Abstract:
To mount articles onto two or more surfaces can be difficult if the relative position of the surfaces can vary due to for example manufacturing tolerances. This can cause high levels of residual stress in the mounting arrangement that especially in a high vibration environment can cause failures. Conventional mounting arrangements overcame this by complex or heavy designs, or by the use of methods such as shimming. This generally caused conventional designs to be expensive and cumbersome to fit. The disclosed arrangement comprises a simple and relatively inexpensive bracket and adjustable member, wherein the adjustable member can be adjusted to compensate for misalignment. After the bracket is fitted into position, the adjustable member can be positioned relatively to the bracket in such a manner that the bracket is fully supported by the adjustable member without any unwanted residual stress.

Description:
TECHNICAL FIELD  
       [0001]     This disclosure relates to a mounting bracket arrangement and more particularly to an adjustable mounting bracket for mounting articles to two or more offset surfaces.  
       BACKGROUND  
       [0002]     Internal combustion engines may carry a number of externally mounted accessories such as air-conditioning compressors, power steering pumps and alternators. These may be belt, gear or chain driven devices and carry therefore restrictions in positioning with regards to alignment. A common arrangement is to have several or even all pulleys driven by, and therefore aligned with, the driving crankshaft pulley. To mount accessories to an engine with regards to the above weight of the accessories, forces acting upon the accessories, maximum load carrying capacity of engine components, limited number of mounting points available on the engine and vibration caused by the engine and the accessories should be considered.  
         [0003]     In one example, an engine for a passenger bus is required to be fitted with an alternator, a steering pump, a vacuum pump and in addition, two air-conditioning compressors. The bus frequently operates in hot conditions, therefore requiring separate air-conditioning systems for both the passenger compartment and the driver&#39;s area. Air-conditioning compressors place strenuous design requirements on mounting arrangements, due to size, weight and frequent shock loads from the engaging and disengaging clutches.  
         [0004]     From the above, it follows that the bracket will likely have to be mounted to the engine by means of multiple mounting locations, especially since all loads are transverse to the longitudinal axis of the mounting locations and thus may induce torsional movement or high resulting forces. Engines tend not to have large surfaces in one plane, and consequently the mounting locations tend not be in the same plane or on a single component. Manufacturing and assembly tolerances introduce varying degrees of misalignment between several components and especially between the cylinder block and the cylinder head. If the tolerances are such that one or more mounting locations of the bracket is in contact with a surface on the engine only after tightening of a fastener, unwanted stress may be present in the bracket, which can lead to premature failure of the bracket.  
         [0005]     In the past, this uneven bracket loading has been overcome by either complex or strengthened brackets, or an adjustment method such as shimming. This is not desirable, as a complex or strengthened bracket increases weight, size and cost of the bracket. Shimming has disadvantages in that it tends to be time consuming during assembly and shims can be awkward to fit.  
         [0006]     The present disclosure is directed at overcoming one or more of the above identified issues.  
       SUMMARY OF THE DISCLOSURE  
       [0007]     According to one aspect of the present disclosure, there is provided a mounting bracket arrangement having a first surface lying substantially in a first plane, a second surface lying substantially in a second plane and a mounting bracket having a portion contacting the first surface. The bracket further has a passage extending therethrough adjacent the second surface. An adjustment member is positioned in the passage and has an end surface contacting the second surface and is adjustable along an axis. The bracket is adapted to support a load transverse to the axis.  
         [0008]     According to another aspect of the present disclosure, there is provided a method for mounting an article to a first surface lying substantially in a first plane and a second surface lying substantially in a second plane. The method comprises: positioning a mounting bracket adjacent to the first and second surfaces, causing a portion of the mounting bracket to contact the first surface, engaging an adjustment member in a passage extending through the bracket adjacent to the second surface and adjusting the position of the adjustment member along an axis until an end surface of the adjustment member contacts the second surface. The bracket is adapted to support a load transverse to the axis.  
         [0009]     Other features and aspects of this disclosure will be apparent from a reading of the following description and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a front view of an internal combustion engine showing the mounting bracket arrangement, carrying an assortment of accessories.  
         [0011]      FIG. 2  is a diagrammatic cross-sectional view of a portion of the mounting bracket arrangement.  
         [0012]      FIG. 3  is a fragmentary view of a portion of the mounting bracket arrangement shown in  FIG. 2 , showing an alternative fastening arrangement.  
         [0013]      FIG. 4  is an end view of a tubular member from part of the mounting bracket arrangement having internal portions for tool engagement.  
         [0014]      FIG. 5  is a fragmentary view of a portion of the mounting bracket arrangement shown in  FIG. 2 , showing another alternative fastening arrangement.  
     
    
     DETAILED DESCRIPTION  
       [0015]     With reference to  FIG. 1 ., a first mounting bracket  10  and a second mounting bracket  12  in accordance with this disclosure are fitted to an internal combustion engine  14 . Engine  14  comprises a cylinder block  15  and cylinder heads  16  and  17 . Brackets  10  and  12  secure air-conditioning compressors  18  and  19 , a vacuum pump  20 , an alternator  22  and a steering pump  24  to engine  14 . Other types of articles may also be mounted and need not be belt, chain or gear driven. A crankshaft pulley  26  is the driving pulley and drives the aforementioned accessories in addition to a coolant pump  28  via a drive belt  30 . In addition to the accessories, the brackets carry idler pulleys  32  and  34  and a belt tensioner  36 . Coolant pump  28  is fitted directly onto the engine. First mounting bracket  10  and second mounting bracket  12  have substantially the same function and both share the same principle. For simplicity only mounting bracket  10  will be discussed further.  
         [0016]     With reference to  FIG. 2 , mounting bracket  10  comprises a first projection  40  and a second projection  42 , projection  42  extending further from surface  11  of bracket  10  than projection  40 . For simplicity only one of each projections  40  and  42  are shown, but a plurality of substantially similar projections may be employed. A surface  43  of projection  42  is shown in direct contact with a surface  44  of cylinder block  15 , however another object such as a washer or a bracket (not shown) can be fitted in between surface  43  and surface  44 . Projection  42  is shown with a longitudinal passage  45  adapted to receive a fastener such as bolt  46 . Bolt  46  has a threaded portion  47  that engages with a threaded hole  48  in cylinder block  15  to secure bracket  10  to cylinder block  15 . Projection  40  comprises a surface  54  adjacent to, but not in contact with, a surface  56  of cylinder head  17 . The length of projection  40  is such that even in case of tolerance extremes surface  54  does not contact surface  56 . Projection  40  further comprises a threaded longitudinal passage  50  adapted to receive an externally threaded tubular member, such as sleeve  52 . Sleeve  52  has a longitudinal passage  58  adapted to receive a fastener such as bolt  60 . It further comprises an engagement portion such as external portion  61  or internal portion  63  as shown in  FIG. 4 , for manual or tool engagement, and an end surface  53  that is in contact with surface  56  of cylinder head  17 . End surface  53  is shown in direct contact with surface  56 , however another object such as a washer or a bracket (not shown) can be fitted in between end surface  53  and surface  56 . Bolt  60  has a threaded portion  62  that engages with a threaded hole  64  in cylinder block  17  to secure sleeve  52  to cylinder block  16 .  
         [0017]     Assembly of the bracket mounting arrangement is as follows. Cylinder heads  16  and  17  and cylinder block  15  are pre-assembled as part of engine  14 . Mounting bracket  10  is positioned adjacent to cylinder block  15  and cylinder head  17 . Surface  43  of projection  42  and surface  44  of block  15  are positioned such that surface  43  and surface  44  make contact and that fastener  46  can be fitted through passage  45  and threaded into hole  48 . If preferred an adhesive such as Loctite 243 or a locking washer or similar can be applied, but at his stage fastener  46  will not be given its required torque to ease the alignment of fastener  60  and hole  64  in cylinder head  17 . Once fastener  60  and hole  64  are aligned and partially engaged, fastener  46  will be given its substantially correct torque. As with fastener  46 , an adhesive such as Loctite 243, or a locking washer or similar can be applied to fastener  60 .  
         [0018]     Whilst aligning fastener  60  with hole  64 , sleeve  52  is positioned in projection  40  such that end surface  53  and cylinder head surface  56  do not make contact. Before or after fastener  46  has been given its substantially correct torque, sleeve  52  is positioned on an axis  55 , axis  55  being transverse, but not necessarily at a right angle, to the direction of the load from the accessories. Sleeve  52  is engaged further at engagement portion  61  to cause a screw like motion through projection  52 . The engagement can be manually or by use of a suitable tool such as a spanner. After end surface  53  makes contact with surface  56 , a torque is applied to pre-load the connection between projection  40  and sleeve  52  to reduce relative movement of the threaded surfaces of projection  40  and sleeve  52  during operation. If preferred, sleeve  61  can be secured in projection  40  by use of an adhesive such as Loctite 243 or a locknut  66  ( FIG. 3 ) threaded onto the exterior surface of sleeve  52 . After the above operation has been completed fastener  60  is tightened to the correct torque and if required fastener  46  can be retightened also.  
         [0019]     The accessories to be fitted to the bracket can be fitted before or after the bracket is mounted to the engine.  
         [0020]     One variation of the present disclosure replaces a bolt-type fastener such as fastener  46  with a stud and nut arrangement (not shown). For example, a bar (not shown) with at least one threaded portion is engaged in a preferably threaded fashion with hole  48  of cylinder block  15 . After mounting bracket  10  has been positioned on the bar, a nut is threaded onto the bar to secure mounting bracket  10 .  
         [0021]     With reference to  FIG. 5 ., a variation of the present disclosure is substantially similar, but sleeve  52  is countersunk (not shown) and adapted to take a fastener of the socket type such as an Allen screw  68 .  
         [0022]     In yet another variation of the present disclosure the tubular member is not threadingly, but slidably engaged with projection  40 . Once the tubular member is in the desired position, it can be secured to projection  40  by a welding process or an adhesive. For an alternative locking method of the slideable tubular member, the external surface of the tubular member can have partially threaded portions to accommodate locknuts at either end of the tubular member.  
         [0023]     Another embodiment of the present disclosure (not shown) is substantially similar, but not all or none of fasteners  46  and  60  extend through projections  40  and  42 . In this case projections  40  and  42 , and the tubular member previously designated as sleeve  52  do not need to have longitudinal passages. The fasteners previously designated  46  and  60  will then be acting upon other parts of bracket  10 . Preferably however, the fasteners still engage the surfaces  43  and  44  near the part of contact between the bracket  10  and the adjustment member  52  and respective surfaces  43  and  44 .  
       INDUSTRIAL APPLICABILITY  
       [0024]     This disclosure provides a solution for mounting components to two or more surface which are not aligned and of which their relative positions are not exactly known due to manufacturing tolerances or otherwise. The bracket arrangement, which is adjustable to overcome manufacturing tolerances found on the surfaces it will be mounted to, can be fitted without introducing unwanted residual stress in the bracket.  
         [0025]     During fitment, mounting bracket  10  is disposed adjacent the mounting surfaces, such that fixed projection  42  contacts surface  44 . Projection  40  is positioned adjacent end surface  53 , but projection  40  and end surface  53  are not in contact. Tubular member  52  is adjusted until surfaces  53  and  56  are in contact and secured in position. After applying the correct torque to prevent thread clatter between projection  40  and member  52 , fasteners  46  and  60  are tightened to the required torque.  
         [0026]     This disclosed mounting bracket arrangement is particularly useful for mounting external accessories to internal combustion engines, where belt driven accessories have to be lined up with a crankshaft pulley. As this requires all pulleys to be in substantially the same plane, a bracket has to be in place to provide a plurality of fixing points, and to distribute the forces generated by the weight and operation of the accessories over the engine. To distribute the forces over the engine, the bracket is likely to be fitted to multiple mounting points located on both the cylinder block and the cylinder head. The relative positions of the cylinder block and the cylinder head can vary due to manufacturing and assembly tolerances. If a conventional non-adjustable bracket would be used, the bracket is highly likely to suffer from residual stress due the varying positions of the blocks and heads, therefore running the risk of fatigue during operation. The risk is aggravated by the high level of vibration the bracket may be exposed to during engine operation. The vibrations are caused by the engine itself and by the accessories and their subsystems.  
         [0027]     Those skilled in the art will recognize that the disclosed mounting bracket arrangement may be used in environments other than mounting accessories to an internal combustion engine  
         [0028]     Although the preferred embodiments of this disclosure have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.  
       LIST OF ELEMENTS  
       [0029]    
       
           10  Mounting bracket  
           11  Surface  
           12  Mounting bracket  
           14  Internal combustion engine  
           15  Cylinder block  
           16  Cylinder head  
           17  Cylinder head  
           18  Air-conditioning compressor  
           19  Air-conditioning compressor  
           20  Vacuum pump  
           22  Alternator  
           24  Steering pump  
           26  Crankshaft pulley  
           28  Coolant pump  
           30  Drive belt  
           32  Idler pulley  
           34  Idler pulley  
           36  Belt tensioner  
           40  First projection  
           42  Second projection  
           43  Surface  
           44  Surface  
           45  Longitudinal passage  
           46  Bolt  
           47  Threaded portion  
           48  Threaded hole  
           50  Longitudinal passage  
           52  Sleeve  
           53  End surface  
           54  Surface  
           56  Surface  
           58  Longitudinal passage  
           60  Bolt  
           61  External portion  
           62  Threaded portion  
           63  Internal portion  
           64  Threaded hole  
           66  Locknut  
           68  Allen screw