WO2003010437A1

WO2003010437A1 - An electric ceiling fan suspension shackle

Info

Publication number: WO2003010437A1
Application number: PCT/IN2001/000135
Authority: WO
Inventors: Rajan Narayan Nagre
Original assignee: Crompton Greaves Limited
Priority date: 2001-07-26
Filing date: 2001-07-26
Publication date: 2003-02-06

Abstract

An electric ceiling fan suspension shackle (1) comprising a U-shaped shackle clip (2) defining a curved portion (3) and a pair of confronting flanges (4) defining a flat portion (6) along the centre thereof. The flanges are profiled to sit over the suspension tube (7) in close contact therewith and fitted onto the suspension tube with known arrangement such as nut and bolt assembly and split pin. The suspension shackle also comprises a U-shaped resilient material insulator (18) corresponding to the curved portion of the shackle clip and adapted to be securely located therein. The suspension tube along with the fan is suspended against the insulator in a hook anchored on the ceiling.

Description

TITLE OF INVENTION

An electric ceiling fan suspension shackle.

PRIOR ART An electric ceiling fan motor is rigidly fitted at one end of a suspension tube whose other end is suspended with a suspension shackle in a hook anchored in the ceiling. A suspension shackle may comprise a single U- shaped shackle clip formed of a metallic sheet. The suspension tube is welded to the bottom portion of the U-shaped shackle clip and may be optionally provided with a split pin for added safety. Alternatively, the suspension shackle may comprise a pair of shackle clips formed of metallic sheets. The tube ends of the shackle clips are curved to sit over the suspension tube and fitted securely to the suspension tube by known arrangements such as nut and bolt assembly and split pin. The suspension tube along with the fan is suspended in the hook against a solid cylindrical resilient material insulator held between the confronting limbs of the U- shaped single shackle clip or between the pair of shackle clips using known arrangements such as nut and bolt assembly and split pin or pin and split pins or rivet and split pin. Due to welding of the suspension tube to the single shackle clip, manufacture and assembly of the suspension shackle is cumbersome, time consuming and expensive. A suspension shackle where the shackle clips are bolted to the suspension tube offers flexibility to the customer either to cut and reduce the tube length or to replace the tube by a different tube. Manufacture and assembly of the suspension shackle comprising two shackle clips is, however, cumbersome, time consuming and expensive. The insulator is ree to rotate about and move along the bolt, pin or rivet holding it. This gives rise to relative motion or movement between the shackle parts and causes the fan to start with a jerk at the beginning when switched on. This is not desirable and has been eliminated in our Indian Patent No 153997 (208/BOM/81) by providing the insulator with curved sides and adjoining straight edges. The shackle clips are also provided with matching curved ends and adjoining straight edges to abut the curved sides and straight edges of the insulator and prevent movement thereof. The insulator in Patent No 153997 is, however, held between the shackle clips using known arrangements described above. Such arrangements for holding the insulator include several components correspondingly increasing the cost and assembly time of the suspension shackle. Reliability of the suspension shackle is also reduced due to the large number of components used for holding the insulator. Functionally only a portion of the insulator is required to be in contact with the hook. But the insulator is required to be large to accommodate the bolt, rivet or pin running therethrough and also to prevent the insulator from falling off the bolt, rivet or pin which bears the entire load of the fan against the insulator. Large size of the insulator increases the material cost of the suspension shackle. Because the tube ends of the shackle clips are curved, the entire surface area of the bolt head is not in contact with the respective shackle clip. The contact between the bolt head and the corresponding shackle clip is practically line contact. Therefore, stress (load) distribution on the bolt head is non-uniform.

OBJECTS OF INVENTION An object of the invention is to provide an electnc ceiling fan suspension shackle which comprises less number of components and is simple in construction and reliable. Another object of the invention is to provide an electric ceiling fan suspension shackle which is easy to make and requires comparatively less time to make and assemble.

Another object of the invention is to provide an electric ceiling fan suspension shackle which is economical.

Another object of the invention is to provide an electric ceiling fan suspension shackle which does not give rise to jerks when the fan is switched on.

Another object of the invention is to provide an electric ceiling fan suspension shackle, in which stress distribution on the bolt head holding the shackle clips is uniform.

Another object of the invention is to provide an electric ceiling fan suspension shackle, which offers flexibility to customer to cut and reduce, the suspension tube length or to replace the tube by a different tube.

DESCRIPTION OF INVENTION

According to the invention there is provided an electric ceiling fan suspension shackle comprising a U-shaped shackle clip defining a curved portion and a pair of confronting flanges defining a flat portion along the centre thereof, the flanges being profiled to sit over the suspension tube in close contact therewith and fitted onto the suspension tube with known arrangement such as nut and bolt assembly and split pin; and a U-shaped resilient material insulator corresponding to the curved portion of the shackle clip and adapted to be securely located therein, the suspension tube along with the fan being suspended against the insulator in a hook anchored on the ceiling.

According to an embodiment of the invention, the curved portion of the shackle clip is provided with outwardly directed collars at the sides and the insulator is provided with outwardly directed projections at the sides adapted to abut the collars, the insulator being further provided with protruding arms along the outer surface adapted to be engaged in matching slots in the curved portion to securely locate the insulator in the curved portion.

According to an embodiment of the invention one of the flanges is provided with an earthing terminal.

The shackle clip may be made of mechanically strong material such as mild steel sheet.

The insulator may be made of resihent material such as rubber.

The following is a detailed description of the invention with reference to the accompanying schematic drawings, in which :

Figs 1 and 2 are front view and plan view respectively of an electric ceiling fan suspension shackle according to an embodiment of the invention fitted on a suspension tube; Fig 3 is partly sectional one side view of the suspension shackle of Fig

1;

Fig 4 is opposite side view of the suspension shackle of Fig 1;

Figs 5, 6, 7 and 8 are front view, plan view, side view and bottom view respectively of the shackle clip of the suspension shackle of Fig 1;

Figs 9 and 10 are side view and plan view, respectively of the insulator of the suspension shackle of Fig 1; and

Fig 11 is cross section at X-X in Fig 9.

Referring to Figs 1 to 11 of the accompanying drawings, the suspension shackle 1 comprises a U-shaped shackle clip 2 made of a mechanically strong material such as mild steel sheet and defining a curved portion 3 and a pair of corifronting flanges 4. The curved portion is provided with outwardly directed collars 5 at the sides (Figs 2, 6 and 8). The flanges define a flat portion 6 along the centre thereof (Figs 1,5 and 8) and are profiled to sit over the suspension tube 7 in close contact therewith. The flanges are fitted onto the suspension tube using known arrangement such as bolt 8 (bolt head marked 8A) secured through holes 9 in the flanges (Figs 5 and 7) and corresponding hole (not shown) in the suspension tube and plain washer 10, helical spring washer 11, nut 12 and lock nut 13 and split pin 14. Due to the flat portion 6 the entire surface area of the bolt head 8 A is in good contact with the respective flange. 15 is earthing terminal provided with the shackle clip in thread engagement therewith against washer 16. 17 is a hole for terminal 15 in a flange 4 (Fig 5). 18 is a resihent material insulator provided with outwardly directed projections 19 at the sides and two arms 20 along the outer surface (Figs 1, 2, 9, 10 and 11). The insulator is securely located in the curved portion by engaging the arms thereof in matching slots 21 in the curved portion (Figs 1, 3, 5 and 7). The outwardly directed projections of the insulator abut the collars of the curved portion of the shackle chp (Fig 2). The insulator may be made of resihent material such as rubber by moulding. The suspension tube along with the ceiling fan (not shown) is suspended against the insulator in a hook (not shown) anchored in the ceiling (not shown).

According to the invention the flanges of the shackle chp are fitted to the suspension tube and the fan is suspended in the hook against the insulator located in the curved portion of the shackle chp. The entire load of the fan is borne by the curved portion against me insulator. Fabrication of the single U-shaped shackle chp is easy, less time consuming and less expensive. Material requirement for the insulator is comparatively considerably less and it is easy and less time consuming to make it by moulding. The insulator is located in the curved portion by simply engaging the arms 20 thereof in the corresponding slots 21 in the curved portion.

Because the projections 19 of the insulator are abutting the collars 5 of the curved portion and arms 20 of the insulator are engaged in the slots 21 in the curved portion, the insulator does not move or rotate in the curved portion and is securely located therein. The invention eliminates conventional arrangements for holding the insulator and reduces the number of components. Because the insulator is securely held in the curved portion, there is no relative motion or movement between the component parts of the shackle and the fan does not jerk at the begmning when switched on. Due to the entire surface area of the bolt head being in contact with the flat portion of the respective flange of the shackle chp, stress or load distribution on the bolt head is uniform. For the above reasons the suspension shackle of the 5 invention is simple in construction, easy and less time consuming to make and assemble and reliable and economical. Because the shackle chp is bolted to the suspension tube, it offers flexibility to the customer to cut and reduce, the tube length or to replace the tube by a different one.

l o The above embodiment of the invention is by way of illustrative example and should not be construed to be limitative of the scope thereof. Several variations of the invention are possible without deviating from the scope thereof. For instance, besides bolting, the shackling chp may be fitted to the suspension tube by any other known arrangement. The earthing

15 terminal is optional. The insulator may be securely located in the curved portion for instance by forming dimples in the shackle chp and locating the arms of the insulator in the dimples. There may be more than two arms and cooperating slots. Such variations are to be construed and understood to be within the scope of the invention.

20

Claims

1) An electric ceiling fan suspension shackle comprising a U-shaped shackle chp defining a curved portion and a pair of confronting flanges defining a flat portion along the centre thereof, the flanges being profiled to sit over the suspension tube in close contact therewith and fitted onto the suspension tube with known arrangement such as nut and bolt assembly and split pin; and a U-shaped resihent material insulator corresponding to the curved portion of the shackle chp and adapted to be securely located therein, the suspension tube along with the fan being suspended against the insulator in a hook anchored on the ceiling.

2) A suspension shackle as claimed in claim 1, wherein the curved portion of the shackle chp is provided with outwardly directed collars at the sides and the insulator is provided with outwardly directed projections at the sides adapted to abut the collars, the insulator being further provided with protruding arms along the outer surface adapted to be engaged in matching slots in the curved portion to securely locate the insulator in the curved portion.

3) A suspension shackle as claimed in claim 1 or 2, wherein one of the flanges is provided with an earthing terminal.

4) A suspension shackle as claimed in any one of claims 1 to 3, wherein the shackle chp is made of mechanically strong material such as mild steel sheet.

5) A suspension shackle as claimed in any one of claims 1 to 4, wherein the insulator is made of resihent material such as rubber. 6) An electric ceiling fan suspension shackle substantially as herein described particularly with reference to Figs 1 to 11 of the accompanying drawings.