US2981512A

US2981512A - Constant support hangers

Info

Publication number: US2981512A
Application number: US717349A
Authority: US
Inventors: Zollinger Alfred
Original assignee: Grinnell Corp
Current assignee: Grinnell Corp
Priority date: 1958-02-25
Filing date: 1958-02-25
Publication date: 1961-04-25
Anticipated expiration: 1978-04-25
Also published as: BE575990A; US2974915A; DE1153951B; FR1221120A; BE575991A; DE1205780B; GB899580A; FR1221121A; GB886496A

Description

April 1951 A. ZOLLINGER 2,981,512

CONSTANT SUPPORT HANGERS Filed Feb 25, 1958 3 Sheets-Sheet 1 [l m i A; 2 3- 7 6 2m 4 as 6 67 a /8 I \A /0 F l INVENTOR.

ALFRED ZOLLINGER ATTORNEY 1951 A. ZOLLINGER CONSTANT SUPPORT HANGERS April 25 Filed Feb, 25,' 1958 3 Sheets-Sheet 2 FIG. 5

INVENTOR. ALFRED ZOLLINGER' AT TOR Y ited States F 2,981,512 CONSTANT surron'r moans Aime Zollinger, Providence, n.1,, assignor to Grinnell Corporation, Providence, KL, a corporation of Dela- This invention relates to improvements in constant support'hangers for supporting loads subject to vertical movement within a limited range. o

'Itghas been proposed to support such loads (such as power plant piping) with motor-driven'constantsupport hangers instead of the spring hangers now widely used. As far as I 'am aware, however, all of these proposed motor-driven hangers have vertically disposed elongated screw members with nut members thereon which are movable vertically with respect thereto when one of these members is rotated. The difficulty is that this arrangement frequently occupies an excessive amount of vertical headroom because of the required length of the vertical screw member. Accordingly, it is desirable to provide a motor-driven hanger in which the screw membermay be disposed in other than a vertical position, and it is an object of the present invention to provide such a hanger.

Another object is to provide a constant support hanger having a motor-operated jack acting between a frame and a load-supporting lever pivoted to the frame.

Anothergobject of the invention is to provide a constant support hanger having a motoroperate'd jack acting between a frame and a load-supporting lever pivoted to the frame wherein a portion of the jack moves in a straight line with respect to the frame.

Another object is to provide a constant support hanger having a motoroperated jack with one portion-pivotally connected to a frame and another portion 'pivotally connected'to aload-supporting lever'pivote'd to the frame.

Another object is to'provide a constant support hanger havingamotor operated jack which acts between a frame and a load-supporting lever pivoted to the frame wherein theaforce :exer'ted by'the jack-is substantially proportional 'to the load.

Another object of the'present invention is to provide an/improved, compact, efficient and inexpensive motordriven' constant support hanger.

:-Fig.- 3 is ano'tl'ier'end elevation view taken on line 3-+3:df:Fig. 1; n n

' Fig. 4 is a cross-sectioned elevation view taken on line -'4-4 of Fig. 1; Fig.5 is a cross-sectioned side'elevation view of another embodiment of the present invention;

I Fi'g.:6is anend elevation view takenon line 6-6 of Fig. 5;

Patented Apr..25, 19.6.1

Fig. 6a is a perspective view of one of the parts shown inEig. 6.

Fig. 7 is another end elevation view taken on line 7-7 of Fig. 5;

Fig. 8 is a cross-sectioned side elevation view of another embodiment of the present invention taken on line 8-8 of Fig. 9; and

[Fig 9 is a cross-sectioned plan view taken .on line 9-9 of Fig. 8.

v.Refer'ring now more particularly to the drawings, Fig. 1 shows a constant support hanger according to the present invention which comprises a frame 10 having .-a rectangular horizontal top wall 12 and verticaliside walls 14 extending downwardly from opposite edges thereof. The top wall is secured to fixed overhead structureisuc'h as a building frame 15 by one or more suspension rods 16 threaded at their upper and lower ends. These ends extend throughsuitable holes 17 in the frame 15 and top wall 12 and are provided with nuts 18 in the usual manner. Located at one end of the frame (left end in 'Fig. 1,) is an end wall 20 which extends between the side walls and has its edges welded thereto and to the top wall. A speed reducing gear unit '22 is mounted on the outer surface of this end Wall 20 and secured thereto by bolts 24. An electric motor 26 adjacent the gear unit 22'is similarly bolted to the top wall 12 by bolts 27. Sheaves 28 and 29 on the motor and speed reducing gear unit, respectively, and a belt 30 connect the motor to the input shaft 31Yof the speed reducing gear unit. The output shaft 32 of this unit extends through an opening 32} in the end wall 20 and had one end 34 of a screw member 36 keyed to it. This screw member is axially aligned with respect to the output shaft, and has a shoulder 38 which is adjacent the end 34 and which bears against the rotating portion of a roller thrust bearing 40. This bearing, in turn, is mounted against the inner surface of the end Wall 20. The bearing and the shoulder 3:8 are concentrically positioned by an annular collar 42 secured to the inner surface of the end wall '20 and outstanding therefrom around the opening 33.

Beyond the shoulder 38 the screw member 36 is threaded at 44 and carries a nut member 46 which is formed in one end 47 of a tubular carriage 48. The

other end 51 of this carriage is closed by a plate 52 which engages a roller 53. This roller is mounted on an axle 54 the ends of which are journalled in a pair of lever plates '58 secured together in parallel spaced relationship by a spacer cylinder 59 and a pin 60. This spacer cylinder and this pin have their ends welded to the plates to form a single lever unit which is pivoted 'between the frame side walls 14 by a shaft 61 which passes through the cylinder 59 and plates 58 and has its ends journalle'd in suitable openings 64 in these frame 'side walls. The spacing between the lever plates 58 is sufficient to receive the plate 52 and permit it to move freely between them as the lever rotates about the axis of the shaft 61. Each of the ends of the carriage 48 is provided on its upper side with a bracket 64 having outwardly extending arm portions 66 which carry rollers 67 engaging tracks 68 secured opposite to each other on the inner surfaces 'of the side walls 14 and parallel to the axis of the screw member 36. These tracks and roller brackets serve to support and guide the motion of the carriage 48 as the nut member 46 moves along the threaded portion of the screw.

The pin 60 is engaged by the upper end 70 of a'loadsupporting rod 72 with spacers 73 maintaining this rod about midway'between the two lever plates. (See Fig. 2.) The lower end 74 of the load-supporting rod engages a bracket 76 welded to a pipe 77 which constitutes the load.

The various locations of the

shafts

60, 61 and 54 are selected in this arrangement of Fig. 1 so that when the lever unit rotates about the shaft 61 to accommodate the movement of the load the sleeve roller 53 on the shaft 54 remains in engagement with the plate 52 in the vicinity of the axis of the screw member 36.

A load sensitive switch unit 78 is located in the loadsupporting rod 72, and electrical leads 80 extend from this load sensitive switch to the motor 26 and to a power supply (not shown).

The operation of the device of Fig. 1 is as follows: Assume that the pipe section 77 weighs ten thousand pounds. The load sensitive switch device 78 is adjusted so that while the force exerted downwardly on the rod 72 is within 1% of ten thousand pounds the motor 26 remains inoperative, and the pipe section is held in the position shown. While the motor is inoperative the lever unit is prevented from rotating by the roller 53 engaging the plate 52 which in turn is held in position by the carriage 48 mounted on the threaded portion of the screw member 36. The pitch of the threads on the screw member 36 is small enough and the friction in speed reducing gear unit and motor is high enough so that the force exerted by the carriage against the screw member is unable to drive this screw member;

As the system is brought up to operating temperature and pressure the piping material expands. Assume that as a result of this expansion the section 77 supported by this hanger begins to move up, for example because of the increase in length of a riser (not shown) connected to this section. Such upward movement causes a portion of the ten thousand pound weight of the load to be transferred to other hangers or to piping connections remote from this hanger with the result that the force exerted on the load-supporting member 72 begins to decrease. When this force has decreased 100 pounds (1% of' the load) to 9,900 pounds the load sensitive switch 78 turns on the motor 26 to drive the speed reducing gear unit 22 to rotate the screw member 36 to drive the nut 46 to the right on the threaded screw member portion 44 and thereby rotatethe lever unit clockwise about its shaft 61. This causes an increase in the tension in the load-supporting rod 72, and when the load sensitive switch unit 78 senses that a force of 10,000 pounds is again being exerted it operates to turn oif the motor 26. Accordingly, the portion of the load which was thrown on to the other hangers and connections has been picked up again by this hanger. If the upward thermal movement of this pipe section continues the above-described operation will be repeated. This switch 78 may be set so that the device will exert any force within a selected range and this force will be exerted regardless of the position of the pipe or other load within its vertical range of movement.

The moment arm of the load about the ,pivot 61 (which is the perpendicular distance from this pivot to the line of action of the load on the lever unit) changes as the lever 58 rotates. Accordingly,'since the weight of the load remains substantially constant (constant except for the small changes above referred to) the moment of the load around the pivot 61 changes. Similarly the moment arm of the force exerted by the carriage member about the pivot 61 (which is the perpendicular distance from this pivot to a line through the axle 54 and parallel to the axis of the screw member 36) does not remain constant. These moment changes are substantially proportional when the angle (90) between the direction of the load (vertical) and the direction of the force exerted by the jack (horizontal) is substantially equal to the angle (90) between the lever arms 6154 and 61-60, and accordingly the force exerted by the jack is substantially constant, neglecting friction, because the load is substantially constant. If, on the other hand, the above-mentioned angles are not equal (for example, by the angle between the directions of the load and the jack being 90 and by the angle between the lever arms differing from 90 or vice versa) the moment arms are not proportional, and the force which the motor is required to exert is different for different positions of the load while the force on the load is being kept within the prescribed limits. These differences present no problem because the motor will furnish as much or as little force on the carriage as is required to maintain the predetermined force on the switch unit 78. While the embodiment of Figs. 1 to 4 has the above-identified angles substantially equal, the other embodiments illustrate arrangements in which these angles are not equal.

' In the embodiment of Figs. 1 to 4 the horizontal dimension of the device is substantially greater than its vertical dimension. The reason for this is that the screw member is disposed horizontally. This member will usually be one of the longest components, and whether the horizontal dimension is greater than the vertical dimension or vice versa will usually depend on the direction in which this member extends. It is true, of course, that the embodiment of Figs. 1 to 4 does not necessarily represent the most compact arrangement of components which is possible, and it is also true that devices of this kind could be designed in which the larger dimension would not be measured along the screw member. It is true, however, that in a view of the device like that of Fig. 1 (the width shown in a view like Figs. 2, 3 and 4 is almost always small) the relative size of the various dimensions can be controlled as desired by means of the direction changing lever unit which is characteristic of this invention.

Referring now to Figs. 5, 6 and 7, the embodiment shown there is similar to that of Figs. 1 to 4 except that the jack unit comprising the motor, speed reducing gear unit, screw member and nut member is pivoted to both the frame and lever. More specifically this embodiment comprises a frame 79 having a top wall 80 shown suspended from a building frame 82 by bolt and nut assemblies 84-86. This "frame also has side walls 88 the lower ends of which serve as journals for the ends of a pin 90. This pin passes through a cylindrical member 89 which has its ends welded to a pair of spaced lever plates 92. These plates lie between the frame side walls 88 and have aligned openings 94 which are spaced from the pin and serve as journals for shoulder screws 95 threaded into tapped holes 96 in the ends of a pair of trunnions '97 welded on opposite sides of a nut member 98. This nut member also has a central threaded aperture 99 at right angles to the common axis of the trunnions and receiving the threaded portion 100 of a screw member 102 which is similar to the screw member 36 of Figs. 1 to 4. A shoulder portion 104 on this screw member is contained within an annular collar 106 and bears against a roller thrust bearing also within this collar. The collar and hearing are mounted on a frame portion 108. Whereas the corresponding frame portion 20 in the embodiment of Figs. 1 to 4 was fixedly secured to the other parts of the frame, the portions 108 in Fig. 5 is provided with brackets 110 which are pivoted on -a shaft 112 the ends of which are journalled in the side frame portions 88. The'rotatable frame portion 108 carries a speed reducing gear unit 113 and motor 114. This motor has sheave 1-18 on its output shaft 119 and drives a sheave 120 on the input shaft 121 of the speed reducing gear unit through a .belt 122. The output shaft (not shown) of the speed reducing unit is keyed to and drives the screw member 102.

A pin 126 having its ends welded to the lever plates 92 is engaged by the upper end 127 of a load-supporting eye-rod 128 the lower end 129 of which engages a load. More particularly this lower end is connected to a bracket 130 which is in turn welded to a'pipe section 132. A

. load sensitive switch 134 is located in the eye-rod 128 and is connected to the motor 114 and to a source of power (not shown) by electrical leads 136.

The operation of this embodiment of Figs. 5 to 7 is like the load until it. is again between the prescribed limits. at

which point .the switch 134 will .turn 011 the motor. In. the embodiments of Figs. lito 4 the amountof rotation which can takeplace is limited by the fact thatli-f it exceeds a certain amountthe roller 53 would become disengaged from .the plate 52. With the arrangement of Figs. 5 to 7 this .can notthappen because of the pivotal connections, the other hand the constant horizontal disposition of the screw member in the embodiments of Figs. 1 to 4 does 'not obtain in the embodiments of Figs. 5 to 7. ,Referring'now to the embodiment of Figs. 8 and 9, this illustrates. that the pivotal connections of the jack unit with the frame and with the lever may be reversed.

.More particularly this embodiment comprises a frame 138l1aving a top wall 140 secured to fixed structure (not shown) by suspension rods 144. Dependingirom the top wall are frame side walls 146 providing journals 147 for the ends of a shaft 148 whichv passes through a cylindrical east-as heights, said height-adjusting means comprising a .lever whichris pivotally connected'to said anchor member and which has .a first arm connected to said supported'memher, said height-adjusting means further comprising a motor-driven jack which exerts force in a second direction and which is connected betweensaid anchor member and a second lever arm, said load sensitive element being located between said height-adjusting means andone of said members, and means for actuating said jaf inresponse to said relative movement to thereby actuate said height-adjusting means to change the said' height'of the hanger to compensate for said changes in force,'sa'i'd first and second lever arms forming a first tangle andsaid first and second directions forming a second angle which dif ters from said first angle throughout at least a substantial portion of said range. V i

2. A constant support hanger comprising 'a supported member to which a load acting in a first fixeddireoti'on member 149. Lever plates 159 are welded to the ends of thiscylindrical member to forma'levcr unit. These plates v150 are also: joined together by a shaft 152 the centerof ,whichis-engaged by the eye portions 158 of an eye-rod -160 and the ends of. which are welded to the plates 1150. This rod serves to suspend the load from the lever and includes. a load sensitive switch 162. The lo'wcr end,164 of therod ldtl engages a bracket 166 welded to the pipe 167which comprises the load. Electrical leads 163 extend from the switch 162 to a motor 170 mountedon a bracket 172 and to a power supply not shown. At apoint spaced from the

shafts

148 and 152 the lever plates .are provided with openings 174 which serve as journals for trunnions 176 extending from the sides of an outstanding cylindrical collar 178 welded to the bracket 172 This collar serves to retain a thrust bearing (not shown) and the shouldered end of a screw member 18dwhich bears against it in alignment with an opening in' the bracket. The output shaft of a speed reducing gear unit 181 passes through this opening and is keyed to the shouldered end of the screw member in the manner of the previous embodiments. The input shaft 182 of this speed reducing gear unit is provided with a sheave 184 which is driven by a belt 186 engaging a sheave 188 provided on the output shaft 190 of the motor 170.

The threaded portion 177 of the screw member 180 extends to and into threaded engagement with a block 192 which has a threaded aperture 194 therethrough receiving said screw member. This block is located between the side frame plates 146 by a pair of trunnions 196 which extend from its opposite sides and which are rotatably mounted on the side plates by shoulder screws 198. The extreme end of the screw member is provided with a stop 200 to prevent the screw member from being accidentally disengaged from the block 192.

The operation of this embodiment of Figs. 8 and 9 will be apparent from the foregoing description and from the description of the operation of the other embodiments.

I claim:

1. A constant support hanger comprising a supported member to which a load acting in a first direction is adapted to be applied, an anchor member for supporting said supported member and adapted to be secured to a fixed structure member, a load sensitive element for providing relative movement between said supported mem her and said fixed structure member in response to changes is adapted to be applied, an anchor member for support ing said supported member and adapted to be secured to a fixed structure member, a load sensitive element for providing relative movement between said supported member and said fixed structure member in responseto changes in force applied to said supported member by'the' load, means for adjusting the height of said hanger between said anchor meniber and said load through a range of heights, means for actuating saidheight-adjus ting means in response to said relative movement to thereby change the said height of the hanger to compensate for such changes in force, said height-adjustingmeans comprising a leverwhich is pivotally connected to said anchor member at a first point and pivotally connected tofthe supported member at a second point spaced from said first point and defining therewith a first lever arm, and said height-adjusting means further comprising a ,motordriven jack' having one part which is mounted on said anchor member and having another part which is movable with respect to said one part in a second fixeddirection with respect .to said anchor member and whichengages said lever at a third point also spaced from said first point and defining there witha second lever 'arm, said load sensitive element being .located between said height-adjusting means and one of said members, said first and .second lever arms forming a first fixed angle, and said first and second fixed directions forminga second fixed angle which differs from said first angle when said anchor member is secured to said fixed structure, whereby movement of the said other jack part with respect to said one jack part rotates said lever with respect to said anchor member around said first point and changes the said height of the hanger.

3. A constant support hanger comprising a supported member to which a load acting in a vertical direction is adapted to be applied, an anchor member for supporting said supported member and adapted to be secured to a fixed structure member, a load sensitive element which provides relative movement between said supported member and said fixed structure member in response to changes in force applied to said supported member by the load, means for adjusting the height of said hanger between said anchor member and said load through a range of heights, means for actuating said height-adjusting means in response to said relative movement to thereby change the said height of the hanger to compensate for such changes in force, said height-adjusting means comprising a lever which is pivotally connected at a first pivot to the anchor member and has an arm extending from said first pivot, said supported member being pivotally connected to said arm to provide a turning moment about the said first pivot, and said height-adjusting means further comprising a motor-driven jack having an elongated screw member mounted on said anchor member to extend in a fixed direction with respect thereto and having a. nut member on said screw member engaging another arm of the lever'to provide an opposite turning moment about said pivot, said load sensitive element being located between said height-adjusting means and one of said members, said fixed direction being substantially horizontal when said anchor member is secured to said fixed structure, and said lever arms forming an angle substantially different than ninety degrees.

4. A constant support hanger comprising a load-engaging member having a connection thereon to which a load acting in a vertical direction is adapted to be applied, a frame member having aconnection thereon at which said frame member is adapted to be secured to a fixed structure member, means for adjusting the vertical distance between said connections through a range of vertical distances, means located between said distance-adjusting means and one of said connections for detecting changes in force applied to said load-engaging member by said load and for controlling said distance-adjusting means to change said distance and compensate for said changes in force, said distance-adjusting means comprising a lever which is pivotally connected at a first pivot to the frame and which has first and second arms extending radially from said first pivot, said load-engaging member being pivotally connected to said first arm at a second pivot, said distance adjusting means further comprising a motordriven jack assembly connected to said frame at a third pivot and connected to said second lever arm at a fourth pivot, whereby the angle between said lever arms differs from the angle between said vertical direction and a line connecting said third and fourth pivots throughout at least a substantial portion of said range.

5. A constant support hanger for supporting a load which acts downward in .a verticalfirst direction and is subject to vertical movement within a limited range, said hanger comprising a frame member adapted to be fixed with respect to a fixed structure member, a lever pivoted to said frame member for rotation about a first axis, a load engaging member pivotally connected to said lever at a point thereon spaced from said first axis for rotation of said load engaging member with respect to said lever about a second axis parallel to said first axis and forming therewith a first lever arm, a motor-driven jack adapted to exert a force in one direction, said jack being mounted on said frame with its direction of force exertion fixed with respect thereto, said jack engaging said lever at a point thereon which is spaced from said first axis and which forms therewith a second lever arm, a control switch located between said jack and one of said members, said switch being responsive to changes in load to actuate said jack and rotate said lever about said first axis, to compensate for said changes in load, means for fixing said frame member to said fixed structure member with said axes horizontal and with said direction of jack force exertion at an angle to said vertical first direction which is equal to the angle between said lever arms.

6. A constant support hanger comprising a supported member to which a load acting in a first fixed direction is adapted to be applied, an anchor member adapted to be secured to a fixed structure member for supporting said supported member, a load sensitive element through which said supported member is supported and for providing relative movement between said supported member and said fixed structure member in response to changes in force applied to said supported member by the load, means for adjusting the height of said hanger between said anchor member and said load through a range of heights, said height-adjusting means comprising a bellcrank lever, which is pivotally connected to said anchor member and which has a first arm connected to said supported member, said height-adjusting means further comprising a motor-driven jack which acts in a second direction fixed with respect to said anchor member and which is connected between said anchor member and a second lever arm, said load sensitive element being located be tween said height-adjusting means and one of said members, and means for actuating said jack in response to said relative movement to thereby actuate said heightadjusting means to change the said height of the hanger to compensate for said changes in force, said first and second lever arms forming aninety degree angle, and means for securing said anchor member to said fixed structure member with said second direction forming a ninety degree angle with said first direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,248,730 Wood July 8, 1941 2,391,467 Loepsinger Dec. 25, 1945 2,568,149 Grabe Sept. 18, 1951 2,593,502 Thomson Apr. 22, 1952 2,709,057 Gould May 24, 1955