US1359452A - Scaffold - Google Patents

Description

H. WALKER.

SCAFFOLD. APPLICATION FILED FEB. 19, 1920.

IhnnnedBbv.16,1920.

2 SHEETSSHEET I.

Wi t wean H. WALKER.

SCAFFOLD.

APPLICATION FILED FEB. 19, 1920- 1,359,452. Patented Nov. :16, 1920.

2 SHEETS-SHEET 2.

VII/11,55 I

UN [T E STATES PAT E NT OFFI C HOWA BD I. WALKER, OF CGLUMBUS, OHIO.

SC AFFOLD.

Application filed February 19, 1920. Serial No. 359,796,

T all whom itmcn concern.

Be it known that I, l-lowARnI. lVALKnR, a citizen o1 the United States, residing at; Columbus, in the county oi: Franklin and State of Ohio, have invented certainnew and useful Improvements in Scaffolds, of which the following is a specification.

This invention relates to improvements in adjustable scaffolds and has for its primary object to provide a scaffold wherein an ellicient and readily operated clamping structure is provided for the purpose of retaining the horizontal cross members of the scaffold in adjustably secured relationship with the upright side members, the arrangement being such that the horizontal cross members may be caused to assume any desired vertical position of adjustment, best adapted to the particular need at hand, and to render the operation of the clamping; structure reliable and positive so that loss of adjustment will be prevented.

Another object of the invention resides in the provision of a scaffold of the character stated wherein the clamping structure is formed to include an angular bracket, the latter being; formed with portions extending parallel with the vertical and horizontal members of the scaiiold, said bracket being further provided with slidably mounted cleats which are adapted to be pressed into engagement with the side edges of both the horizontal and vertical members or? the scarfold by means of pivoted cam levers, the arrangement being such as to provide for an exceptionally positive yet easily actuated clamping structure, which will effectively serve to prevent undue movement between the related parts.

For a further understanding of the invention, reference is to be had to the following description and t0 the accompanying; drawing, in which similar characters of ref:- erence denote like and corresponding); parts throughout the several views thereof. In said drawing:

Figure 1 is a side elevation of ascaffold constructed in accordance with the principles of the invention,

Fig. 2 is a top plan view thereof,

Fig. 3 is a detail horizontalsectional view disclosing on an enlarged scale the construction ofthe clamping structure,

F 1g, 4 1s, a similarview disclosing the parts in vertical cross section, V

F 1g. 51s a side elevation of the clamping structure and its associated parts,

Fig. 6 is a detail horizontal'sectional view disclosing the mounting for one ofthecam levers, v

F 1g. 7 is a side elevation of a slightly modified form of clamping structure, and i Fig. 8 1s a horizontal sectional view taken therethrough on the line 8-8 ofFig. 7.

In the accompanying drawings there is shown a ladder or scaffold structure 1 which preferably consists of a pair or vertically extending side members 2 and an intervenlng horizontally extending member 3. This latter member may be of any desired construction, but as shown in Fig. 2 the same may consist of two parts, each of which parts is formed to embody a plurality of spaced fingers which are adapted to telescopically extend within complemental spaces provided between the iingers'of the adjacent part. By means of this construction the member 3 is rendered extensible so that the side members 2 may be placed apart any suitable distance within the range of adj ustment of the member 3. Primarily, the present invention consists in the provision of an improved clamping structure 4' which is adapted to be utilized for the purpose of adjustably connecting the member 3 with the side members 2 and to thereby enable said horizontal member to be retained in any desired position of vertical adjustment in order thatthe ladder or scafiold may be best adapted to the work at hand.

In the preferred form of the present invention, the clamping structure consists of a pair o1": brackets 5, which brackets are disposed adjacent to the outer ends of the horizontal member 3 and to be thereby ca pable of connectingthe member 3 with the vertical side members 2. Each of the brackets consists of horizontally extending arms 6 and vertically extending arms 7, the arms 6 being arranged to extend parallel with the underside of the horizontal membe1'-3,while the arms 7 are similarly arranged to extend parallel with the inner face of one of the side members 2. The horizontal arms 6 connected their outer ends by means of a horizontally disposed transversely tending bar 8 and by means of second similarly extending bar 9, which is disposed intermediately oi the length of the 6. The vertical arms 7 are similarly joined by means of transversely disposed bars 10 which are adapted to lie COHtl tlOllS to the inner face of the side member 2. As shown in Fig. 3, the bars 10 have one ojt their ends bent as at 11 to provide fingers which are adapted to engage with the cooperative side edge of the member 2. The opposite ends of the bars 10 project appreciably beyond the opposite side edge of the member .2 and, as shown in 6, are adapted to receive a pair of slidable cleats Thesccleats are formed to embody slotted ions 13 which extend parallel and in gageinent with the cooperative ends of the l0, and said cleats terminate in right angularly bent fingers 14, which engage with the ad jacent side edges of the m inber 2. Further, the bars 10 are provided with bolts 15, whose shanks:protrude through theslots 13 formed in the cleats 12 and are connected with the body portions of pair of cam levers 16, the construction being such that the cam lovers are permit ed to revolve upon the ends of the bolt shanks. Nuts 17 may be provided for the purpose retaining the cam lovers in their operative positions by preventing dislocation of: the bolts 15. The cam levers, shown in 4:, are so formed that their eccentric surfaces 18 will be positioned so as to engagewith the fingers 1e 01' the cleats 1: 3, whereby upon the'rotation of said cam levers in a specified direction, said cleats 12 will be moved inwardly into frictional relationship with the cooperative side edge of the side memher 2. The levers 16 are preferably provided with extended handle portions 19, by means of which considerable pressure may be applied to the cleats 12 for the purpose ofmaintaining the adjustment of the ladder. It will thus be manifest that the rotation of the cam levers will result in frictionally connecting the brackets 5 in any desired position of adjustment in connection with the s e members 2, thereby controlling the VBEtlCYtl working positions of the horizontal cross member Through the provision of the cam levers this adjustmay be quickly obtained and o offectively prevented from slipping when weight is to be carried tl iereby. A set screw 20 may be employed ii desired'i or friction ally bending the lower bar 10 in secured engagement with one of the cciipera ive side members 2, the adjustment or the set screw 20 being supplemental to the main adjusteach bracket is formed after the fashion of the bars 10. That is, the bar 9 is formed to provide a portion 21 at one o'liits ends, which portion adapted to engage with the cooperative side edge of the memher 3. To maintain this relationship, the other end of the bar 9 is extended so as to project beyond the adjacent side edge of the member h slidable cleat 22 is then connected with this projecting end by means of a belt or its equivalent 'lhis bolt serves as a pivot for a cam lever 24 which, when oscillated, will cause the cleat 22 to be firmly pressed into engagement with the cooperative edge of the horizontal member 3, thus securely uniting both of the ends of the bar 9' in conjunction with said horizontal member. Also, a so screw 25 is adapted to pass centrally through the bar 9 and to engage with the underside of the member 3, said set screw further serving to establish a rigid connection between the bracket and the horizontal member.

The outer bar 8 01" each of the brackets is formed so that both of its ends will project beyond the side edges of the member 3, and to these outwardly projecting ends a pair of hook bolts 26 is connected; Those bolts are so formed that their upper hooked ets.

From the fore oino descri ition taken in a I n b L) I COl1]11IlCtlOIl with the accompanying drawings, it will be seen that the present invention provides a scaffold, adder or other similar structure wherein an improved cennec tion exists between the side horizontal members thereof, the connection being such as to allow for relative adjustment between said members and to maint n the adir ment after the same has been ally ei'fe it will of course be apparent that the cm. lever 16 could be so formed as to impinge directly upon the side edges of the members 2 and However, the slidine cleats are preterably employed to prevent the clamping action of the cam levers from'damaging or mutilating the cooperative portions of said members, and to enable the cam levers to exercise a firm and positive grip upon the edges oi said members. The construction enables the horizontal member 3 to be set at any'desired vertical position of operation, and also enables the scaffold structure as a whole to be readily collapsed and stored in but a minimum of space. As above stated, the invention is particularly directed to the clamping structure, and hence the ladder may be employed in any capacity where adjustment is desired between right angular-1y disposed members.

in Figs. 7 and 8 a slightly modified form of clamping structure has been disclosed. As shown, this modified form is adapted to be employed in connection with a vertical side member 29 and with a relatively adj ustable horizontally extending member 30. The clamping structure consists of a laterally separable bracket 31. This bracket, therefore, embodies a horizontal bar 32, which is suitably secured to the under surface of the member 30. To the outer ends of this bar there is pivotally secured a pair of bracket arms 33, which latter are provided with horizontal and vertical extending portions 34 and 35 respectively, which are adapted to occupy the corners caused by the meeting of the members 29 and30. The arms 35 are provided with fined horizontally extending bars 36. which have their outer ends formed to provide fingers 37, the latter leing disposed to engage with the side edges of the vertical member 29. The inner ends of the bars 36 are connected with opposed angle members 38 and 39, and by this construction it will be manifest that the members 38 and 39 will be caused to swing outwardly or inwardly in unison with the bracket arms,

the inward movement of the bracket arms being limited by the engagement of the fingers 37 with the edges of the vertical member 29, and also by the relative engagement with the angle members 38 and 39. To look the parts in their applied positions, the angle member 38 is provided with a lug 40, which passes through an opening 41 formed in the angle member 39. The lug is in turn equipped with an opening 42 through which a set screw 43 is arranged to pass, the latter being also threaded through a suitable opening 44 formed in the member 39, and the inner end of the screw is adapted to impinge against the inner surface of the side member By the presence of the set screw 43 it will. be manifest that the bracket arms will be retained against separation, hence the fingers 37 will be maintained in their clamping positions upon the side edges of the member 29 and further, the set screw also serves on its own behalf in preventing vertical slipping movement on the part of the bracket structure. Also, the angle member 38 may be provided with other lugs 45 which are disposed beneath the lug 40 and are arranged to pass through cooperative openings formed in the member 39 when the bracket arms are closed. A head pin is adapted to be utilized in preventing the separation of the angle members 33 and 39 by passing through openings formed in the lugs l5. The pin l6 therefore acts in the supplemental capacity to the set screw 43 and prevents undue separation of the lower ends of the angle members.

What is claimed is:

1. In a connection of the class described, the combination with a vertical side member and an angularly extending adjustable horizontal member, of a clamping structure for uniting said members, comprising a bracket arranged to fit within the corner defined by the meeting of the side and horizontal members, extensions formed upon the vertical portions of said brackets, cam levers carried by said extensions and arranged to engage with the side edges of said vertical member to maintain the positions of adjustment of said bracket, and means carried by the horizontal portion of said bracket for similarly clamping said horizontal member thereto.

2. In a connection of the class described, the combination with a vertical side member and an singularly extending horizontal member, of a clamping structure for adjustably connecting said horizontal member with said side or vertical member, comprising a bracket having portions extending parallel with said members, projections formed upon the vertical portions of said bracket, cleats slidably carried by said projections, and cam levers pivotally connected with said projections and capable of urging said cleats into holding engagement with said side member, and means connected with the horizontal portions of said bracket for similarly connecting said horizontal member thereto.

3. In a structure of the class described, the combination with a vertical side member and an angularly extending adjustable horizontal member, of a clamping structure for adjustably connecting said horizontal member to said side member, said clamping structure comprising a bracket formed to include portions extending parallel with said side and horizontal members, clamping means carried by said side portions and arranged to be frictionally maintained in engagement with the edges of the side member, and cooperative means for connecting the horizontal portions of said brackets to said horizontal member.

4. In a structure of the class described, the combination with vertically extending member and an adjustable horizontal member, of a clamping structure for adjustably connecting said horizontal member to said vertical member, comprising a bracket having portions disposed to extend in parallelism with said members, the vertical portion of said bracket being provided With rigid clamping fingers arranged to receive one of the edges of said vertical member, adjustable cleats carried by the edge of said bracket 01)- posite to said fingers cam levers operable to press said cleats into engagement With the edges of said vertical member and to thereby bind said fingers into similarly operative engagement, and means carried by the horizontal portions of said bracket to similarly 'en gage and secure said horizontal member in connection With the bracket.

In testimony whereof I affix my signature.

HOWARD I. WALKER.

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