GB2294386A

GB2294386A - Inclination adjustment means for an arm of a loudspeaker support

Info

Publication number: GB2294386A
Application number: GB9519707A
Authority: GB
Inventors: Richard Paul Woods
Original assignee: AUDIO AND VISION FURNITURE Ltd
Current assignee: AUDIO AND VISION FURNITURE Ltd
Priority date: 1994-10-29
Filing date: 1995-09-27
Publication date: 1996-05-01
Anticipated expiration: 2015-09-27
Also published as: GB9519707D0; GB9421807D0; GB2294386B

Abstract

A support bracket for a loudspeaker has an arm (27) mounted for pivotal upwards and downwards movement by means of a cylindrical pivot member (28) fitted between opposite sides (29, 30) of a plate metal housing part (11). The pivot member has a threaded bore therethrough in which is threadedly engaged a shaft (19) provided with a screw-thread (22), a thumb-wheel (26) on the shaft being rotatable to cause rotation of the shaft. As the shaft is otherwise held captive between upper and lower walls of the housing part (11) rotation of the shaft causes the pivot member to move along the shaft. Accordingly the angle of inclination of the arm member relative to the upper wall (12) of the housing can be varied, with a stop (31) at the upper end of the arm member engaging said upper wall. <IMAGE>

Description

INCLINATION ADJUSTMENT MEANS FOR AN ARM This invention relates to means for adjusting the angle of inclination of an arm member or equivalent relative to a reference surface, and has particular application to the adjustment of the angle of tilt of an arm member of a support bracket for a loudspeaker.

Such a bracket is normally fixed to a vertical surface, in use, and one known method of adjustment of the tilt of the arm member involves the use of a manually operable adjustment screw which is arranged with its end bearing against the arm member at the side of the fixed pivot of the arm member remote from loudspeaker engagement means carried at one end of the arm member. The screw is threadedly engaged in a housing of the bracket so that by turning the screw its end moves towards or away from the housing, resulting in decreased or increased tilting of the arm member relative to the horizontal.

An object of the invention is to provide improved means of adjusting the anF,!c of inclination of an arm member relative to a reference surface.

According to the invention means for adjusting the angle of inclination of an arm member relative to a reference surface comprises an arm member, a pivot member having an axis about which the arm member is mounted for pivotal movement, and adjustment means for moving said axis towards or away from said reference surface.

Preferably the adjustment means includes a threaded shaft on which the pivot member is threadedly received. The shaft may be carried by a housing1 a surface of which constitutes said reference surface, such that rotation of the shaft effects said movement of the axis towards or away from a surface of the housing.

Desirably the shaft passes through a diametral bore extending through the pivot member, said bore having internal screw-threading complementary to the screw-threading on the shaft. Conveniently the shaft has an adjustment member at an end thereof outside the housing for manual adjustment of the inclination of the arm member.

Advantageously the arm member can swivel about a central longitudinal axis of the shaft. An end of the arm member adjacent the pivot member has an upper abutment member which can engage an inner, upper surface of the housing, which constitutes said reference surface, to provide for further upwards tilting of the arm member from the horizontal. The arm member preferably carries loudspeaker engagement means and is part of a support bracket intended to carry a loudspeaker.

The invention will now be described, by way of example, with reference to the accompany".fs drawings, n which: Figure 1 is a side view of a bracket for carrying a loudspeaker, the bracket incorporating adjustment means in accordance with the present invention, a cover of the bracket being shown in phantom, Figure 2 is an enlarged scrap view of part of the bracket of Figure 1, with an arm member shown in two alternative extreme positions of tilt, and Figure 3 is an enlarged, fragmentary view of one end of the arm member.

Although its application is not restricted thereto, the present invention is particularly intended for use in a support bracket for a loudspeaker. A bracket of this type has a part securable to a vertical wall surface, from which part an arm member forwardly extends. The arm member is of telescopic construction with upstanding abutments on the two parts of the construction respectively, between which the supported loudspeaker is clamped, in use. The invention will be described in relation to a bracket of this type.

As shown in the drawing, the bracket has a rear, housing part 11 which, as will be described, provides means for securing the bracket to a surface of a wall 10. The housing part is formed from metal plate and is shaped to a channel configuration with upper and lower walls 12, 13 respectively, integrally joined by a base wall 14. Remote from the base wall, opposite side edges of each wall 12, 13 are tapered, over part of their extent, in a horizontal plane, in a direction away from the base wall. The lower wall has a notch 13a in each of its sides for a purpose to be described.

The end of the upper wall 12 remote from the base wall has extending integrally from it an upwardly directed wall 15 which is angled rearwardly. At its upper extremity the wall 15 is bent to form a short end part 16 lying in the same plane as the base wall 14. Fixing holes 17, 18 are provided in the base wall 14 and end part 16 respectively to receive elements for fixing the housing part 11, and thus the bracket, to a flat surface, such as the vertical wall 10.

A pair of circular holes are provided in the upper and lower walls 12, 13, these holes having their respective axes aligned and parallel to the plane of the base wall 14. Extending between the upper and lower walls and passing through the holes is a shaft 19 of a headed screw 20. A head 21 of the screw lies a short distance below the outer surface of lower wall 13, while the shaft is mostly of plain circular section from said head for just over approximately one third of the length of the shaft.

Thereafter the remainder of the shaft has a screw-thread 22. A screwdriver slot is provided in the head.

The end of the shaft projecting above the outer surface of the upper wall 12 has a washer 23 (optional) and a lock nut 24 thereon, a slot 25 in the wall 15 being provided to allow access to the nut during assembly.

Carried on the shaft in the spacing between the head 21 and the outer surface of the lower wall 13 is a manual adjustment member which, in this embodiment, is in the form of a plastics material thumb-wheel 26.

This is keyed to a short square section of the shaft directly adjacent the head 21 so that rotation of the thumb-wheel 26 effects rotation of the screw 20. To this end, the screw is a rotatable fit in the holes in the upper and lower walls 12, 13.

The outer section 27 of a telescopic arm member of the bracket is, in this example, formed of square section tube, and near its end received in the housing, it has a cylindrical, metal pivot member 28 fitted between opposite sides 29, 30 respectively thereof. Opposite ends of the member 28 are received in respective slightly oversized holes in said sides 29, 30 so that, as will be described, the arm member can pivot, i.e. tilt up and down, about the axis defined by the pivot member 28.

The member 28 has a circular diametral bore through it midway between its ends, the bore being provided with a screw-thread engaging with, and thus complementary to, that on the shaft 19. The shaft 19 thus carries the pivot member 28, as shown best in Figure 3, and also extends through the arm member by virtue of respective elongated slots (not shown) in the upper and lower surfaces of the arm member, the slots extending lengthwise of said surfaces to allow tilting of the arm member relative to the shaft, as will be described.The end of the upper surface of the arm member has a transverse stop 31 thereon for engagement with the inner surface of upper wall 12 which acts as a reference surface for the tilt of the arm member, the engagement of the stop with said wall providing for further upwards tilting of the arm member from a horizontal position, i.e. where it is parallel to walls 12,13.

As shown in phantom in Figure 1 of the drawings, a plastics material cover 32 can be provided to shroud the housing part 11, with a generally square front opening 33 of the cover allowing access to the thumb-wheel 26 for manually altering the tilt of the arm member, as will be described. The cover can be a snap-fit onto the housing part by the respective vertical sides of the opening engaging behind the notches 1 3a.

The opening is suffIciently deep to allow the degree of tilting permitted by the adjustment mechanism, as well as being sufficiently wide to allow the desired degree of sidewards swivelling of the arm member, opposite side edges of the opening in the cover here acting as respective stops in opposite directions of swivel.

With the pivot member at the lowest part of the thread on the shaft, i.e.

adjacent where the unthreaded part of the shaft terminates, (as shown in phantom in Figure 2), the weight of the arm assembly, with or without a loudspeaker thereon, is such that the arm assembly is at its maximum degree of (downward) tilt relative to the reference surface constituted by the inner surface of upper wall 12, which, in use, is horizontal. In this position, the stop 31 engages said inner surface, with the underside of the arm assembly clear of the lower wall 13 and adjacent thumb-wheel.

To move the arm assembly to a position where it is less tilted, the thumb-wheel is rotated in the appropriate direction. This causes corresponding rotation of the shaft 19. Since the shaft is restrained between the walls 12 and 13, the rotation is transmitted to the pivot member 28 through the interengagement of the threads, whereupon the member 28 moves upwards on the threaded part of the shaft, towards the wall 12. As this occurs the stop 31 remains engaged against the inner surface of wall 12, with the result that the arm member is caused to pivot about the member 28 thereby reducing its angle of tilt. Once adjusted, the thread interengagement referred to keeps the arm member in that position unless the thumb-wheel is again operated.

The adjustment described can be effected to move the arm to a horizontal position, i.e. where there is no tilt, (as in Figure 1), and possibly beyond this so that it is tilted slightly upwardly (Figure 2i. The limit at this end of the tilt adjustment procedure is when the upper surface of the arm member engages the upper wall 12 and/or the upper edge of the cover opening. Alternatively the thread on the shaft could be terminated short of the free end thereof to limit the upward movement possible for the pivot member.

In addition to the arm member tilting, it is also able to swivel in a horizontal or generally horizontal plane i.e. a plane parallel or generally parallel to the walls 12, 13, by moving about the axis defined by the shaft 19. Normally the weight of the arm is such that if it is swivelled to one side or the other of its straight ahead position, there is sufficient friction between the pivot member 28 and the shaft 19 to cause the shaft to rotate as well. However it is possible that under some circumstances the pivot member, and thus the arm 27, could swivel around the shaft 19 while it remains stationary. As mentioned, opposite side edges of the opening 33 in the cover 32 limit the degree of swivel permitted.

Instead of the tilt of the arm member being limited by engagement of the stop 31 with the inner surface of the upper wall 12, it could be by engagement of a stop on the lower surface of the arm assembly with the inner surface of the lower wall 13, or by way of any combination of such engagements throughout the tilting or at different parts thereof. The reference surface to which tilt of the arm member is related can thus be the surface of wall 12 or 13.

Movement of the pivot member 28 could be effected by adjustment means other than those described and illustrated. For example rather than being carried by a screw, the pivot member could instead be formed with gear teeth along part of its length arid d thumb-wheel at one end. The screw 20 could be replaced by a member at least partly formed as a rack, the teeth of which are engaged by the gear teeth on the pivot member. By suitably arranging the rack in the housing and relative to the arm, and also the pivot member relative to the arm, rotation of the thumb-wheel, at a side of the housing, could be arranged to move the pivot member along the rack, i.e. towards or away from the reference surface, so as alter the tilt of the arm member.

Claims

1. Means for adjusting the angle of inclination of an arm member relative to a reference surface, comprising an arm member, a pivot member having an axis about which the arm member is mounted for pivotal movement, and adjustment means for moving said axis towards or away from said reference surface.

2. Means as claimed in Claim 1, wherein the adjustment means includes a threaded shaft on which the pivot member is threadedly received.

3. Means as claimed in Claim 2, wherein the shaft is carried by a housing, a surface of which constitutes said reference surface, such that rotation of the shaft effects said movement of the axis towards or away from said housing surface.

4. Means as claimed in Claim 2 or Claim 3, wherein the shaft passes through a diametral bore extending through the pivot member, said bore having internal screw-threading complementary to the screwthreading on the shaft.

5. Means as claimed in Claim 3, wherein the shaft has an adjustment member at an end thereof outside the housing for manual adjustment of the inclination of the arm member.

6. Means as claimed in Claim 5, wherein the adjustment member is a thumb-wheel.

7. Means as claimed in any one of Claims 3 to 6, wherein said reference surface is constituted by an inner upper surface of the housing, and an end of the arm member adjacent the pivot member has an upper abutment member which can engage said inner upper surface of the housing to provide for further upwards tilting of the arm member from the horizontal.

8. Means as claimed in any one of Claims 3 to 7, wherein the arm member can swivel about a central longitudinal axis of the shaft.

9. Means as claimed in Claim 8, wherein said swivelling of said arm member is limited by engagement with respective opposite sides of an opening in a cover engaged on said housing.

10. Means as claimed in Claim 9, wherein upward inclination of said arm member is limited by its engagement with an upper surface of said opening in the cover.

11. Means as claimed in any one of the preceding claims, wherein the adjustment means includes a threaded shaft on which the pivot member is threadedly received, and the shaft is carried by a housing, the housing being a one-piece metal plate construction providing means for securing it to a wall surface.

12. Means as claimed in any one of the preceding claims, forming part of a loudspeaker support bracket, with said arm member carrying loudspeaker engagement means.

13. Means for adjusting the angle of inclination of an arm member relative to a reference surface, substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.