Field of Search:
108/1,6,9 297/374,376,375 292/263,276,275 16/138,171,139,140,182,191,166,178,179,137,82
Claims:
What is claimed is
1. A control arm assembly for hinged members, comprising a pair of arms pivotally connected together at the ends thereof and extending into free ends for pivotally connecting to a hinged member to be controlled in hinged position, one of said arms having an arcuate slot therein spaced from and centered with the pivot axis, the other of said arms having two openings aligned with said slot and being on opposite sides of the pivot axis of said arms for alternately receiving said fastener and thereby alternately forming a left-hand and a right-hand assembly, and a fastener extending through said arcuate slot and a selected one of said openings for releasably tightening said arms together and thereby releasably secure said arms in a set pivoted position.
2. The control arm assembly as claimed in claim 1, wherein said fastener includes a knob for hand gripping in tightening and loosening said fastener on said arms.
3. The control arm assembly as claimed in claim 1, wherein when said arms are pivoted to an extended position away from each other, said openings are located to be aligned with the respective ends of said slot.
4. The control arm assembly as claimed in claim 1, including a pivot member connected with said arms and forming the pivot axis therebetween, a friction disc disposed between said arms and having openings for said pivot member and said fastener.
5. A control arm assembly for hinged members, comprising a pair of arms, a pivot member extending through said arms for pivotally connecting said arms together, one of said arms having an arcuate slot spaced from and centered with the pivot axis, the other of said arms having two openings therein aligned with respective opposite ends of said slot when said arms are in a pivoted position away from each other, and a projecting member extending through a selected one of said openings and said slot for selectively forming a right-hand and a left-hand assembly.
6. The control arm assembly as claimed in claim 5, including a releasable fastener on said projecting member for selectively tightening on said arms and retaining them in a pivoted position.
7. The control arm assembly as claimed in claim 6, wherein said fastener and said projecting member are threaded together and said fastener is a knob for hand-tightening on said arms.
Description:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view, partly in section, of certain of the parts forming an embodiment of this invention.
FIG. 2 is a side elevational view of a preferred embodiment of this invention.
FIG. 3 is a bottom plan view of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawings show a control arm assembly which may be used on hinged members, such as the doors of the vehicles, including tractor cabs, to limit the degree to which the door can swing open, and to also hold the door in any degree of open position. Thus, two arms 10 and 11 are pivoted together by means of a pivot bolt 12 extending through aligned holes in the arms 10 and 11 at the inner ends of the arms 10 and 11. The outer ends of the arms 10 and 11 have pins or bolts 13 and 14, respectively, and these bolts 13 and 14 attach to the hinged member or door and to the frame relative to which the hinged member is movable. See for instance the general application shown in U.S. Pat. No. 3,141,694 where two arms are pivoted together for controlling the hinge movement of a hingedly mounted member.
Thus, the members 10 and 11 have central openings 16, such as the shown opening in the lower member 11 in FIG. 1, and they receive the pivot bolt 12 which is secured with a locking nut 17 shown in FIG. 2. Also, FIG. 1 shows the arms 10 and 11 with their ridges removed, and thus the sectioning is shown in FIG. 1 for better clarity in that type of showing. A friction disc 18 is disposed between the arms 10 and 11 and has a center opening 19 for also receiving the pivot boet 12. The disc 18 of course serves the purpose of increasing the frictional forces between the members 10 and 11 so that they can be more readily secured in a fixed pivoted position, by means described later.
FIGS. 1 and 3 show that the lower arm 11 has an arcuate slot 21 extending therethrough and centered about the pivot axis which is the axis of the bolt 12. Further, the slot 21 is semicircular.
The arm 10 has two openings 22 and 23, and these openings align with the respective ends of the slot 21 when the arms are in the fully extended position, which is the position shown in the drawings. A bolt 24 extends into one of the holes or openings 22 or 23, such as the hole 22 in which it is shown in the drawings, and the bolt 24 also then extends into the end of the slot 21. Finally, a fastener, in the form of a knob 26 is threadedly connected with the bolt 24 through the shank 27 of the fastener 26. Further, the bolt 24 extends through an opening 28 in the friction disc 18.
With the assembly as shown and described, it will be understood that the arms 10 and 11 can pivot from their extended positions shown and into the direction of the arrow designated A in FIG. 3, and this is termed a left-hand assembly. Where it is desired that the arms 10 and 11 pivot in the other direction, then the bolt 24 would be removed from the hole 22 and would be placed into the hole 23, and the arms would then pivot in the direction opposite to the one mentioned and described and this would be a right-hand assembly.
It will be further noticed that the bolt 24 is a carriage type bolt having a square head for fitting into the square openings 22 and 23, and also the disc 18 has another opening 29 which would receive the bolt 24 in the last assembly described.
With the assembly described, there need be only two arms 10 and 11, and the positioning of the bolt 24 determines whether the arms are in right-hand or left-hand assembly. The slotted arm 11 can be the bottom arm and can be secured to the frame on which the door is hinged. Also, the knob type fastener 26 is arranged with its shank 27 to abut the arm 11, at the shoulder 31, and thereby secure the arms 10 and 11 in a fixed pivoted position, as desired. With the axis of the bolt 24 and its attached fastener 26 offset from the pivot axis defined by the bolt 12, there is a mechanical advantage in tightening the knob 26 as it is offset from the pivot axis and thus the arms can be easily and efficiently secured in a set and selected pivoted position, compared to locking the bolt 12 on the pivot axis for securing the two arms in fixed pivoted position. In this arrangement, the bolt 12 is the pivot member, and the bolt 24 is a projecting member and it has the releasable fastener 26, for the purpose mentioned. Of course FIG. 3 shows the arms in their maximum position for the left-hand assembly shown, and they do not want to extend in an over-center position. Therefore, while the holes 22 and 23 align with the ends of the slot 21, the holes 22 and 23 cannot both align with the slot 21 at the same time since the holes 22 and 23 are slightly over-centered or off-set relative to the pivot axis defined by the bolt 12, and as seen in FIG. 3.