US2022825A - Drawing board clamp - Google Patents

Description

Patented Dec. 3, 1935 UNITED STATES PATENT o-FFlcE 15 Claims.

This invention relates in general to a drawing board. clamp, and more particularly has reference. to a means adapted to be attached to a drawing board for the purpose of securing thereto in operative position a sheet of drawing paper or similar material.

Under ordinary circumstances, drawing paper or the like is secured to drawing boards by means of thumb tacks projected through the drawing paper and into the drawing board itself. This means is commonly known to be unsatisfactory for numerous reasons, chief among these being that the thumb tacks mutilate both the drawing and the drawing board, that the thumb tacks easily become lost and are a source of constant expense, that they obstruct free access to the drawing paper, and that it is a relatively. slow and difficult thing to position a sheet of drawing. paper and secure it accurately in place on a drawing board by means of thumb tacks.

Many attempts have been made to produce means by which a drawing might be more advantageously secured to a drawing board than by means of thumb tacks. However, such attempts have generally resulted in failure either because of the complicatednature of the devices developed and the expense and likelihood of breakage or because the devices have not been capable of performing the desired functions.

It is therefore an object of this invention to produce a device for the purpose set forth which can be made a part of the drawing board itself and will not mutilate either the drawing or the drawing board in any way whatsoever.

It is a further object of this invention to provide a device of the type set forth which will be" simple in construction and operation relatively cheap to manufacture, and at the same time sturdy enough to meet every ordinary demand which might be placed upon it.

Still another object of this invention is to provide a device with which it will be possible to clamp asheet of drawing paper or the like to a drawing board in any position desired by the simple expedient of manipulating the end of a controlling device to release the clamp, properly: positioning the sheet of drawing, and releasing the control mechanism to allow the clamping means to engage the sheet.

With the above and other objects in View,

this invention embodies the several parts and combinations thereof as set forth by way of illustration and example in the accompanying drawing and the following description,- andas claimed in; the appended claims.

Referring now more particularly to the drawing in which like numerals indicate correspond" ing parts throughout:

Figure 1- is a top plan view of a device embodying this invention showing the same in place on a drawing board.

Figure 2 is a longitudinal vertical section showing the device in open or unclamped posi tion.

Figure 3 is a transverse vertical sectional View taken along the line 3-3 of Figure 2.

Figure 4 is a longitudinal vertical section taken along the line 4-4 of Figure 5 and showingthe device in closed or clamped position.

Figure 5 is a transverse vertical sectional view taken along the line 55 of Figure 4;

Figure 6 is a perspective, with parts broken away, showing the lower clamping member.

Figure 71s a similar view showing in inverted position a portion of the upper clamping member.

Figure 8 is a similar view showing the latching rod for drawing the two clamping members together in the clamping operation.

As illustrated in the drawing, the clamp is adapted to be positioned along an edge of a drawing board I or the like for the purpose of clamping the edge of a drawing paper 2 in the proper position upon the drawing board; It is to be understood that the term drawing paper as used in this specification and inthe appended claims is not to be strictly construed, but is to be considered of such scope as to include not only drawing paper, but other materials of similar nature which are or may be used upon a drawing board for drawing purposes.

Referring especially to Figures 3 and 5, it will be seen that the drawing board clamp illustrated consists generally of a lower stationary clamping member generally indicated .at 3, an upper movable clamping member generally indicated at 4, and a latching 'rod generally indicated at 5 in Figures 2 and 4; The lower clamping member 3 is shown-as being of substantially channelshaped cross section having a lower intermediate portion 6, and upstanding side portions 1 and 8: The intermediate portion 6 is provided with a plurality. of spaced openings for the purpose of receiving screws 9 or the like by which this member is firm- 1y anchored to the drawing board. Projecting upwardly from the intermediate portion-Gare a plurality of'spaced upstanding guide ears l0 having aligned guide openings 1 I therethrough for a purpose presently to be described. One of these openings in one-of the ears I0 is of square or other two parts and is of substantially inverted channel between and be spaced from the ears i0.

non circular form as indicated at I2 in Figure 6.

The upstanding side portion 1 is positioned next to the body of the drawing board I, and has its upper edge inwardly turned at l3 to provide an upwardly facing clamping surface l4. This surface may be serrated as shown in Figure 6 so as to more efficiently perform its clamping function. The member 3 is so positioned with respect to the drawing board that the clamping surface [4 is substantially on a level with the operative surface of the drawing board so that when a drawing paper is clamped against this surface [4, it will extend therefrom directly onto the drawing board.

The upstanding side portion 8 is provided with ears l5. which are turned inwardly and extend toward the opposite side portion 7. These ears are each formed with an opening 16 so as to make a part of a hinge structure for a purpose to be presently described. This side portion 8 is also provided with horizontally disposed bracing members ll which are notched and positioned to receive portions of the edges of certain of. the upstanding guide ears It so as to maintain these ears in their proper upstanding position at all times. 1

The member 3 is preferably formed of sheet metal of similar material and the various ears, bracing members, etc. are formed of stamped out integral portions of the same. As will be readily seen from the drawing, this will make it possible to form such a member of a single piece of such sheet metal by simple stamping and bending operations, thus contributing to the simplicity of the structure and lowering the cost of manufacture.

The upper clamping member 4 is formed of shaped cross section with the exception of a laterally extending portion providing the clamping surface. This member has as its principal part a channel shaped section generally indicated at it and consisting of an upper intermediate part 59 and downwardly extending side parts 20 and 2!. The side part 2i is positioned adjacent the upstanding side part 8 of .the lower clamping member, and is notched at 22 to provide tabs or lugs 23 so positioned as to engage in the openings 16 in the ears [5 on the lower member and thus provide for hinging the two members together. The side part 26 is adapted to extend downwardly past the inner edge of the lower clamping surface l4 and form a stop for a sheet of drawing paper or the like to cause the same to line-up with the board and to prevent it from coming in contact with the operating portions of the drawing board clamp. The intermediate part I9 is provided with a plurality of downwardly extending ears 24 which aresimilar to the previously described ears 5 6, and which are provided with aligned openings 25 therethrough. These cars 24 are so positioned that when the parts are assembled they will lie Like the lower channel shaped member, this upper member just described is preferably formed of a sheet metal and the ears 24 are stamped out from Where it'passes through the other ears.

shaped member l8 into overlying opposed relation with respect to the clamping surface 14. Thus the lower surface of this laterally extending edge part 21 forms an upper clamping surface adapted to cooperate with the lower clamp- 5' ing surface I l in clamping paper on the draw ing board. The upper surface of the sheet 26 may be provided with suitable indicia such as for instance a scale such as a draftsman might need and such as is indicated at 28, and a set of letters 29.

For the purpose of moving the clamping mernbers 3 and 4 toward and from each other, there is provided a slidable latching means which will. now be described. A rod 30 is provided and fitted 15 through the openings II, I 2 and 25 in the respective ears l9 and 24 as illustrated in Figures 2 and 4. Those portions of the rod 30 which engage the openings 25 in the ears 24 are inclined with respect to the general direction of the rod 20 This is clearly shown at 3!. For the purpose of preventing the rod from turning on its own axis and thus permitting the member 4 to move to unclamped position, the end portion 32 of the rod is formed 25 with a square or noncircular cross section corresponding to the shape of the opening I2 through which it passes.

It will readily be seen that sliding the rod to the left as seen in Figures 2 and 4 will cause the 30 upper member 4 to be drawn into clamping position while movement to the right will cause it to move to unclamped position An opening 33 is provided in the squared end of the rod for the purpose of receiving a cotter pin 34 and limiting 35 the extent of movement of the rod to the left. Surrounding the opposite end of the rod is a coil spring 35 bearing against the car H] which is nearest the left end of the device. The opposite end of this spring bears against a washer 36 which is in turn held in place on the rod 30 by means of a cotter pin 31 inserted'through an opening 38 provided in the rod for that purpose. The extreme end of the rod is threaded asat 39 and is provided with a ring shaped fitting 40. This fitting 40 is preferably positioned in a cutout portion 4| in the edge of the drawing board, and is adapted to be grasped by the operator in moving the rod 30.

It will be seen from the above that the rod 30 is normally urged to the left by means of the spring 35 so as to tend to force the clamping sure faces to approach each other. However, it is a simple matter for the operator to grasp the ring 40 and force the rod in the opposite direction 5- to move the movable clamping member 4 about its hinge connection to separate the clamping surfaces and release or insert a sheet of drawing paper as the case may be. Upon being released the rod will be automatically urged to the left by the spring 35 and the clamping surfaces will be caused to approach each other.

It is evident that in the embodiment illustrated a means has been provided which is fully capable of carrying out all of the objects and advantages sought for and claimed in connection with this invention. The simplicity both of construction and the operation of this invention together with its efiiciency and the certainty with which it functions may be easily seen. The cost of manufacture on the other hand is such as to permit its use under conditions where a more expensive device would be prohibited.

It will be appreciated that various changes and modifications may be made in the embodiment of the invention as shown and described without departing from the spirit of the invention or the scope of the appended claims. The'embodiment shown and described is therefore to be taken by way of illustration and example only and is not to be construed by way of limitation.

Having described my invention, I claim:

1. In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, means movable with respect to said movable clamping member for moving said movable clamping member to cause said clamping surfaces to approach each other and clamp a drawing paper therebetween, and means resiliently urging said first mentionedmeans in a direction to bring said clamping surfaces together.

2. In a drawing boardclamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, means movable with respect to said movable clamping member for moving said movable clamping member to cause said clamping surfaces to approach each other, and clamp a drawing paper therebetween, resilient means urging said first mentioned means in a direction to bring said clamping surfaces together, and. means adapted to be engaged by the hand of an operator to move said first mentioned means in the opposite direction.

3. In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, cooperating guides on the adjacent sides of said stationary and movable clamping members respectively, and slidable latching means disposed in said guides, said latching means having wedge-like portions engaging the guides on one of said clamping members, whereby movement of said latching means in one direction through said guides will draw said clamping members toward each other.

4. In a drawing board clamp, a lower stationary clamping member having a clamping surface thereonadapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, cooperatingguides on the adjacent sides of. said stationary and movable clamping members respectively, slidable latching means disposed in said guides, said latching means having wedge-like portions engaging the guides on one of said clamping members, whereby movement of said latching means in one direction through i said guides will draw said clamping members toward each other, .andspring means for continuously urging said latching means in said one direction.

I 5."In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, a plurality of ears on each of said clamping members extending toward the other clamping member, said ears each having a guide opening therein, and a slidable latching rod passing through the guide openings of said respective ears, said rod having its portions in engagement with the ears on one of said clamping members disposed at an angle to its portions in engagement with the ears on the other clamping member, whereby movement of said latching rodin one direction through said guide openings will draw said clamping members toward each other.

6. In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, a plurality of ears on each of said clamping members extending toward the other clamping member, said ears each having a guide opening therein, and a slidable latching rod passing through the guide openings of the respective ears, said rod having its portions in engagement with the ears on one of said clamping members disposed at an angle to its portions in engagement with the ears on the other clamping clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, a plurality of ears on each of said clamping members extending toward the other clamping member, said ears each having a guide opening therein, a slidable latching rod 2 passing through the guide openings of said respective ears, said rod having its portions in engagement with the ears on one of said clamping members disposed at an angle to its portions in engagement with the ears on the other clamping member, whereby movement of said latching rod in one direction through said guide openings will draw said clamping members toward each other, and a spring on said latching rod for continuously urging same in said one direction.

8; In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface 'of a drawing board, an upper movable clamping member movably mounted'above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, a plurality of ears on each of said clamping members extending toward the other clamping member, said ears each having a guide opening therein, a slidable latching rod passing through the guide openings of said respective ears, said rod having its portions in engagement with the ears on one of said clamping members disposed at an angle to its portions in engagement with the ears on the other clamping member, whereby movement of said latching rod in one direction through said guide openings will draw said clamping members toward each other, and a spring on said latching rod for continuously urging same in'said one direction, said latching rod having a part projecting from between said clamping members and adapted to be engaged by the hand of an operator to move said latching rod in the opposite direction against the action of. said spring.

9. In a drawing board clamp, a lower stationary clamping member of substantially channel shaped cross section having one of its edges inturned to form an upwardly facing clamping sur-,

face adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member movably mounted above said stationary clamping member and having a downwardly facing clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, and means for moving said movable clamping member to cause said clamping surfaces to approach each other and clamp a drawing paper therebetween.

10. In a drawing board clamp, a lower stationary clamping member of substantially channel shaped cross section having one of its edges inturned to form an upwardly facing clamping surface adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member of inverted channel shaped cross section movably mounted above and adapted to fit within said stationary clamping member, said movable clamping member including a plate secured to the upper surface of said part of channel shaped crosssection and having a laterally projecting part providing a downwardly facing clamping surface in overlying opposed relation to said clamping surface on the stationary clamping member, and means, for moving said movable "clamping member to cause said clamping surfaces to approach each other.

11. In a drawing board clamp, a lower stationary clamping member of substantially channel shaped cross sectionhaving one of its edges inturned to form an upwardly facing clamping surface adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member of inverted channel shaped cross section movably mounted above and adapted to fit within said stationary clamping memher, said movable clamping member including a plate secured to the upper surface of saidpart of channel shaped cross section and having a laterally projecting part providing a downwardly facing clamping surface in overlying opposed relation to said clamping surface on the stationary clamping member, and means for moving said movable clamping member to cause said clamping surfaces'to approach each other, said channel shaped members having their edges opposite said clamping surfaces formed withintegral inter:

engaging hinge portions for 'hingedly connecting said members together.

12. In a drawing board clamp, a lower .stationary clamping member of substantially channel shaped cross section having one of its edges inturned to form an upwardly facing clamping surface adapted to be positioned on a level with V the surface of a drawing board, an upper movable clamping member of inverted channel shaped cross section movably mounted above and adapted to fit within said stationary clamping member, said movable clampingmember including a plate secured to the upper surface of said part of channel shaped cross section and having a laterally projecting part providing a downwardly facing clamping surface in overlying op-' posed relation to saidclamping surface on the stationary clamping member, and a means for moving said movable clamping member to cause said clamping surfaces to approach each other, said channel shaped members being hinged together along their edges opposite said clamping surfaces. r

13. In a drawing board clamp, a lower stationary clamping member having a clamping surface thereon adapted to be positioned on a level with the surface of a drawing board, an upper movable clamping member hingedly mounted above said stationary clamping member and having a clamping surface thereon in overlying opposed relation to said clamping surface on the stationary clamping member, and resilient means for continuously urging said movable clamping member about its hinge mounting to cause said clamping surfaces to approach each other, 3

14. In a drawing board clamp, a lower stationary clamping member'of substantially ,channel shaped cross section having one of its edges intumed to form'an upwardly facing clamping surface adapted to be positioned on a level with 40 the surface of a drawing board, an upper movable clamping member of inverted channel shaped cross section movably mounted above and adapted to fit within said stationary clamping member, said movable clamping member including a -15 plate secured to the upper surface of said part of channel shaped cross section and having alaterally projecting part providing a downwardly facing clamping surface in overlying opposed relation to said clamping surface on the stationary clamping member, a plurality of integral ears stamped out of the intermediate portions of each of said channel shaped members and extending toward the other clamping member, said ears each having a guide opening therein, and a slidable latching rod passing through the guide openings of said respective'ears, said rod having its portions in engagement with the ears on one of said clamping members disposed at an angle to its portions inlengagement with the ears on the other clamping member, whereby movement of said latching rod in one direction through said guide openings will draw said clamping members toward each other. 7

15. In a drawing board clamp, a lower stationary clamping member of substantially channel shaped cross section having one of its edges inturned to form an upwardly facing clamping surface adapted to be positioned on a level with the surfaceof a drawing board, an upper movable clamping member of inverted channel shaped cross section movably mounted above and adapted to fit within said stationary clamping member, said movable clamping member including a plate secured to the uppersurface of said 7 ears on one of said clamping members disposed at an angle to its portions in engagement with the ears on the other clamping member, whereby movement of said latching rod in one direction through said guide openings will draw said 5 clamping members toward each other, and portions struck out from a. side of one of said channel shaped members forming braces for the adjacent ears on the same channel shaped member to hold said ears in proper position.

ARTHUR J. ROMEIS.

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