US2634079A

US2634079A - Clamp comprising two elements jammed on a rail

Info

Publication number: US2634079A
Application number: US185740A
Authority: US
Inventors: Frank J Surenda
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1950-09-20
Filing date: 1950-09-20
Publication date: 1953-04-07
Anticipated expiration: 1970-04-07

Description

April 7, 1953 F. SURENDA 2,634,079

CLAMP COMPRISING TWO ELEMENTS JAMMED ON A RAIL Filed Sept. 20, 1950 Patented Apr. 7, 1953 CLAMP COMPRISING TWO ELEMENTS JAMMED N ABAIL Frank-J. Surenda, Freedom, Pa., assignor to Allis- Chalmers Manufacturing Company, Milwaukee,

Wis.

Application September 20, 1950, Serial No. 185,740

3 Claims. 1,

This. invention relates to clamping devices and has particular. application to clamping objects against movement in. either of two directions and where the space for providing the clamping structure is very limited.v The clamping device claimed has application, for example, inside of casings for holding in position transformers or transformer accessories which are spaced therefrom inside of the casing, such as terminal boards.

Various arrangements have been utilized to clamp or hold transformers or other apparatus in place inside of casings. It has been usual practice to use clamping, members bolted to fixed structural parts of the casing and bolted to or acting against the transformer to hold the transformer or other apparatus in place. There are, however. several disadvantages to the usual arrangements of clamping. devices. Their primary disadvantages are the difiiculty of alignment of bolts or clamps with holes or notches in the fixed structure of the Casing and with the frame en closing the transformer, the necessity for the use of. both ordinary and locking nuts, the inability to exactly adjust the position of the clamping device to compensate for the variances in size of apparatus being. clamped, and the inability of some clamping devices to firmly lock against movement of the apparatus in either of two directions.

It is an object of this invention to provide an improved clampingdevice which avoidsthe above mentioned disadvantages.

Other objects of this invention are to provide I a clamping device which is a simple, compact,

inexpensive structure; is easily adjustable to any desired position; is easily locked and unlocked in. position even in very confined spaces; and earn not be inadvertently moved from the locked position.

Objects and advantages other than those above set forth will be apparent in the following description when read in connection with the accompanying drawing in which:

Fig. 1 is a side view of a transformer with its casing broken away to show an embodiment of an invention;

Fig. 2 is an enlarged side view of the clamping device shown in Fig. l in the clamped position; Fig. 3 shows the clamping device partly in section and in the same position as in Fig. 2;

Fig. 4.is a section view taken on the line IV -IV of'Fig. 2.

The apparatus shown in Fig. 1 is provided with a casing Ill and a cover I I which is usually adapted to be attached to the flanged upper ed of the casing by bolts o clamps (not shown). A transformer coil and core assembly [2 is located inside the casing and is provided with conductor cables l3 which are connected to bushingterminal members M of any suitable type. The core of the transformer is clamped by means of horizontal angle irons l6 and vertical angle irons I! which are'held in place by bolts. Guide members [8 and 19 may be attached to the angle irons at the top of the coil and core assembly by means of bolts 23, 24, respectively, and guide members 20, 2| are attached to the bottom of the assembly by

bolts

25, 26. A pair of T-shaped

resilient guide rails

21, 28 are welded to the sidewalls of the casing at diametrically opposite vertically extending positions. The guide members I 8. I9, 20 and 2| are grooved to cooperate with the guide rails so that the coil and core assembly may be lowered into the casing with the guide members sliding upon the guide rails. The bolts 25, abut the bottom of the casing to support and prevent downward movement of the assembly from its position inside the casing. The coil and core assembly is held in place against upward movement in the casing by means of clamping devices 29 and 30.

The clamping device generally indicated at 29 includes two similarly shaped resilient clamping elements 3!, 32 and a clamping bolt 33. Clamping' element 3| has at one end thereof a pair of

arms

34 and 35 which define a T-shaped slot. The dimensions of the slot are slightly larger than the cross sectional dimension of the T-shaped guide rail so as to permit the clamping device to slide easily upon the guide rail. The opposite end of clamping element 3| has a tapped hole 36' to receive the clamping bolt 33. The outline of element 3! shown in elevation in Fig. 2 defines a first portion of about one-third the length of the element of substantially constant width extending from the slotted end thereof to a point only a slight distance from the end of the slot. From that point, defined as the fulcrum line 37, to the other end of the element the upper edge of element 31 is cut away an amount equal to approximately one-third the thickness of the first mentioned portion.

The other of the two clamping elements 32 has the same general shape as element 3! and also has the same shape and size of T-shaped slot to slide easily upon. the guide rail. However, the end of element 32 opposite to the slotted end, instead of being tapped, has a round opening 38 there through of a size slightly larger than the size of the shank of bolt 33. The vertical cross sectional shape of the two clamping elements is the same.

As shown in Fig. 2, the top edge surface s: of element 32 is not flat but is defined by two planar surfaces which intersect at an obtuse angle approximately at the midpoint of the lengthwise dimension of the element.

After the coil and core assembly has been lowered into the casing,

elements

35 and 32 are slid down the rail 28 with their adjacent

similar surfaces

39 and 40, respectively, abutting against each other at the fulcrum line 3?. Clamping bolt 33 is inserted through opening 38 of element 32 and is screwed intotapped hole 36 of element 3! until the bottom of the bolt makes contact with guide member l8 and the head of the bolt makes contact with the fiat surface ll of element 32.

The bolt 33 is then screwed farther into element 3| causing elements 3! and 32 to rotate slightly about fulcrum line 3? until they engage the shank of the bolt and the headof the bolt is in contact with the flat upper surface ii of element 32. The resiliency of the cooperating two elements acting about the fulcrum line and the resiliency of the guide rail cause the edge surface M to exert a force on the head of the bolt preventing the b0 t from accidentally working loose; l

A simple three piece clamping device is thus provided which very effectively locks itself against the rail preventing its movement in either the upward or downward direction as viewed in Fig. 2 by the utilization of the coasting bolt and clamping elements which pivot about a fulcrum line relatively close to the guide rail against which they exert a force. The clamps thus prevent any upward movement of the coil and core assembly and hold the assembly down against the bottom of the casing.

By the illustration of Fig. 3 it is particularly intended to more clearly show the action of the clamping elements against the guide rail. When the clamping device is in its locked position there is a slight bending of the guide rail. The force Q5 which can be exerted through the jamming action of the clamp against the guide rail is greatly increased over the force 45 the bolt exerts on the clamping element. The comparison of the length oftherelatively long lever arm 47 from the bolt to the fulcrum linewith-thelength-of the relatively shorter lever arm 38 from the fulcrum line to the remotest point of contact of the T'- shaped slot edges with the guide rail represents the great increase of force exerted against the rail. Also the coaction of the two clamping elements tending to rotate about the fulcrum point provides two closely adjacent points of application of pressure against the guide rail to prevent movement of the clamping device in either the upward or downward direction. The coaction between the clamping elements and the bolt also provides force applying means in contact with the core and coil assembly and locking means for the bolt to prevent accidental or inadvertent loosening thereof.

.Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that changesand modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

l. A clamping device for restraining an object against movement comprising the combination of a fixed guide rail and means including a bolt, a first clamping element, and a second clamping element, each of said elements having first and second ends and a contact surface, one of said elements having its said contact surface formed intermediate its said ends to define a fulcrum line engageable with the said contact surface of the other of said elements for relative pivoting of said elements, said rail and said elements consisting of resilient material, the first end of each of said elements closely surrounding said rail, said elements abutting intermediate their ends at said contact surfaces, said bolt passing through an opening in the second end of said first element and threadedly received into the second end of saidsecond element, said means being movable along said rail so that said bolt can make contact with said object, said bolt being adjustable with respect to said elements to move said secondends of "said elements toward each other with the head of said bolt engaging a thrust surface of said first element, thereby relatively pivoting said eleabout said fulcrum line until said first ends of said elements jam against said rail, bolt then abutting said object and when adjusted coacting through said elements with said rail so that the resilience of said elements and of said rail causes a thrust on said object and prevents loosening of said means with respect to said rail.

2. A clamping device for restraining an object from moving comprising a fixed guide rail having a T-shaped cross section, force applying means, a "rst clamping element, and a second clamping element, said rail and said elements consisting of resilient material, each of said elementshaving first and second ends and a contact surface, one of said elements having its said contact surface formed intermediate its said ends to deiine a fulcrum line engaging the said contact surface of the other of said elements for relative pivoting of said elements, the first end of each of said elements having a T-shaped slot slightly larger than the cross section of said rail, said rail re ceived in the slots of said element with said elements movable along said rail, said means connected to the second ends of said elements and being engageable With saidlobjectrsaid means coasting with said elements and adjustable with respect to said elements to force said second ends toward each other for relatively pivotingsaid elements about said fulcrum line to thereby jam said first endson said rail, said means abutting said object and when adjusted coacting through said elements with said rail so that the resilience of said elements and of said rail causes a thrust on said object.

against movement, said device comprising a fixed guide rail, an adjustable force applying means, and a pair of clamping elements having first and second ends, said rail and said elements consis"- ing of resilient material, said first ends of said elements substantially enclosing said rail, each of said elements having first and second ends and a contact surface, one of said elements having its said contact surface formed to define a fulcrum line engageable with said contact surface of the other of said elements, said force applying means adjusted to act on said second ends to bring them toward each other, said elements in contact with each other along said fulcrum line intermediate said force applying means and said rail, said force 3. A clamping device for restraining an object FRANK J. SURENDA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Anderson July 21, 1931 Number