges (21b, 21c), each side edge having an engagement section (21e) for engagement with the holding pole (3), the pressing element (22) being capable of acting on the base (21 a);

preferably, the engaging element (21) has a guiding element (21d) configured for guiding the engaging element (21) during movement of the engaging element (21);

preferably, the pressing element (22) is a screw;

preferably, the engagement element (21) has a recess (26) for receiving a free end of the screw.

6. An antenna mounting arrangement according to any of claims 1 to 5, characterized in that the fastening arrangement (2) comprises a plurality of separate fastening assemblies (20), a single fastening assembly (20) constituting a structural unit with a single connecting member;

preferably, the fastening assembly (20) is captively received between two side edges (5b, 5c) of the connecting member (5);

preferably, the fastening assembly (20) comprises a joining element (21) and a pressing element (22), the pressing element being configured for pressing the joining element (21) against the holding pole (3), the joining element (21) being configured as a second U-shaped part having one base (21a) and two side edges (21b, 21c), each side edge of the joining element (21) having a joining section (21e) for joining with the holding pole (3), the pressing element (22) being capable of acting on the base (21a) of the joining element (21);

preferably, the engaging element (21) has a guide element (21d), the connecting member (5) has a corresponding guide element (24), the guide element (21d) and the corresponding guide element (24) co-act for guiding the engaging element (21) during movement of the engaging element (21);

preferably, said guide elements (21d) are a plurality of finger-shaped elements parallel to each other and said corresponding guide elements (24) are a plurality of holes;

preferably, the pressing element (22) is a screw, the connecting member (5) having a threaded hole (25), the screw being received in the threaded hole (25).

7. An antenna mounting arrangement according to any one of claims 1 to 6, wherein the antenna mounting arrangement is configured for mounting three, four or more base station antennas collectively on the same mast.

8. An antenna mounting apparatus configured for mounting a plurality of base station antennas collectively on a mast, the antenna mounting apparatus comprising:

a bracket (1) defining a central recess (4) configured for loosely receiving a pole (3);

a fastening device (2) connected to the bracket and configured for fastening the bracket (1) on a pole (3) in the central recess; and

a plurality of connection members (5), each configured for connection with at least one base station antenna among the plurality of base station antennas (6), each connection member being mounted to a support;

wherein the fastening arrangement comprises at least one fastening component (20) mounted to one of the connecting members respectively such that the position of the at least one fastening component (20) is adjustable relative to the corresponding connecting member, the adjustment of the position of the at least one fastening component (20) causing the fastening arrangement to engage and fasten the antenna mounting arrangement to the pole.

9. An antenna mounting arrangement according to claim 8, characterised in that each attachment member (5) includes a fastening assembly (20) mounted thereto, each fastening assembly being mounted to the respective attachment member such that the position of each fastening assembly (20) is adjustable relative to the respective attachment member (5) so that each fastening assembly can engage with a pole.

10. An antenna mounting arrangement according to claim 8 or 9, characterized in that the at least one fastening component (20) and the respective connecting member (5) are configured such that the at least one fastening component is movable relative to the respective connecting member in a direction towards and away from the pole.

Technical Field

The present invention relates generally to the field of base station antennas, and more particularly to an antenna mounting arrangement configured for mounting a plurality of base station antennas collectively on the same mast.

Background

In a mobile communication network, it is necessary to configure base station antennas appropriately according to actual conditions such as coverage requirements of the network, traffic distribution, interference resistance requirements, and the like. In some application scenarios, three or more base station antennas need to be mounted on the pole around the same pole of a communication tower.

Fig. 1 depicts a prior art antenna mounting device comprising two half rings R1, R2 which jointly enclose a pole (e.g. a single pole) and are fixed to each other at their ends such that they firmly clamp and are thereby fixed to the pole. A plurality of connecting elements C1, C2, C3 can be fixed on the two half-rings R1, R2, each connecting element being configured for connection with a base station antenna. In order to ensure the clamping of the two half rings on the pole, the two half rings have a gap S at their ends. During the installation process, it is difficult to ensure the uniformity of the two gaps S. Due to the non-uniformity of the two gaps S and due to the deformation of the two half rings R1, R2 during clamping, the actual position of the respective connecting elements C1, C2, C3 relative to one another often deviates from the predetermined ideal relative position, and therefore there is an undesired deviation of the actual position of the respective base station antennas relative to one another from the predetermined ideal relative position.

Disclosure of Invention

The present invention is directed to an antenna mounting device for mounting a plurality of base station antennas on the same mast in common, with which a more precise relative position of the plurality of base station antennas can be achieved.

In accordance with one aspect of the present invention, the object is achieved by an antenna mounting apparatus configured for mounting a plurality of base station antennas commonly on the same mast, comprising:

a bracket defining a central recess in an installed condition, the central recess configured such that the central recess loosely receives a clasping rod;

a fastening device configured to fasten the bracket to a pole; and

a plurality of connection members, each connection member configured for connection with at least one base station antenna among the plurality of base station antennas, each connection member having a predetermined relative position on the support.

According to another aspect of the present invention, there is provided an antenna mounting apparatus configured to mount a plurality of base station antennas collectively on a mast, the antenna mounting apparatus comprising:

a bracket defining a central recess configured for loosely receiving a clasping rod;

a fastening device connected to the bracket and configured to fasten the bracket to the pole within the central recess; and

a plurality of connection members, each connection member configured for connection with at least one base station antenna among the plurality of base station antennas, each connection member mounted to a bracket;

wherein the fastening arrangement comprises at least one fastening component, the at least one fastening component being mounted to one of the connecting members respectively such that the position of the at least one fastening component is adjustable relative to the corresponding connecting member, the adjustment of the position of the at least one fastening component causing the fastening arrangement to engage with and fasten the antenna mounting arrangement with the pole.

In some embodiments, the bracket may include a bracket plate.

In some embodiments, the carrier may include an upper carrier plate and a lower carrier plate, each carrier plate may have a central recess, respectively, the central recesses of the carrier plates collectively defining the central recess of the carrier.

In some embodiments, the upper and lower brace plates may be one integrally connected component or two separate components.

In some embodiments, the central recesses of the upper and lower mounting plates may each have a side opening, which may be configured to be passed by a pole.

In some embodiments, the bracket may include a plurality of bracket plates, which may be directly or indirectly connected to each other in a circumferential direction.

In some embodiments, each connecting member may be secured to the bracket as a separate component.

In some embodiments, the bracket may have a plurality of preformed holes, and each connecting member may be secured to the bracket by a fastening element passing through one of the holes.

In some embodiments, a single connecting member may be configured as a U-shaped component having a bottom edge and two side edges.

In some embodiments, the U-shaped member may have a connecting element extending from the bottom side in a direction away from the two side edges for connection with the at least one base station antenna.

In some embodiments, the fastening device may comprise a plurality of individual fastening components.

In some embodiments, the fastening device may be constructed similarly to the two half-rings shown in fig. 1, wherein the bracket is connected to both half-rings.

In some embodiments, a single fastening assembly may include an engaging element and a pressing element configured to press the engaging element against the clasping rod.

In some embodiments, the engagement element may be configured as a U-shaped member having a bottom edge and two side edges.

In some embodiments, each side edge may have an engagement section for engaging with a pole.

In some embodiments, the pressing element can act on the base edge.

In some embodiments, the engaging element may have a guiding element configured for guiding the engaging element during movement thereof.

In some embodiments, the pressing element may be a screw.

In some embodiments, the engagement element may have a recess for receiving a free end of the screw.

In some embodiments, the fastening device may comprise a plurality of individual fastening components, and an individual fastening component and an individual connecting member may constitute a structural unit.

In some embodiments, the fastening assembly may be non-captively received between the two sides of the connecting member.

In some embodiments, the fastening assembly may comprise an engaging element configured for pressing the engaging element against the holding pole, and a pressing element configured for pressing the engaging element against the holding pole, the engaging element may be configured as a second U-shaped part having one base and two side edges, each side edge of the engaging element having an engaging section for engaging with the holding pole, the pressing element being able to act on the base edge of the engaging element.

In some embodiments, the engaging element may have a guiding element, and the connecting member may have a corresponding guiding element, which guiding element and the corresponding guiding element may co-act for guiding the engaging element during movement thereof.

In some embodiments, the guide element may be a plurality of finger elements parallel to each other, and the corresponding guide element may be a plurality of holes.

In some embodiments, the pressing element may be a screw, and the connecting member may have a threaded hole in which the screw may be received.

In some embodiments, the antenna mounting arrangement may be configured for mounting three, four or more base station antennas collectively on the same mast.

In some embodiments, each attachment member may comprise a fastener assembly mounted to the attachment member, each fastener assembly being mounted to a respective attachment member such that the position of the respective fastener assembly is adjustable relative to the respective attachment member so that each fastener assembly can engage with the pole.

In some embodiments, the at least one fastening assembly and the respective connecting member may be configured such that the at least one fastening assembly is movable relative to the respective connecting member in a direction towards and away from the pole.

The features mentioned above and those explained below can be combined with one another as desired, if appropriate technically.

Drawings

The invention is explained in more detail below with the aid of specific embodiments with reference to the drawings. The schematic drawings are briefly described as follows:

fig. 1 is a schematic top view of an antenna mounting arrangement for a base station antenna according to the prior art;

fig. 2 is a schematic plan view of an antenna mounting device according to an embodiment of the present invention in a mounted state;

fig. 3A to 3D are schematic perspective views for describing the mounting process of the antenna mounting device according to fig. 2;

fig. 4A is a schematic perspective view of a structural unit of the antenna mounting device, which is composed of a single connecting member and a single fastening assembly;

FIG. 4B is an exploded view of the structural unit according to FIG. 4A;

FIG. 4C is a longitudinal section through the structural unit according to FIG. 4A;

fig. 5 is a schematic perspective view of a mounting plate of an antenna mounting device according to a further embodiment;

fig. 6 is a schematic perspective view of a mounting plate of an antenna mounting device according to a further embodiment;

fig. 7 is a schematic top view of an antenna mounting device according to a further embodiment in a mounted state; and is

Fig. 8 is a schematic perspective view of a base station antenna system according to an embodiment of the present invention.

Detailed Description

Fig. 2 is a schematic plan view of the antenna mounting device 10 according to the embodiment of the invention in a mounted state, and fig. 3A to 3D are schematic perspective views for describing a mounting process of the antenna mounting device according to fig. 2.

As shown in fig. 2, the antenna mounting device 10 is configured to mount three base station antennas 6 on the same mast 3 in common. The base station antennas 6 are only schematically represented. The antenna mounting arrangement comprises a bracket 1 defining a central recess 4 which loosely receives a pole 3. In other words, the central recess 4 has a dimension which is greater than the dimension of the pole 3, so that the support 1 can move relative to the pole 3 to a limited extent in the radial direction of the pole. The pole 3 is generally circular in cross-section.

In the embodiment shown in fig. 2 and 3A to 3D, the carrier 1 comprises an upper carrier plate 11 and a lower carrier plate 12, each having a central recess 4a, 4b, respectively, which jointly define the central recess 4 of the carrier. The central recesses 4a, 4b each have a lateral opening 4c, 4d, which is configured to be able to be passed through by the holding pole 3. The carrier plates 11 and 12 can be formed in the same manner. The plurality of connecting members 5 are fixedly connected with the holder plates 11, 12 between the holder plates 11, 12. The carrier plates 11, 12 and the connecting elements 5 can each have a plurality of prefabricated holes which receive corresponding fastening elements 7 for the fixed connection of the respective connecting element 5 to the carrier plates 11, 12. The side openings 4c, 4d can be closed by one of the connecting members 5. The position of the connecting elements 5 relative to one another on the carrier 1 can be predetermined relatively precisely by means of prefabricated holes in the carrier.

The mounting process of the antenna mounting device according to fig. 2 is explained below with reference to fig. 3A to 3D.

First, as shown in fig. 3A, the bracket plates 11, 12 and the two connecting members 5 may be preassembled into one pre-assembled unit 1a having a side opening defined by the side openings 4c, 4d of the bracket plates 11, 12. Then, as shown in fig. 3B, the preassembled unit 1a is inserted through its lateral opening onto the pole 3 until the pole 3 is located in the central recess 4 of the preassembled unit 1 a. Then, as shown in fig. 3C, a further connecting member 5 is connected to the pre-assembled unit, wherein the connecting member 5 closes the lateral opening of the pre-assembled unit 1 a. Finally, the fastening device 2 is tightened so that the bracket 1 is firmly fixed to the pole 3.

Next, some embodiments of the connecting member 5 and the fastening device 2 are described with reference to fig. 4A to 4C. Fig. 4A is a schematic perspective view of a structural unit of the antenna mounting arrangement, which is formed by a single connecting element 5 and a single fastening arrangement 20, fig. 4B is an exploded view of the structural unit according to fig. 4A, and fig. 4C is a longitudinal section of the structural unit according to fig. 4A.

The individual connecting elements 5 can be designed as U-shaped parts having a base 5a and two lateral edges 5b, 5 c. The two lateral edges 5b, 5c may each have two preformed holes for receiving the fastening elements 7. The U-shaped part may have a connection element 5d projecting from said bottom edge 5a in a direction away from said two side edges 5b, 5c for connection to a base station antenna.

The connecting member 5 may be configured as a receiving and guiding means for the fastening assembly 20. The fastening assembly 20 may be received in the connecting member 5, more specifically, between the two side edges 5b, 5c of the connecting member 5.

The fastening assembly 20 may comprise an engaging element 21 and a pressing element 22 configured to press the engaging element 21 against the holding pole 3. The engaging element 21 can be configured as a U-shaped part with a base 21a and two side edges 21b, 21c, each side edge 21b, 21c can have an engaging section 21e for engaging with the holding pole 3, the pressing element 22 can act on the base 21 a. The engaging element 21 may have a guide element 21d and the connecting member 5 may have a counter-guide element 24, the guide element 21d and the counter-guide element 24 cooperating for guiding the engaging element 21 during movement of the engaging element 21. The guide elements 21d may be finger-shaped elements and the corresponding guide elements 24 may be holes. The engaging element 21 can be held non-releasably on the connecting member 5 by means of a latch 23.

In other embodiments, the guide element 21d may be a hole and the corresponding guide element 24 may be a finger element, in which case the corresponding guide element 24 may extend from the bottom edge 5a towards the engaging element 21, and the guide element 21d may be arranged in the bottom edge 21a of the engaging element 21.

The pressing element 22 may be a screw, the connecting member 5 may have a threaded hole 25, and the screw 22 may be received in the threaded hole 25. The engaging element 21 may have a recess 26 for receiving the free end of the screw 22. When screwed into the threaded hole 25, the screw 22 can be pushed towards the engaging element 21 towards the pole 3, so that the engaging element 21 presses against the pole 3. When the screw 22 is unscrewed in the threaded hole 25, the engaging element 21 is released, so that the engaging element 21 can be loosened with respect to the pole 3. In addition, a locknut 27 may be provided for preventing the screw 22 from being unintentionally loosened in the fastened state.

In the embodiment shown, the connecting member 5 and the fastening assembly 20 jointly form a structural unit. However, it is also contemplated that the connecting member 5 and the fastening assembly 20 may be constructed as separate units, for example, they may be installed in the bracket 1 adjacent to each other in the circumferential direction of the bracket 1.

In principle, three fastening assemblies 20 enable the fastening of the support 1 to the holding pole 3. When the number of the connection members 5 is more than three, at least one of the connection members 5 may not be provided with the fastening assembly 20.

In the embodiment shown, the connecting member 5 is a separate component from the bracket 1 and is interconnected by means of fastening elements 7. However, it is also contemplated that the connecting member 5 may be an integral part of the holder 1; or the connecting member 5 and the bracket 1 are separate parts and then formed as an integral part by welding.

Fig. 5 is a schematic perspective view of a mounting plate of an antenna mounting device according to a further embodiment. Fig. 5 shows only the two carrier plates 11, 12 of the antenna installation device, wherein the other components of the antenna installation device can be designed identically to or differently from the embodiment of fig. 2. The upper carrier plate 11 and the lower carrier plate 12 may be of similar design, and in the mounted state of the antenna mounting device, the upper carrier plate 11 may be twisted, for example by 120 °, relative to the lower carrier plate 12.

Fig. 6 is a schematic perspective view of a mounting plate of an antenna mounting device according to a further embodiment. Fig. 6 shows only the two carrier plates 11, 12 of the antenna assembly, which are connected to one another by a connecting plate 13 in one piece, wherein the other components of the antenna assembly can be of the same design as in the embodiment of fig. 2 or of a different design. The bracket plates 11, 12 and the connecting plate 13 may be pressed from one metal plate.

Fig. 7 is a schematic plan view of the antenna mounting device 10 according to the embodiment in a mounted state. The antenna mounting device is configured for mounting four not shown base station antennas jointly on the same mast 3. The antenna mounting device comprises a bracket 1, which in the mounted state defines a central recess 4, which central recess 4 loosely receives the pole 3, such that the bracket 1 can move relative to the pole 3 to a limited extent in the radial direction of the pole when the fastening device 2 is released.

In the embodiment shown in fig. 7, the antenna mounting device has four connecting members 5 and four fastening components 20, which fastening components 20 together form the fastening device 2. These connecting members 5 have an angular spacing of 90 ° on the carrier 1.

In the embodiment shown in fig. 7, the carrier 1 has two carrier plates 14, 15 on both sides of the mast 3, wherein the two carrier plates 14 on one side of the mast 3, i.e. an upper carrier plate and a lower carrier plate (not visible in fig. 7), can be formed as two separate parts or as a part which is connected in one piece; and the two carrier plates 15 on the other side of the mast 3, an upper carrier plate and a lower carrier plate (not visible in fig. 7), can also be formed as two separate parts or as one part which is connected in one piece. The holder plate 14 and the holder plate 15 may be indirectly connected at both ends thereof via the connecting member 5. In some embodiments, not shown, the carrier plate 14 and the carrier plate 15 may also be directly connected at their two ends. Each connecting element 5 can be mounted between two upper carrier plates 14, 15 and two lower carrier plates 14, 15. The carrier plates 14, 15 and the connecting elements 5 can each have a plurality of prefabricated holes which receive corresponding fastening elements 7 for the fixed connection of the respective connecting element 5 to the carrier plates 14, 15. The position of the connecting elements 5 relative to one another on the carrier 1 can be predetermined relatively precisely by means of prefabricated holes in the carrier plate. In the embodiment shown in fig. 7, the connecting element 5 and the fastening device 2 can be constructed identically, similarly or differently to the embodiment according to fig. 2.

In the embodiment shown, a single connection member 5 is configured for connecting one base station antenna. However, it is also conceivable that a single connecting member 5 may be configured for connecting a plurality of base station antennas, for example small base station antennas (smallcell). In the case where the base station antenna has a large height, two or more antenna mounting devices may be provided in sequence on the pole in the height direction of the pole, and each base station antenna may be fixed to the pole by one connecting member of each antenna mounting device.

Fig. 8 is a schematic perspective view of a base station antenna system in which a plurality of base station antennas 6 are mounted on a mast 3 by means of an upper and a lower antenna mounting device 10. These antenna mounting devices may be constructed in accordance with the foregoing embodiments.

Compared with the antenna mounting device in the prior art, the antenna mounting device can be easily and firmly mounted on the holding pole, and the accurate relative position of the base station antennas to each other can be ensured. In addition, the relative position of the antenna mounting means with respect to the pole can be easily fine-tuned by means of the adjustable fastening means.

In this application, the terms "upper", "lower" and "side" are defined with reference to a pole that is vertically oriented. The pole may also be oriented obliquely or horizontally, wherein the terms are to be understood in a relative sense.

It is noted that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that the terms "comprises" and "comprising," and other similar terms, when used in this specification, specify the presence of stated operations, elements, and/or components, but do not preclude the presence or addition of one or more other operations, elements, components, and/or groups thereof. The term "and/or" as used herein includes all arbitrary combinations of one or more of the associated listed items. In the description of the drawings, like reference numerals refer to like elements throughout.

The thickness of elements in the figures may be exaggerated for clarity. It will be further understood that if an element is referred to as being "on," "coupled to" or "connected to" another element, it can be directly on, coupled or connected to the other element or intervening elements may be present. Conversely, if the expressions "directly on … …", "directly coupled with … …", and "directly connected with … …" are used herein, then there are no intervening elements present. Other words used to describe the relationship between elements, such as "between … …" and "directly between … …", "attached" and "directly attached", "adjacent" and "directly adjacent", etc., should be similarly interpreted.

Terms such as "top," "bottom," "above," "below," "over," "under," and the like, may be used herein to describe one element, layer or region's relationship to another element, layer or region as illustrated in the figures. It will be understood that these terms are intended to encompass other orientations of the device in addition to the orientation depicted in the figures.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the present inventive concept.

It is also contemplated that all of the exemplary embodiments disclosed herein may be combined with each other as desired.

Finally, it is pointed out that the above-described embodiments are only intended to be understood as an example of the invention and do not limit the scope of protection of the invention. It will be apparent to those skilled in the art that modifications may be made in the foregoing embodiments without departing from the scope of the invention.