US3247893A

US3247893A - Structural device

Info

Publication number: US3247893A
Application number: US317586A
Authority: US
Inventors: James A Ford
Original assignee: Kirsch Co
Current assignee: Cooper Industries LLC
Priority date: 1963-10-21
Filing date: 1963-10-21
Publication date: 1966-04-26
Anticipated expiration: 1983-04-26

Description

April 26, 1966 J. A. FORD STRUCTURAL DEVICE Filed 001;. 2.1, 1963 INVENTOR J/4M56' A FORD United States Patent 3,247,893 STRUCTURAL DEVICE James A. Ford, Sturgis, Mich, assignor to Kirsch Company, Stnrgis, Mich a corporation of Michigan Filed Oct. 21, I963, er. No. 317,586 Ill Clairns. (Cl. 160-345) This invention relates in general to drapery rod structure and, more particularly, to the arrangement of a pair of wall brackets with the two parts of a telescoping drapery rod for mounting said drapery rod upon a wall structure, said brackets having opposing cam locks for engaging said rod and preventing lengthwise movement of said parts toward each other when a drapery, which is supported thereon, is moved along said rod by a drapery cord in a substantially conventional manner.

Manufacturers and users of traverse type drapery rods have for many years been confronted with the problem of holding the two parts of a telescoping drapery rod against further telescoping movement when the drapery cord is pulled. That is, movement of the draw cord, in either an open or closed position, is opposed by the drag or weight of the draperies upon the rod. Thus, this resistance to movement is converted into forces applied to the pulleys, which forces tend to urge the two parts of the rod together.

It is common practice to support a two piece, telescoping traverse rod at a window by a pair of intermediate brackets which are connected to the rod between its ends and to the window casing near the top thereof. Thus, the opposite ends of the traverse rod extend beyond the casing of the window, hence beyond said brackets, so that the draperies can be moved completely clear of the lights in the window. The draw cord for the draperies is usually mounted upon the drapery rod in a substantially conventional manner so that the free ends of the draw cord hang from one extreme end of the rod.

Standard end brackets may be secured to the pulley housings on the opposite ends of the drapery rod so that the drapery return at the opposite ends of the rod can be supported adjacent the wall. However, these end brackets are often not connected to the wall in order to avoid putting holes in the wall. Accordingly, these end brackets are not able to serve one of their usual purposes,

i.e., to oppose telescoping movement of the drapery rod I in the usual manner. Further, even when the end brackets are fastened and do function somewhat to prevent, or at least oppose, the telescoping movement of the rod sections, they will often assume a toed in position and consequently present an unsightly appearance.

Insofar as I am aware, the intermediate brackets which are mounted upon the window have never been specifically designed for positively preventing such telescoping movement of the traverse rod parts. Thus,.the normal operation of the drapery draw cord tends over a period of time to cause the drapery rod parts to slide through these intermediate brackets, particularly if the brackets have been firmly secured to the casing. Ultimately, the drapery rod may be shortened to the point where the drapery cannot be moved completely clear of the lights in the window. Moreover, the slipping of the drapery rod through the existing intermediate brackets tends to chip or scratch the finish on'the rod and thereby damage its appearance.

This problem occurs whether the drapery rod is rigged to move a pair of draperies in opposite directions or to move a single drapery in both directions. That is, both forms of operation apply forces to the parts of the rod which urge them together.

Accordingly, the objects and purposes of this invention have been to provide:

(1) A traverse rod construction including telescop- 3,247,893 Patented Apr. 26, 1965 ing rod sections for use in adjustable traverse rod installations wherein the brackets are designed to oppose and prevent appreciable movement of the rod members telescopingly toward each other in response to the forces created by normal operation of the draw cords but instead the traverse rod sections cooperate with said brackets and utilize said forces to hold said rod members and brackets firmly in a preselected position with respect to each other.

(2) A pair of cooperating, intermediate, mounting brackets for engaging the two parts of a telescoping traverse rod, said brackets having oppositely acting, easily actuated mechanisms which positively oppose telescoping movement of the rod by the normal forces produced when the traverse draw cord is operated to move the drapes along the traverse rod;

(3) A pair of mounting brackets, as aforesaid, which can be easily adapted for use with a variety of traverse rod constructions, which are inexpensive to manufacture, which are relatively small and inconspicuous so that they do not detract from the appearance of the traverse rod, which include rod engaging mechanisms that are very easy to operate and can be easily and quickly disconnected from the traverse :rod when it becomes desirable to remove the traverse rod from its support upon a wall; and which are so designed that they do not interfere with the normal movement of the rod when the pulley housings are disconnected from the usual end brackets which have been secured to the walls.

(4) A pair of cooperating mounting brackets, as aforesaid, which are very easy to install, which are adjustable,

which can be used as either a sole support or an augmenting support of the traverse rod and which are as effective for use on a double draw as on a single draw drape assembly, and which are particularly well suited for supporting traverse rods where the conventional end brackets cannot be mounted upon the supporting surface in a conventional manner.

Other objects and purposes of this invention will become apparent to persons familiar with this type of equipment upon reading the following descriptive material and examining the accompanying drawings, in which:

FIGURE 1 is a broken top view of a traverse rod assembly including a pair of intermediate mounting brackets embodying the invention. 4

FIGURE 2 is a perspective view of a left-hand mounting bracket and a fragment of one type of traverse rod with which said mounting bracket can be used.

FIGURE 3 is a sectional view taken along the line III-J11 in FIGURE 1.

FIGURE 4 is a top plan view of the rod engaging member of said left-hand mounting bracket in a substantially unlocked position.

FIGURE 5 is a sectional view taken along the line V- V in FIGURE 4 and rotated degrees clockwise.

FIGURE 6 is a bottom view of the rodengaging members of the mounting brackets shown in FIGURE 1.

FIGURE 7 is a sectional view taken along the line VII-VII in FIGURE 5.

For convenience in description, the terms upper, lower and words of similar import will have reference to the intermediate mounting brackets of the invention and parts associated therewith as appearing in FIGURE 3. The terms left, right and words or word combinations of similar import will have reference to the intermediate brackets of the invention and the traverse assemblies associated therewith as appearing in FIGURE 1. The terms front, rear and words of similar import will have reference to the right and left sides, respectively, of the intermediate brackets as appearing in FIGURE 3. The terms inner, outer and derivatives thereof will have reference to the geometric center of said brackets and parts of the traverse assembly associated therewith.

General construction The objects and purposes of the invention, including those set forth above, have been met by providing a pair of similar, cooperating mounting brackets which are capable of releasably engaging a substantially conventional telescoping traverse rod between the ends thereof and supporting said traverse rod in a substantially horizontal position upon and adjacent an upright wall structure. Each mounting bracket is comprised of a rod engaging member and a wall attaching member which are releasably, and may be adjustably, connected together. The wall attaching members of each mounting bracket may be and preferably are identical. The rod engaging members are preferably mirror images of each other and they have oammed clamping levers which are arranged to oppose telescoping movement of the parts of the traverse rod which they engage. That is, the pair of mounting brackets can positively oppose movement of the two parts of a telescoping traverse rod toward each other. However, the cammed levers are arranged so that the two parts of the traverse rod can be forced away from each other without damaging the brackets or the rod.

The intermediate mounting bracket of the invention can be used toaugment the support provided by the usual end brackets, especially where the traverse rod is relatively long, hence, relatively heavy. The intermediate brackets, if used with the conventional end brackets, will oppose telescoping of the rod parts and, therefore, the tendency for the end brackets to be toed in by operation of the traverse draw cord.

Detailed construction The traverse rod assembly 10 (FIGURE 1), which 1 includes the

intermediate mounting brackets

22 and 23 of the invention, is usually mounted on an upstanding wall structure 11, and usually adjacent a window frame 12. Briefly, and for example, the traverse rod assembly 10 may include a substantially conventional traverse rod 14 having conventional

traverse pulley housings

16 and 17 mounted on the end-s thereof. Tnaverse pulleys 15 and cord 15a are disposed within the housings and the rod, respectively, in a known manner. It may be desired, particularly in the case of a long and heavy traverse rod assembly, to support the extreme ends of the traverse rod 14 by means of the housing or

end brackets

18 and 19, which are also used to support the drapery returns adjacent the wall structure 11. However, in this illustration of the invention, the

end brackets

18 and 19 are not secured to the wall structure and, therefore, could be omitted, if desired.

The above-described construction, except for the

brackets

22 and 23, may be conventional and, therefore, is here disclosed only to illustrate one of many possible operating environments for the

intermediate brackets

22 and 23 of the invention, described hereinafter.

The drapery or traverse rod 14 (FIGURE 1) is preferably comprised of an elongated inner rod member 21 having partially telescoped thereover an elongated outer rod member 22, which are engaged respectively by the

intermediate brackets

23 and 24, which are in turn mounted upon the upper portion of the window frame 12. The

mounting brackets

23 and 24 preferably include identical and L-shaped support or wall engaging members 26 and 27, which respectively support a pair of

rod engaging members

28 and 29. The

rod engaging members

28 and 29 are mirror images of each other for reasons appearing hereinafter. Since the support elements 26 and 27 are identical in this instance, it is believed that a detailed description of the element 26, only, will be sufficient.

The support member 26 (FIGURES 2 and 3) has an essentially vertical flange 31 with a plurality of holes 32 therein for receiving suitable fastening means, such as the screws 33, therethrough to fasten the flange to the window frame 12. The support member 26 also has an essentially horizontal flange 34.

The rod engaging member 28 (FIGURES 2, 3, 4 and 5) includes a gripping element 36 which has pivotally attached thereto a clamping element 37. The gripping element 36 is attached near one end thereof to the horizontal flange 34 of the support element 26 by any convenient means, such as a screw 38 which extends through a hole 40 in the flange 34 and is engaged by a nut 39. Matching,

elongated offsets

41 and 42 are provided in, and lengthwise of, the gripping element 36 and the horizontal flange 34, respectively. The offset 42 is received into the recess 41a created by the offset41 to prevent rotation of the rod engaging member 28 with respect to the support member 26 when the nut 39 is tight on the screw 38.

The forward end of the gripping element 36 has a downwardly and slightly rearwardly extending book 43 (FIGURE 3) for gripping the upper edge portion 44 0f the front side on the inner rod member 21 of the traverse rod 14. The gripping element 36 has a depressed portion 46 centrally located on the under side thereof which may be formed by stamping a depression 47 in the upper side of said gripping element 36 at the outer end of the recess 41a. A conventional rivet 48 may be used to pivotally connect the clamping element 37 near the middle thereof to the depressed portion 46, so that the ends of said clamping element are spaced from the gripping element. Thus, the clamping element 37 is mounted for pivotal movement about an axis substantially perpendicular to the

elements

36 and 37.

The clamping element 37 (FIGURE 5) includes a downwardly stepped and essentially horizontal rearward portion having an elongated opening 49 through which the nut 39 (FIGURE 3) can be reached when the clamping element 37 is in its normal position of FIGURE 6, as hereinafter described.

The clamping element 37 has an enlarged slot 51 adjacent its rear edge for reception of a tool, such as the blade of a screw driver, whereby said clamping element 37 may be engaged and pivoted about the rivet 48. The forward end of the clamping element 37 is slightly raised and has a curved forward edge portion defining a cam 54. The cam 54 is here comprised of a degree segment of a circle which extends from the front edge of the element 37 around one corner to the side edge thereof, the distance from the center of the rivet 48 to the cam edge increasing toward the front edge of the element 37 Thus, as the clamping element 37 is pivoted from its open position of FIGURE 4 to its closed position of FIGURE 6, the distance between the hook 43 and the cam edge 54 is gradually decreased.

The inner rod member 21 of the drapery rod 14 has a rearwardly extending flange portion 56 which is gripped between the gripping element 36 and the clamping element 37 when said element 37 is in its. closed position of FIGURES 3 and 6. At the same time, the clamping element wedges the edge 44 of the rod member 21 into contact with the hook 43 of the gripping element 36 and, hence, supports the drapery rod 14. The configuration of the cam 54 is such that the flange portion 56 will be released when the clamping element 37 is rotated about its pivot point to its open position of FIGURE 4. The upper surface of the forward edge of the clamping element 37 is serrated at 57 to grip more securely the flange portion 56 of the drapery rod 14.

The gripping element 36 has a downwardly projecting and preferably integral stop finger 58, which is located rearwardly of the rivet 48 to stop pivotal movement of the clamping element 37 when it reaches its open and also its fully closed position. Thus, the stop finger positively prevents that pivotal movement of the member 37 which might damage the rod member 21 and thereafter permit the telescoping movement.

The rod engaging member 29 (FIGURE 1) is similar to the rod engaging member 28 described in detail hereinabove, except that it is essentially a mirror image of 'said rod engaging member 28. Thus, referring to FIG- URE 6, by providing the cam edges 54 and 54a at opposite front corners of the

elements

37 and 37a, respectively, member 28 prevents movement of the elongated rod member 21 leftwardly while member 29 prevents rightward movement of the outer member 22, so that telescoping of the

elements

21 and 22, with the consequent contraction of the drapery rod 14, is prevented. It will be noted that certain parts of the rod engaging member 29, such as the finger 58, are in reversed positions from those of the corresponding parts in the member 28. Moreover, for example, the dimensions of certain parts in the member 29 may be proportionately larger than the dimensions of the corresponding parts in the rod engaging member 28 because the rod member 22 has a larger cross section than the member 21 so as to be capable of telescoping therewith. However, these parts of the rod engaging member 29 are functionally the same as the corresponding parts in the rod engaging member 28 and, hence, will be numbered with the same reference numerals with the suflix a added thereto.

Operation A drapery rod 14- may be supported entirely by the

intermediate brackets

23 and 24, or a combination of the intermediate brackets and the

end brackets

18 and 19. Normally, the support members 26 and 27 are secured to the supporting wall structure 11, such as the window frame 12, by the screws 33 so that the flanges 34 and 34a are on top and are essentially horizontal. The

rod engaging members

28 and 29 are then preferably installed upon the support members 26 and 27, respectively. The

telescoping rod members

21 and 22 are now moved into their proper relative positions, as shown in FIGURE 1 by means of screws 38 and nuts 39. The

members

28 and 29 are adjusted for the proper distance to the wall, after which the nuts 39 are tightened.

The clamping

elements

37 and 37a are pivoted into their open positions as shown in FIGURE 4 with respect to element 37. The traverse rod 14 is then placed under the

members

28 and 29 and moved upwardly so that its forward edge portion 44 bears against the

hooks

43 and 43a on the gripping elements 36 and 36a of said rod. The clamping

elements

37 and 37a are rotated into their operative or closed positions of FIGURE 6, whereby they engage the flange portions 56 and 56a of the

rod members

21 and 22, sothat said drapery rod 14 is supported with respect to the supporting wall surface 11.

When the drapery rod 14 is thus installed, the left intermediate bracket 23 will prevent rightward movement of the rod member 21 and the right intermediate bracket 24 will prevent leftward movement of the rod member 22. In fact any urging of the

rod members

21 and 22 toward each other will simply cause their respective rod engaging members to grip the

rods

21 and 22 more securely, due to the camming action of the clamping

elements

37 and 37a. Accordingly, the

brackets

23 and 24 will positively oppose the forces which are created by the operation of the traverse draw cords or the like when the traverse rod assembly is operated in a normal manner. The

serrated portions

57, 57a and the

fingers

58, 58a cooperate with the clamping

elements

37 and 37a to hold them in their closed position when such forces become excessive.

It will be apparent that, when the intermediate brackets are used with

conventional end brackets

18 and 19, the intermediate brackets prevent said end brackets from being toed in by the aforementioned forces which also cause the telescoping of the drapery rod 14.

Although a particular preferred embodiment of the invention has been disclosed above for purposes of illustration, variations or modifications thereof lying within the scope of the appended claims, are fully contemplated.

What is claimed is:

1. Traverse rod structure comprising in combination:

traveres rod means including telescoping rod members, at least one pulley at the outer end of each of said members and at least one draw cord arranged on and around said pulleys for effecting horizontal movement of a drapery suspended from said traverse rod, whereby normal operation of said draw cord will urge a relative movement of said rod members toward each other;

a pair of brackets each arranged respectively in engagement with one of said rod members and each of said brackets having gripping means releasably engageable with the respectively engaged one of said rod members, said gripping means each including a cam member pivotable into gripping engagement with the respectively engaged one of said rod members, said cam members being sensed oppositely with respect to each other and positioned with respect to each of said rod members in such a manner that said movement of said rod members toward each other will effect a tightening movement of each respective cam member;

whereby normal operation of said traverse rod will maintain said supporting cam members in tight condition for constant and firm supporting of said rod members and simultaneously the action of said cam members will prevent appreciable movement of said rod members telescopingly toward each other.

2. Bracket structure for mounting upon a support structure an elongated member having a pair of laterally spaced lengthwise edge portions, and for positively opposing lengthwise movement of said elongated member with respect to said support structure, comprising:

a pair of similar gripping elements, each gripping element having gripping means near one edge thereof engageable with one of the edge portions of the elongated member, the opposite edge of said gripping element extending laterally and substantially beyond the other edge portion of said elongated member;

means on said gripping elements for mounting same upon said support structure;

a pair of clamping elements which are substantially mirror images of each other, each clamping element being pivotally connected between the ends thereof to one of said gripping elements at a point. thereon spaced from said one edge thereof, and each clamping element'having a cam surface at one end thereof movable into snug engagement with the said other edge portion, whereby said elongated member is firmly gripped between said gripping means and said cam surface.

3. A structure according to claim 2 wherein the cam surface on each clamping element is constructed to positively oppose the lengthwise movement of said elongated member is one direction, and said clamping elements are arranged so that they both oppose said movement toward each other.

4. Mounting bracket structure for supporting a twopiece, telescoping traverse rod upon a Wall structure, said traverse rod having a pair of laterally spaced lengthwise edge portions facing in substantially opposite lateral directions adjacent the upper surface thereof, comprising:

a pair of elongated, substantially flat and similar gripping elements, eaoh element having hook means projecting downwardly therefrom near one end thereof for engagement with one of the edge portions on the traverse rod;

a pair of substantially fiat clamping elements which are substantially mirror images of each other, each clamping element being pivotally connected between the ends thereof to one of said gripping elements on the lower side thereof, each clamping element having near one end thereof a cam lock edge substantially defining a portion of an involute curve around the pivot axis of the clamping element, said cam edges being arranged so that their involute curves expand in opposite rotational directions, each cam lock edge being engageable with the other edge portion of said traverse rod for releasably land rigidly holding said traverse rod against and with respect to its corresponding gripping element; and

a pair of support members respectively and releasably connectible to said gripping elements and mountable upon said wall structure whereby said pieces of said traverse rod can be supported upon said wall structure so that telescoping movement of the two pieces of the rod is positively opposed.

5. A structure according to claim 4 wherein each gripping element has an integral finger adjacent one edge thereof and extending from said side thereof for engagement by the clamping element to limit pivotal movement thereof.

6. A bracket for engaging an elongated transverse rod having a pair of oppositely and laterally projecting edge portions adjacent the upper surface of the traverse rod, comprising:

an elongated, substantially flat gripping element having a downwardly projecting flange extending along one end edge thereof for snug engagement with and griping of one edge portion on the traverse rod, said gripping elements extending across said upper surface of said rod and beyond the other edge portion thereof;

an elongated, substantially flat clamping element pivotally connected between the ends thereof to said gripping element extending across said upper surface clamping element being on the lower side of said' gripping element and having an arcuate, cam edge near one end thereof substantially defining a portion of an involute curve around the pivot axis of the clamping element, said cam edge being in a position spaced from and opposing said flange when said gripping elernent and said clamping element are substantially parallel, said cam edge being engageable with the other edge portion of said rod for holding same tightly against said flange; and

downwardly projecting stop means on said gripping element adjacent one edge thereof and engageable by said clamping element for preventing pivotal movement thereof in a clamping direction when said clamping and gripping elements are substantially parallel.

7. A bracket according to claim 6 wherein the cam edge of said clamping element is spaced from said flange for reception therebetween of said other projecting edge portion;

wherein said clamping element has adjacent said cam edge a serrated surface facing said gripping element; and

including an L-shaped support member having a flange and connecting means for releasably securing said flange to said gripping element near the other end thereof.

8. Bracket structure for mounting upon a support structure an elongated member having a pair of laterally spaced lengthwise edge portions, and for positively opposing lengthwise movement of said elongated member with respect to said support structure, comprising:

a pair of similar gripping elements, each gripping element having gripping means near one edge thereof engageable with one of the edge portions of the elongated member, the opposite edge of such gripping element extending laterally and substantially beyond the other edge portion of said elongated member;

means on said gripping elements for mounting same upon said support structure;

a pair of clamping elements, each clamping element being pivotally connected between the ends thereof to one of said gripping elements at a point thereon spaced from said one edge thereof, and each clamping element having a clamping surface at one end thereof movable into snug engagement with said other edge portion of said elongated member, said clamping surfaces being shaped in different manners so that they respectively oppose longitudinal movement of said elongated member in opposite directions, whereby said elongated member is firmly gripped between said gripping means and said clamping surfaces and is held against longitudinal movement in either direction with respect to said support structure.

9. A bracket for engaging an elongated traverse rod having a pair of oppositely and'laterally projecting edge portions adjacent the upper surface of the traverse rod, comprising:

an elongated, gripping element having a downwardly projecting flange extending along one end edge thereof for snug engagement with and gripping of one edge portion on the traverse rod, said gripping element extending across said upper surface of said rod and beyond the other edge portion thereof;

an elongated, substantially flat clamping element pivotrally connected between the ends thereof to said gripping element between the ends thereof, said clamping element being on the lower side of said gripping element and having an arcuate, cam edge near one end thereof substantially defining a portion of an involute curve around the pivot axis of the clamping element, said cam edge being in a position spaced from and opposing said flange when said gripping element and said clamping element are substantially parallel, said cam edge being engageable with the other edge portion of said rod for holding same tightly against said flange.

10. A bracket for engaging an elongated traverse rod having a pair of oppositely and laterally projecting flange portions adjacent the upper surface of the traverse rod, comprising:

an elongated, gripping element having a downwardly projecting flange extending along one end edge thereof for snug engagement with and gripping of one flange portion of the traverse rod, said gripping element extending across the upper surface of the rod and beyond the other flange portion thereof;

an elongated, substantially flat, substantially horizontally extending, plate-form clamping element pivotally connected to said gripping element, said clamping element being on the lower side of said gripping element and having a cam edge at one end thereof, said cam edge being spaced from said flange of said gripping element and the lengthwise extent of said cam edge extending in a generally horizontal direction, whereby when said gripping element and said clamping element are substantially vertically aligned, said cam edge is disposed beneath the other flange portion of said rod and is engageable with said rod for holding said rod tightly against said flange of said gripping element.

References Cited by the Examiner UNITED STATES PATENTS HARRISON R. MQSELEY, Primary Examiner.

Claims

1. TRAVERSE ROD STRUCTURE COMPRISING IN COMBINATION: TRAVERSE ROD MEANS INCLUDING TELESCOPING ROD MEMBERS, AT LEAST ONE PULLEY AT THE OUTER END OF EACH OF SAID MEMBERS AND AT LEAST ONE DRAW CORD ARRANGED ON AND AROUND SAID PULLEYS FOR EFFECTING HORIZONTAL MOVEMENT OF A DRAPERY SUSPENDED FROM SAID TRAVERSE ROD, WHEREBY NORMAL OPERATION OF SAID DRAW CORD WILL URGE A RELATIVE MOVEMENT OF SAID ROD MEMBERS TOWARD EACH OTHER; A PAIR OF BRACKETS EACH ARRANGED RESPECTIVELY IN ENGAGEMENT WITH ONE OF SAID ROD MEMBERS AND EACH OF SAID BRACKETS HAVING GRIPPING MEANS RELEASABLY ENGAGEABLE WITH THE RESPECTIVELY ENGAGED ONE OF SAID ROD MEMBERS, SAID GRIPPING MEANS EACH INCLUDING A CAM MEMBER PIVOTABLE INTO GRIPPING ENGAGEMENT WITH THE RESPECTIVELY ENGAGED ONE OF SAID ROD MEMBERS, SAID CAM MEMBERS BEING SENSED OPPOSITELY WITH RESPECT TO EACH OTHER AND POSITIONED WITH RESPECT TO EACH OF SAID ROD MEMBERS IN SUCH A MANNER THAT SAID MOVEMENT OF SAID ROD MEMBERS TOWARD EACH OTHER WILL EFFECT A TIGHTENING MOVEMENT OF EACH RESPECTIVE CAM MEMBER; WHEREBY NORMAL OPERATION OF SAID TRAVERSE ROD WILL MAINTAIN SAID SUPPORTING CAM MEMBERS IN TIGHT CONDITION FOR CONSTANT AND FIRM SUPPORTING OF SAID ROD MEMBERS AND SIMULTANEOUSLY THE ACTION OF SAID CAM MEMBERS WILL PREVENT APPRECIABLE MOVEMENT OF SAID ROD MEMBERS TELESCOPINGLY TOWARD EACH OTHER.