| Fig. | | Page. |
|---|
| [1]. | Early Type of Mechanical Cleaning Nozzle Using Compressed Air | 6 |
| [2]. | Another Type of Compressed Air Cleaning Nozzle, Supplemented with Vacuum Pipe | 8 |
| [3]. | Separators Used With Combined Compressed Air and Vacuum Machines | 9 |
| [4]. | Piston Type of Vacuum Pump, Mounted Tandem With Air Compressor | 9 |
| [5]. | Mr. Kenney’s First Renovators Vacuum Alone Being Used as Cleaning Agent | 10 |
| [6]. | Air Compressors Arranged for Operation as Vacuum Pumps | 11 |
| [7]. | Separators Installed by Mr. Kenney in Frick Building | 12 |
| [8]. | Vacuum Renovator With Inrush Slot, Introduced by the Sanitary Devices Manufacturing Company | 13 |
| [9]. | First Portable Vacuum Cleaner, Constructed by Dr. William Noe, of San Francisco, in 1905 | 16 |
| [10]. | Late Type of Spencer Vacuum Cleaning Machine, Operated by Multi-Stage Turbine Blowers | 17 |
| [11]. | Type A, the Straight Vacuum Tool | 26 |
| [12]. | Type B, with Wide Slot and Wide Bearing Surface | 26 |
| [13]. | Type C, with Auxiliary Slot, Open to Atmosphere | 28 |
| [14]. | Type D, with Two Cleaning Slots | 28 |
| [15]. | Type E, with Inrush Slot on Each Side of Vacuum Slot | 31 |
| [16]. | Type F, an Exaggerated Form of Type B | 31 |
| [17]. | Tests of Three Renovators on Dirty Carpets | 35 |
| [18]. | Cleaning Tests of Carpets Filled with Quicksand | 39 |
| [19]. | Cleaning Tests Using 1 oz. of Sand Per Square Yard of Carpet | 41 |
| [20]. | Three Series of Tests with Kenney Type A Renovators | 45 |
| [21]. | Tests by Mr. Reeve, Using Type C Renovator | 46 |
| [22]. | Tests by Mr. Reeve, Using Type D Renovator | 47 |
| [23]. | Tests Showing Efficiency of Different Types of Renovators at Different Degrees of Vacuum | 50 |
| [24]. | Early Type of Bare Floor Renovator | 55 |
| [25]. | Later Type of Bare Floor Renovator | 55 |
| [26]. | Another Type of Bare Floor Renovator | 56 |
| [27]. | Bare Floor Renovator with Felt Cleaning Surface | 57 |
| [28]. | Bare Floor Renovator with Unusual Form of Slot | 58 |
| [29]. | Bare Floor Renovator with Hard Felt or Composition Rubber Strips | 58 |
| [30]. | Bare Floor Renovator with Rounded Wearing Surface | 59 |
| [30a]. | The Tuec School Tool | 62 |
| [31]. | Round Bristle Brush for Carved or Other Relief Work | 62 |
| [32]. | Rubber-Tipped Corner Cleaner for Use on Carved or Other Relief Work | 62 |
| [33]. | Early Type of Upholstery Renovator | 63 |
| [34]. | Upholstery Renovator with Narrow Slots to Prevent Damage to Furniture | 64 |
| [35]. | Another Type of Upholstery Renovator with Short Slots | 65 |
| [36]. | Hand Brush Type of Renovator | 65 |
| [37]. | Form of Swivel Joint Connecting Stem to Renovator | 72 |
| [38]. | Swivel Joint Arranged to Prevent Dust Lodging Between the Wearing Surfaces | 73 |
| [39]. | Swivel Joint in Use | 74 |
| [40]. | Another Use of Swivel Joint, Showing Possibilities of this Form | 75 |
| [41]. | Operator Cleaning Trim of Door with Swivel Joint | 76 |
| [42]. | Swivel Joint, with Screwed Union | 76 |
| [43]. | Swivel Joint Having Ball Bearings | 76 |
| [44]. | Action of Ball-Bearing Swivel Joint | 77 |
| [45]. | Illustration of Defects of Plug Cocks | 78 |
| [46]. | Bayonet Type of Hose Coupling, Introduced by the American Air Cleaning Company | 82 |
| [47]. | All Rubber Hose Coupling Used by the Spencer Turbine Cleaner Company | 83 |
| [48]. | Chart for Determining Hose Friction | 86 |
| [49]. | Effect of Increase of Velocity on the Friction Loss | 88 |
| [50]. | Another Test Showing Friction Loss Due to Velocity | 89 |
| [51]. | Inlet Cock to Prevent Air Leakage when Not in Use | 101 |
| [52]. | Type of Automatic Self-Closing Inlet Cock | 102 |
| [53]. | “Smooth Bore” Pipe Coupling | 103 |
| [54]. | Joint Made of Standard Pipe Flanges | 104 |
| [55]. | Standard Durham Recessed Drainage Fittings Generally Used in Vacuum Cleaning Installations | 105 |
| [56]. | Friction Loss in Pipe Lines | 106 |
| [57-60]. | Diagrams Showing Operation of Brush and Carpet Renovators Under Different Conditions | 110 |
| [61]. | Typical Floor Plan of Office Building Illustrating Number of Sweepers Required | 114 |
| [62]. | Plan of Layout for Office Building Showing Best Location (at d) for Vacuum Producer | 118 |
| [63]. | Vacuum Cleaning Layout for a Passenger Car Storage Yard | 122 |
| [64]. | Arrangement of Piping Recommended as Best for Passenger Car Storage Yard | 123 |
| [65]. | Good Location for Dust Separator Where Large Areas Are Served by One Cleaning System | 125 |
| [66]. | Location of Separators at Centers of Groups of Risers for Large
Systems | 126 |
| [67]. | Early Type of Primary Separator, Used by Vacuum Cleaner Company | 128 |
| [68]. | Primary Separator Used by the Sanitary Devices Manufacturing Company | 128 |
| [69]. | Primary Separator Used by the General Compressed Air and Vacuum Cleaning Company | 129 |
| [70]. | Primary Separator Made by the Blaisdell Engineering Co. | 129 |
| [71]. | Secondary Separator Used by the Vacuum Cleaner Company | 131 |
| [72]. | Secondary Separator Used by the General Compressed Air and Vacuum Cleaning Company | 131 |
| [73]. | Secondary Separator Used by the Sanitary Devices Manufacturing Company | 132 |
| [74]. | Type of Dry Separator Used as Secondary Separator | 134 |
| [75]. | Form of Complete Separator Used by the Vacuum Cleaner Company | 135 |
| [76]. | Complete Separator Brought Out by the Electric Renovator Manufacturing Company | 136 |
| [77]. | Complete Separator Made by the American Radiator Company | 137 |
| [77a]. | Interior Construction of Dunn Vacuum Cleaning Machine | 140 |
| [78]. | Power Consumption and Efficiency of Air Compressor Used as a Vacuum Pump | 143 |
| [79]. | Modification of Reciprocating Pump Made by the Sanitary Devices Manufacturing Company | 144 |
| [80]. | Power Consumption and Efficiency of Modified Reciprocating Pump | 145 |
| [81] and [82]. | Indicator Cards for Clayton and Modified Pumps | 146 |
| [83]. | One of the Pumps Installed in Connection with the Vacuum Cleaning System in the New York
Post Office, the Largest Reciprocating Pump Used for this Purpose up to the Present | 148 |
| [84]. | Interior Arrangement of the Garden City Rotary Pump | 149 |
| [85]. | Power Required to Operate Garden City Type of Rotary Pump | 150 |
| [86]. | Arrangement of Double-Impeller Root Type Rotary Pump for Vacuum Cleaning Work | 151 |
| [87]. | Rotary Pump Arranged with Double-Throw Switch for Reversing Pump | 152 |
| [88]. | Power Consumption and Efficiency of Root Type of Pump | 153 |
| [89]. | The Rotrex Vacuum Pump, Used by the Vacuum Engineering Company | 153 |
| [90]. | Late Type of Centrifugal Exhauster Made by the Spencer Turbine Cleaner Company | 154 |
| [91]. | Power and Efficiency Curves for the Spencer Machine | 155 |
| [92]. | Interior Arrangement of Invincible Machine, Manufactured by the Electric Renovator
Manufacturing Company | 156 |
| [93]. | Power Consumption, Vacuum and Efficiency of First Types of Invincible Machine | 157 |
| [94]. | Power Consumption, Vacuum and Efficiency of Invincible Machine After Valve Was Fitted to Discharge | 158 |
| [95]. | Four-Sweeper Invincible Plant Installed in the United States Post Office at Los Angeles, Cal. | 159 |
| [96]. | Centrifugal Pump with Single Impeller, Manufactured by The United Electric Company | 161 |
| [96a]. | Test of Centrifugal Pump with Single Impeller | 162 |
| [97]. | Steam Aspirator Used by the American Air Cleaning Company | 163 |
| [98]. | Steam Consumption of Steam Aspirator | 164 |
| [99]. | First Type of Controller Introduced by the Sanitary Devices Manufacturing Company, known as
the “Unloading Valve” | 167 |
| [100]. | Test of Controller Connected to Suction of 8-Sweeper Piston Pump | 168 |
| [101]. | Type of Controller for Use on Pumps Without Valves | 169 |
| [102]. | Regulator for Motor-Driven Vacuum Pump, Manufactured by the Cutler-Hammer Manufacturing Company | 170 |
| [103]. | Inspirator Type Vacuum Contactor, Used to Control Pilot Motor of Cutler-Hammer Controller | 171 |
| [104]. | Vacometer for Use in Testing Vacuum Cleaning Systems | 190 |